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|Eulophidae (Forster 1856) - (Chalcidoidea).|
Aceratoneuromyia granularis Domenichini, 1967 |
Achrysocharoides acerianus (Askew & Ruse, 1974)
Achrysocharoides atys (Walker, 1839)
Achrysocharoides butus (Walker, 1839)
Achrysocharoides cilia (Walker, 1839)
Achrysocharoides latreillii (Curtis, 1826)
Achrysocharoides niveipes (Thomson, 1878)
Achrysocharoides splendens (Delucchi, 1954)
Achrysocharoides suprafolius (Askew & Ruse, 1974)
Achrysocharoides zwoelferi (Delucchi, 1954)
Aprostocetus aethiops (Zetterstedt, 1838)
Aprostocetus phloeophthori Graham
Asecodes coronis (Walker, 1838)
Asecodes hyperion Graham, 1963
Asecodes lagus (Walker, 1838)
Asecodes mento (Walker, 1839)
Astichus arithmeticus (Förster, 1851)
Astichus solutus Förster, 1856
Aulogymnus arsames (Walker, 1838)
Aulogymnus euedoreschus (Walker, 1839)
Aulogymnus gallarum (Linnaeus, 1761)
Aulogymnus gallarum f. pulchra (Linnaeus, 1761)
Aulogymnus skianeuros (Ratzeburg, 1844)
Aulogymnus trilineatus (Mayr, 1877)
Baryscapus diaphantus (Walker, 1839)
Ceranisus lepidotus Graham, 1963
Ceranisus menes (Walker, 1839)
Ceranisus pacuvius (Walker, 1838)
Chrysocharis acoris (Walker, 1839)
Chrysocharis albicoxis Erdös, 1958
Chrysocharis amasis (Walker, 1839)
Chrysocharis amyite (Walker, 1839)
Chrysocharis anianus (Walker, 1839)
Chrysocharis argyropezae Graham, 1963
Chrysocharis assis (Walker, 1839)
Chrysocharis chilo (Walker, 1839)
Chrysocharis chlorus Graham, 1963
Chrysocharis collaris Graham, 1963
Chrysocharis crassiscapus (Thomson, 1878)
Chrysocharis elongata (Thomson, 1878)
Chrysocharis eurynota Graham, 1963
Chrysocharis gemma (Walker, 1839)
Chrysocharis idyia (Walker, 1839)
Chrysocharis illustris Graham, 1963
Chrysocharis laomedon (Walker, 1839)
Chrysocharis laricinellae (Ratzeburg, 1848)
Chrysocharis liriomyzae Delucchi, 1954
Chrysocharis melaenis (Walker, 1839)
Chrysocharis moravica (Malác, 1943)
Chrysocharis naenia (Walker, 1839)
Chrysocharis nautius (Walker, 1846)
Chrysocharis nephereus (Walker, 1839)
Chrysocharis nigricrus (Thomson, 1878)
Chrysocharis nitetis (Walker, 1839)
Chrysocharis nitidifrons Graham, 1963
Chrysocharis orbicularis (Nees)
Chrysocharis pentheus (Walker, 1839)
Chrysocharis phryne (Walker, 1839)
Chrysocharis pilicoxa (Thomson, 1878)
Chrysocharis polyzo (Walker, 1839)
Chrysocharis prodice (Walker, 1839)
Chrysocharis pubens Delucchi, 1954
Chrysocharis pubicornis (Zetterstedt, 1838)
Chrysocharis submutica Graham, 1963
Chrysocharis subpolita Erdös, 1958
Chrysocharis truncatula Graham, 1963
Chrysocharis varus (Walker, 1839)
Chrysonotomyia chiorogaster (Erdös, 1966)
Chrysonotomyia formosa (Westwood, 1833)
Chrysonotomyia germanica (Erdös, 1966)
Chrysonotomyia lanassa (Walker, 1839)
Chrysonotomyia smaragdula (Graham, 1963)
Cirrospilus abastor Walker, 1838
Cirrospilus argei (Crawford, 1911)
Cirrospilus curvineurus Askew, 1965
Cirrospilus diallus Walker, 1838
Cirrospilus elegantissunus Westwood, 1832
Cirrospilus elongatus Boucek, 1959
Cirrospilus lyncus Walker, 1838
Cirrospilus phorbas Walker, 1838
Cirrospilus pictus (Nees, 1834)
Cirrospilus salatis Walker, 1838
Cirrospilus singa Walker, 1838
Cirrospilus viticola (Rondani, 1876)
Cirrospilus vittatus Walker, 1838
Closterocerus trifasciatus Westwood, 1833
Colpoclypeus florus (Walker, 1839)
Crataepus marbis (Walker, 1839)
Derostenus gemmeus Westwood, 1833
Derostenus punctiscuta Thomson, 1878
Desmatocharis turcica (Nees, 1834)
Dicladocerus breviramulus Boucek, 1959
Dicladocerus euryalus (Haliday, 1843)
Diglyphus chabrias (Walker, 1838)
Diglyphus crassinervis Erdös, 1958
Diglyphus isaea (Walker, 1838)
Diglyphus minoeus (Walker, 1838)
Diglyphus pachyneurus Graham, 1963
Diglyphus poppoea Walker, 1848
Diglyphus pusztensis (Erdös & Novicky in Erdös, 1951)
Dimmockia brevicornis (Erdös, 1954)
Elachertus argissa (Walker, 1839)
Elachertus artaeus (Walker, 1839)
Elachertus charondas (Walker, 1839)
Elachertus gallicus Erdös, 1958
Elachertus geniculatus (Hartig, 1838)
Elachertus inunctus (Nees, 1834)
Elachertus isadas (Walker, 1839)
Elachertus nigritulus (Zetterstedt, 1838)
Elachertus olivaceus (Thomson, 1878)
Elachertus pilosiscuta Boucek, 197!
Entedon abdera Walker, 1839
Entedon armigerae Graham, 1971
Entedon calcicola Graham, 1971
Entedon cionobius Thomson, 1878
Entedon diotimus Walker, 1839
Entedon ergias Walker, 1839
Entedon euphorion Walker, 1839
Entedon fufius Walker, 1846 a chalcid
Entedon gracilior Graham, 1971
Entedon hercyna Walker, 1839
Entedon lixi Erdös, 1951
Entedon loti Erdös, 1944
Entedon metatarsalis Thomson, 1878
Entedon methion Walker, 1839
Entedon molybdaenus Erdös, 1944
Entedon pallicrus Erdös, 1944
Entedon parvicalcar Thomson, 1878
Entedon pharnus Walker, 1839
Entedon philiscus Walker, 1851
Entedon punctiscapus Thomson, 1878
Entedon rumicis Graham, 1971
Entedon sparetus Walker, 1839
Entedon subovatus Thomson, 1878
Entedon ulicis (Perris, 1840)
Entedon ulmi Erdös, 1954
Entedon urticarii Erdös
Entedon zanara Walker, 1839
Euderomphale cerris Erdös, 1961
Euderus albitarsis (Zetterstedt, 1838)
Euderus viridis Thomson, 1878
Eugerium isander (Walker, 1839)
Eulophus abdominalis Nees, 1834
Eulophus aeneicoxa (Thomson, 1878)
Eulophus larvarum (Linnaeus, 1758)
Eulophus pennicornis Nees, 1834
Eulophus smerinthicida Boucek, 1959
Eulophus thespius Walker, 1839
Euplectrus bicolor (Swederus, 1795)
Grahamia clinius (Walker, 1839)
Hemiptarsenus dropion (Walker, 1839)
Hemiptarsenus fulvicollis Westwood, 1833
Hemiptarsenus unguicellus (Zetterstedt, 1838)
Hemiptarsenus waterhousii Westwood, 1833
Holcopelte obscura (Förster, 1841)
Holcopelte sulciscuta (Thomson, 1878)
Ionympha came (Walker, 1839)
Ionympha ochus (Walker, 1839)
Melittobia acasta (Walker, 1839)
Mestocharis bunacularis (Dalman, 1820)
Microlycus harcalo (Walker, 1852)
Miotropis unipuncta (Nees, 1834)
Necremnus artynes (Walker, 1839)
Necremnus capitatus Boucek, 1959
Necremnus cosconius (Walker, 1839)
Necremnus croton (Walker, 1839)
Necremnus folia (Walker, 1839)
Necremnus leucarrhros (Nees, 1834)
Necremnus metalarus (Walker, 1839)
Necremnus tidius (Walker, 1839)
Neochrysocharis aratus (Walker, 1838)
Neochrysocharis arvensis Graham, 1963
Neochrysocharis clinias (Walker, 1838)
Neochrysocharis cuprifrons Erdös, 1954
Neochrysocharis dimas (Walker, 1839)
Olynx arsames (Walker, 1838)
Olynx euedoreschus (Walker, 1839)
Olynx gallarum (Linnaeus, 1761)
Olynx gallarum f. pulchra Mayr
Olynx skianeuros (Ratzeburg, 1844)
Olynx trilineatus (Mayr, 1877)
Omphale acamas (Walker, 1839)
Omphale admirabilis (Westwood, 1833)
Omphale aethiops Graham, 1963
Omphale aetius (Walker, 1839)
Omphale betulicola Graham, 1963
Omphale brevis Graham, 1963
Omphale breviventris Graham, 1970
Omphale chryseis Graham, 1963
Omphale clymene (Walker, 1839)
Omphale clypealis (Thomson, 1878)
Omphale coilus (Walker, 1839)
Omphale connectens Graham, 1963
Omphale epaphus (Walker, 1839)
Omphale erginnus (Walker, 1839)
Omphale lugens (Nees, 1834)
Omphale marica (Walker, 1839)
Omphale nitens Graham, 1963
Omphale phaola (Walker, 1839)
Omphale phruron (Walker, 1839)
Omphale radialis (Thomson, 1878)
Omphale rhesus (Walker, 1839)
Omphale rubigus (Walker, 1839)
Omphale salicis Haliday, 1833
Omphale telephe (Walker, 1839)
Omphale theana (Walker, 1839)
Omphale varipes (Thomson, 1878)
Omphale versicolor (Nees, 1834)
Parasecodella obscura (Thomson, 1878)
Peckelachertus anglicus Graham, 1977
Pediobius acantha (Walker, 1839)
Pediobius alcaeus (Walker, 1839)
Pediobius amyntas (Walker, 1839)
Pediobius brachycerus (Thomson, 1878)
Pediobius caenus (Walker, 1839)
Pediobius cassidae Erdös, 1958
Pediobius claviger (Thomson, 1878)
Pediobius clita (Walker, 1839)
Pediobius crassicornis (Thomson, 1878)
Pediobius dorycniellae Erdös, 1961
Pediobius epeus (Walker, 1839)
Pediobius epigonus (Walker, 1839)
Pediobius eubius (Walker, 1839)
Pediobius facialis (Giraud, 1863)
Pediobius foliorum (Geoffroy in Fourcroy, 1785)
Pediobius lysis (Walker, 1839)
Pediobius nigritarsis (Thomson, 1878)
Pediobius phyllotretae (Riley, 1885)
Pediobius pyrgo (Walker, 1839)
Pediobius saulius (Walker, 1839)
Pediobius termerus (Walker, 1839)
Pediobius tetratomus (Thomson, 1878)
Pholema microstoma Graham, 1963
Pnigalio agraules (Walker, 1839)
Pnigalio attis (Walker, 1839)
Pnigalio epilobii Boucek, 1966
Pnigalio longulus (Zetterstedt, 1838)
Pnigalio nemati (Westwood, 1840)
Pnigalio pectinicornis (Linnaeus, 1758)
Pnigalio phragmitis (Erdös, 1954)
Pnigalio pristiphorae Askew, 1965
Pnigalio soemius (Walker, 1839)
Pronotalia trypetae Gradwell, 1957
Ratzeburgiola cristata (Ratzeburg, 1848)
Stenomesius acesius (Walker, 1839)
Stenomesius maculatus Westwood, 1833
Stenomesius nemoranae (Rondani, 1870)
Stenomesius pulchellus Westwood, 1833
Stenomesius rufescens (Rossius, 1790)
Sympiesis acalle (Walker, 1848)
Sympiesis dolichogaster Ashmead, 1888
Sympiesis gordius (Walker, 1839)
Sympiesis grahami Erdös, 1966
Sympiesis gregori Boucek, 1959
Sympiesis notata (Zetterstedt, 1833)
Sympiesis sericeicornis (Nees, 1834)
Sympiesis viridula (Thomson, 1878)
Sympiesis xanthostoma (Nees, 1834)
Teleopterus delucchii Boucek, 1970
Teleopterus erxias (Walker, 1848)
Tetrastichus abydenus (Walker, 1848)
Tetrastichus actis (Walker, 1839)
Tetrastichus acuminatus (Ratzeburg, 1848)
Tetrastichus adalia (Walker, 1839)
Tetrastichus aethiops (Zetterstedt, 1838)
Tetrastichus agrilorum (Ratzeburg, 1844)
Tetrastichus agrus (Walker, 1839)
Tetrastichus alveatus (Graham, 1961)
Tetrastichus amethystinus (Ratzeburg, 1848)
Tetrastichus anodaphus (Walker, 1839)
Tetrastichus anysis (Walker, 1838)
Tetrastichus apama (Walker, 1839)
Tetrastichus arathis (Walker, 1839)
Tetrastichus arenarius (Erdös, 1954)
Tetrastichus aristaeus (Walker, 1839)
Tetrastichus arundinis Giraud, 1863
Tetrastichus asparagi Crawford, 1909
Tetrastichus aurantiacus (Ratzeburg, 1852)
Tetrastichus boreus Delucchi, 1954
Tetrastichus brachycerus Thomson, 1878
Tetrastichus brevicornis (Panzer, 1804)
Tetrastichus calamarius (Graham, 1961)
Tetrastichus cassidarum (Ratzeburg, 1852)
Tetrastichus catius (Walker, 1839)
Tetrastichus caudatus (Westwood, 1833)
Tetrastichus celtidis (Erdös, 1854)
Tetrastichus centor (Graham, 1961)
Tetrastichus charoba (Walker, 1839)
Tetrastichus cirsii (Kurdjumov, 1913)
Tetrastichus citrinellus (Graham, 1961)
Tetrastichus citrinus (Förster, 1841)
Tetrastichus clavicornis (Zetterstedt, 1838)
Tetrastichus clito (Walker, 1839)
Tetrastichus coccinellae Kurdjumov, 1912
Tetrastichus conii (Erdös, 1954)
Tetrastichus conon (Walker, 1839)
Tetrastichus crino (Walker, 1838)
Tetrastichus cyniphidum (Ratzeburg, 1848)
Tetrastichus daira (Walker, 1839)
Tetrastichus decisus Walker, 1863
Tetrastichus deioaces (Walker, 1839)
Tetrastichus diaphantus (Walker, 1839)
Tetrastichus dotus (Walker, 1839)
Tetrastichus ecus (Walker, 1838)
Tetrastichus eleuchia (Walker, 1839)
Tetrastichus elongatus (Förster, 1841)
Tetrastichus emesa (Walker, 1839)
Tetrastichus endemus (Walker, 1839)
Tetrastichus epicharmus (Walker, 1839)
Tetrastichus eriophyes Taylor, 1909
Tetrastichus eupolis (Walker, 1839)
Tetrastichus eurytus (Walker, 1838)
Tetrastichus evonymellae (Bouché, 1834)
Tetrastichus fabicola (Rondani, 1877)
Tetrastichus fageti (Graham, 1961)
Tetrastichus faucula (Walker, 1839)
Tetrastichus fulvipes (Förster, 1878)
Tetrastichus galactopus (Ratzeburg, 1844)
Tetrastichus galerucivorus Hedqvist, 1959
Tetrastichus gaus (Walker, 1839)
Tetrastichus gratus Giraud, 1863
Tetrastichus halidayi (Graham, 1961)
Tetrastichus humilis (Graham, 1961)
Tetrastichus hylotomarum (Bouché, 1834)
Tetrastichus ilithyia (Walker, 1839)
Tetrastichus incertus (Ratzeburg, 1844)
Tetrastichus incrassatus (Graham, 1961)
Tetrastichus julis (Walker, 1839)
Tetrastichus lacaena (Walker, 1839)
Tetrastichus lachares (Walker, 1839)
Tetrastichus lasiocera (Graham, 1961)
Tetrastichus leocrates (Walker, 1839)
Tetrastichus leucone (Walker, 1839)
Tetrastichus ligus (Walker, 1839)
Tetrastichus longicauda Thomson, 1878
Tetrastichus loxotoma (Graham, 1961)
Tetrastichus luteus (Ratzeburg, 1852)
Tetrastichus lycidas (Walker, 1839)
Tetrastichus lyridice (Walker, 1839)
Tetrastichus lysippe (Walker, 1839)
Tetrastichus macrops (Graham, 1961)
Tetrastichus malhamensis (Graham, 1961)
Tetrastichus mandanis (Walker, 1838)
Tetrastichus metra (Walker, 1838)
Tetrastichus miser (Nees, 1834)
Tetrastichus monesus (Walker, 1839)
Tetrastichus murcia (Walker, 1839)
Tetrastichus mycerinus (Walker, 1839)
Tetrastichus myrsus (Walker, 1839)
Tetrastichus novatus (Walker, 1839)
Tetrastichus nymphis (Walker, 1839)
Tetrastichus oreophilus Förster, 1861
Tetrastichus orodes (Walker, 1839)
Tetrastichus oxathres (Walker, 1839)
Tetrastichus pallipes (Dalman, 1820)
Tetrastichus pausiris (Walker, 1839)
Tetrastichus pedicellaris Thomson, 1878
Tetrastichus phalis (Walker, 1839)
Tetrastichus phineus (Walker, 1839)
Tetrastichus plangon (Walker, 1839)
Tetrastichus planiusculus Thomson, 1878
Tetrastichus praecox (Graham, 1961)
Tetrastichus pronomus (Walker, 1839)
Tetrastichus prosymna (Walker, 1839)
Tetrastichus pubescens (Nees, 1834)
Tetrastichus rabirius (Walker, 1839)
Tetrastichus racilla (Walker, 1839)
Tetrastichus rhipheus (Walker, 1839)
Tetrastichus rhosaces (Walker, 1839)
Tetrastichus rufus Bakkendorf, 1953
Tetrastichus sajoi (Szelényi, 1941)
Tetrastichus sandace (Walker, 1839)
Tetrastichus sinope (Walker, 1839)
Tetrastichus strobilanae (Ratzeburg, 1844)
Tetrastichus suevius (Walker, 1839)
Tetrastichus tachos (Walker, 1839)
Tetrastichus telon (Graham, 1961)
Tetrastichus temporalis (Graham, 1961)
Tetrastichus terebrans (Erdös, 1954)
Tetrastichus thysanotus Förster, 1861
Tetrastichus tompanus (Erdös, 1954)
Tetrastichus totis (Walker, 1839)
Tetrastichus triarius Walker, 1848
Tetrastichus trichops Thomson, 1878
Tetrastichus turionum (Hartig, 1838)
Tetrastichus tymber (Walker, 1839)
Tetrastichus tyrtaeus (Walker, 1839)
Tetrastichus ulmi Erdös, 1954
Tetrastichus upis (Walker, 1839)
Tetrastichus vaccus (Walker, 1839)
Tetrastichus vacuna (Walker, 1839)
Tetrastichus ventricosus (Graham, 1961)
Tetrastichus verutus (Graham, 1961)
Tetrastichus vincius (Walker, 1839)
Tetrastichus voranus (Walker, 1839)
Tetrastichus xanthosoma Graham, 1974
Tetrastichus xeuxes (Walker, 1839)
Tetrastichus xixuthrus (Walker, 1839)
Tetrastichus zoilus (Walker, 1839)
Trichoplectrus laeviscuta (Thomson, 1878)
Xanthellum transsylvanicurn Erdös, 1951
Eulophidae is a large cosmopolitan family with about 328 valid genera and 2972 species known as of 1993. Over half of the eulophid genera have been described from Australia.
Important morphological characters include antennae inserted below the frons, funicle 3-4 segmented, and the male antenna may be pectinate. The axillae are frequently extended anteriorly, thus the scapulae is usually incised. Tarsi are 4-segmented. There is a straight foretibial spur (calcar), darkly colored body and a lightly sclerotized body that warps badly after death.
Although most Eulophidae are primary parasitoids, many develop as hyperparasitoids and some as facultative hyperparasitoids. Most species are gregarious, although many solitary species are known. There are both ecto- and endoparasitoids known in the Eulophidae. There is a wide host range, but the majority of species parasitize larvae of Lepidoptera. However, representatives of a number of insect orders also are attacked, as are all host stages.
Eulophidae are often encountered as parasitoids of crop pests, and are considered valuable in natural control, although only few species have been imported for biological control.
Gibson (1993) remarked that the Eulophidae have a body that is with or without metallic luster, usually lightly sclerotized (often collapsed or shriveled when dry). The antennae have 5-10 flagellar segments; females usually with a funicle of 2-4 nonring-like segments and with a club of 3 or less segments. Male antennae have 6 or fewer distinct flagellar segments, and often without a distinct club. The prepectus is conspicuous, usually subtriangular. The mesoscutum either has notauli or they are absent. The scutellum sometimes has a pair of submedian longitudinal lines and/or 1-3 pairs of long paralateral setae. The axillae are often partly advanced anterior to the scutellum. Individuals usually are fully winged. The protibial spur is short, straight, simple. The tarsi have 4 tarsomeres. The mesosoma and metasoma are separated by a distinct constriction. The petiole is transverse to elongated.
Eulophidae is one of the largest chalcidoid families with circa 540 nominal genera and 3,900 nominal species. Infrafamily classification is unstable, but 4 subfamilies are generally recognized, as will be discussed below.
Eulophidae is one of the most important chalcidoid families economically speaking. Most species are primary parasitoids of concealed larvae, especially leafmining Lepidoptera, Diptera, Hymenoptera and Coleoptera; but the host range is extremely diverse. Some are phytophagous.
Gibson (1993) discussed each subfamily as follows:
The scutellum is mostly without submedian longitudinal lines, and has 2 or more pairs of sublateral setae. The axillae are not advanced anterior to the scutellum, or only slightly so. The mesoscutum may or may not bear notauli. The forewing venation is not interrupted at the base of the parastigma, and the submarginal vein is smoothly joined to the marginal vein. The submarginal vein is usually with 3 or more setae; the postmarginal vein is at least as long as the stigmal vein. Male antennae are often branched.
These species are mostly solitary or gregarious external parasitoids of Diptera, Lepidoptera, Coleoptera, Hymenoptera (usually of the larvae but rarely of the pupae of members of these orders), Homoptera and Heteroptera. Leafminers and free-living caterpillars are the most common hosts. A few species are phytophagous. Species of Euplectrus are unusual in that the gregarious external larvae feed dorsally on a lepidopterous host that often is freely moving, and once the host contents are consumed the larvae move below the emaciated host to pupate, each larva spinning a silken cocoon to retain the host and to separate itself from other larvae (Gibson 1993).
Have a scutellum usually with a pair of submedian longitudinal lines and with 2 or more pairs of long sublateral setae. The axillae are usually distinctly advanced anterior to the scutellum. The mesoscutum have entire and linear notauli. The forewing venation is somewhat interrupted at the base of the parastigma, the latter projecting basally to the tapered apex of the submarginal vein. The submarginal vein is usually with 3 or more setae, rarely fewer. The postmarginal vein is absent or distinctly shorter than the stigmal vein.
Species of Tetrastichinae are mostly internal primary parasitoids of the eggs, larvae, or pupae of Lepidoptera, Coleoptera and Diptera, but they have been reared from members of 10 insect orders. A few species are phytophagous, predaceous on gall mites (Acari or Nematoda, or parasitoids of thrips larvae (Thysanoptera). Melittobia spp. are parasitoids of aculeate Hymenoptera, their biology having been relatively well studied because of their strong sexual dimorphism, the development of 2 dimorphic generations on a single host, and the presence of fighting males (Gibson 1993).
Have the scutellum without submedian longitudinal lines, extensively setose or with 2 or 3 pairs of sublateral setae. The axillae usually are distinctly advanced anterior to the scutellum. The mesoscutum bears entire notauli. The forewing venation is indistinctly interrupted at the base of the parastigma. The submarginal vein is usually with 3 or more setae, rarely less. The postmarginal vein is at least as long as the stigmal vein.
Euderinae are internal parasitoids of the eggs or larvae of Lepidoptera, Coleoptera, Tephritidae (Diptera) and Cephidae.
Have a scutellum that is mostly without submedian longitudinal lines, and usually with 1 pair of sublateral setae. The axillae usually are not distinctly advanced anterior to the scutellum. The mesoscutum have usually incomplete notauli, rarely extending to the transscutal articulation. If so, then they are usually relatively shallow, wide impressions posteriorly. The forewing venation is distinctly interrupted at the base of the parastigma. The submarginal vein has 2 setae; the postmarginal vein is at least as long as the stigmal vein.
Species of Entedoninae are primarily internal parasitoids of Lepidoptera or Coleoptera larvae that are concealed in mines, stems, rolled leaves, etc. Ectoparasitism or hyperparasitism through Diptera and Hymenoptera, or parasitism of eggs or pupae occur but are uncommon (Gibson 1993).
This is a large family with many genera and species, many being frequently encountered as parasitoids of important crop pests (Clausen 1940/1962). Clausen (1940) discussed eulophids according to subfamily because of the wide range in host preferences and diversity in habits. Although not extensively used in biological control of insects, there is an outstanding example with Pleurotropis parvulus Ferr, parasitic on leaf mining hispid beetle, Promecotheca reichei Baly, a pest of coconut. This parasitoids was imported in Fiji from Java in 1932 and was credited with evoking complete commercial biological control. It was since colonized in a number of South Pacific islands where coconut is damaged by beetles of this genus.
Species of subfamily Eulophinae are usually small and often brilliantly metallic, and the males of many species have branched antennae. They are found primarily as external parasitoids of leaf miner of larvae of Diptera, Lepidoptera and Hymenoptera when they occur in stems. A frequently encountered genus is Eulophus, parasitic on stem boring lepidopterous larvae, Sympiesis on lepidopterous and dipterous leaf miners, Microplectron in sawfly cocoons and Cratotechus on free living lepidopterous larvae. Cushman (1926) noted host preference of Sympiesis, attacking coleopterous, hymenopterous and dipterous leaf miners and also develops as an external parasitoid of the eggs of Cimbex. He concluded that the location rather than the type of host is the determining factor in selection.
Even though most species of obligate primary parasitoids, a few are known to develop as hyperparasitoids. Dimmockia incongruus Ashm. and D. pallipes Mues. are gregarious secondary parasitoids of the gypsy moth, through Apanteles and other braconids, ichneumonids and infrequently tachinids (Muesebeck & Dohanian 1927). Cirrospilus is often reared from lepidopterous cocoons in which it develops as a secondary parasitoid, through the larvae and pupae of Braconidae and Ichneumonidae (Clausen 1940/1962).
Subfamily Tetrastichinae is cosmopolitan and its species are mainly primary parasitoids of immature stages of a variety of insects. In the dominant genus Tetrastichus, a number of species are egg parasitoids or predators and others attack the larvae or pupae of Coleoptera, Diptera and Lepidoptera. They are less frequently parasitoids of Chermidae and Cynipoidea and as predators on leaf mites. Some that attack Lepidoptera may be both primary and secondary in habit, while others are exclusively hyperparasitoids through Tachinidae and a variety of Hymenoptera. Species of Melittobia show a wide range of host preference, and many develop indiscriminately as primary or secondary parasitoids of a large number of hosts. The genus Thripoctenus is apparently limited to Thysanoptera.
Not very much is known regarding the host preferences and relationships of the subfamily Entedontinae. Available data suggests that the species are mainly internal parasitoids of larvae of Diptera, Lepidoptera and Coleoptera when they occur in cases and leaf mines and in cells in plant stems. Leaf mining Diptera, in particular the Agromyzidae, are especially prone to be attacked. A large number develop as hyperparasitoids. The most frequently found genera are Chrysocharis, attacking lepidopterous and dipterous leaf miners, and Pleurotropis, which develops in the larvae of Lepidoptera, Diptera, Coleoptera and Hymenoptera (Cephidae), etc., in stems of plants and also as a hyperparasitoid of other members of this and related families. Some species are known to be parasitic in or predaceous on the eggs of Homoptera and Coleoptera.
Subfamily Elachertinae is a small group of which only a few species are studied. These are usually external parasitoids of larvae of Lepidoptera, in particular Noctuidae, Geometridae and Tortricidae. Genera which are most frequently encountered are Elachertus and Euplectrus, both of which are cosmopolitan. Several species of the latter genus that have been observed are distinguished by their ectoparasitic development on free living hosts.
NEARCTIC (CANADA).-- Yoshimoto (1984) noted that "this is an extensive family. Adults usually have small weakly sclerotized bodies that often collapse and shrivel with drying. This family is distinguished by the following characters: Tarsi 4-segmented. Antenna at most 9-segmented (2-4 funicle segments), sometimes branched in male. Body usually metallic in color and, except for the subfamilies Eulophinae and Entedontinae, with well-developed notauli. Fore tibial spur short, straight, not distinct and curved as in Pteromalidae."
Burks in Krombein et al. (1979) and Bou…ek (1977a) placed the tribe Elachertini (formerly arranged as a subfamily) as a tribe of Eulophinae. Graham (1959) provided keys to subfamilies. Yoshimoto (1984) included the family Elasmidae as a subfamily, Elasminae, in the Eulophidae. Excepting this, he recognizes Eulophinae, Tetrastichinae, Euderinae and Entedontinae.
These are small to moderately sized species circa 13 mm. long, which are usually metallic blue green or golden green. They are identified by a head that is usually wider than long and broader than thorax; eyes often hairy; antennae usually inserted at level of posterior margin of eye; pronotum usually shorter than wide; scutellum with pair of bristles; submarginal vein of fore wing somewhat interrupted at base of parastigma; gaster either sessile or petiolate; ovipositor does not protrude apically (Yoshimoto 1984).
North American species are represented by 24 genera, of which 18 are known from canada. Yoshimoto (1970a, 1970b, 1971, 1973a, 1973b, 1973c, 1976a, 1977, 1978, 1980, 1981) revised the Nearctic Chrysocharis (Chrysocharis Förster), Chrysocharis (Nesomyia Ashmead), Mestocharis Förster, Achrysocharoides Girault, Chrysonotomyia (Chrysonotomyia Westwood), Chrysonotomyia (Achrysocharella Girault), Thripoctenoides Erdös, and Derostenus Westwood. Burks (1966, 1971a) revised species of genera Pediobius Walker and Horismenus Walker. Miller (19620 revised Achrysocharoides Girault (= Enaysma Delucchi). Other genera represented in Canada are Omphale Haliday, Closterocerus Westwood, Emersonella Girault, Rhicnopeltoidea Girault, Carlyleia Girault, Haplocrepis Ashmead, Neochrysocharis Kurdjumov, Horismenus Walker, Pediobius Walker, Entedon Dalman, and Paracrias Ashmead. Grissell (1981) described Edovum puttleri from Colombia, South America, which was introduced in 1981 into North America for the control of Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera) (Yoshimoto 1984).
Species contain internal parasitoids of the larval and pupal stages of many different hosts, principally leaf-mining Nepticulidae and Coleophoridae (Lepidoptera), and Agromyzidae (Diptera) larvae. Some species are known to be hyperparasitoids on Braconidae larvae. A few species are egg parasitoids of Araneidae (Araneae), while others are parasitoids of Thripidae (Thysanoptera) (Yoshimoto 1984).
This subfamily contains an assemblage of small to moderately sized species whose bodies are usually metallic. they can be identified by a head that is broader than thorax; eyes bare or with sparse minute pubescence; mandibles bidentate; antennae inserted above level of posterior eye margin; anelli minute, with 2 segments; antennal funicle with 4 segments; male antennae often with whorls of long hairs; notauli without carina; scutellum generally concave, longer than broad, with 4 setae; propodeum with distinct median carina; fore wing hyaline, with or without hair lines radiating from stigma; submarginal vein usually broken at junction of parastigmal vein; marginal vein longer than submarginal vein; postmarginal vein short, subequal or 1.5-2X longer than stigmal vein; admarginal hairs always present; speculum usually moderate to large; gaster sessile, usually longer than thorax (Yoshimoto 1984).
In North America there are four genera, of which 2 are found in Canada: Euderus Haliday and Astichus Förster. North American species of Euderus were revised by Yoshimoto (1971), and are placed in four subgenera, of which Euderus (Secodelloidea Girault) and E. (Euderus Haliday) are found in Canada. Species parasitize larvae or pupae of leaf-tying and leaf-mining Olethreutidae, Nepticulidae and Pyralidae (Lepidoptera), or stem-boring Buprestidae, of fungus-inhabiting Erotylidae (Coleoptera), and of gall-forming wasps (Hymenoptera). Some are hyperparasitoids on other parasitic Hymenoptera (Yoshimoto 1984). Astichus polyporicola Hedqvist (= notus Yoshimoto) was reared from woody and birch bracket fungi (Yoshimoto 1970a).
Two tribes, Eulophini and Elachertini are distinguished. The tribe Eulophini consists of moderate-sized species whose bodies are usually bright metallic. Species can be identified by the subrectangular head, broader than thorax; eyes usually without hairs; antennae usually inserted above level of ventral eye margins; male antennae often with 2-3 long branches or funicle segments; notauli incomplete or, if traceable to posterior margin, then shallow and converge posteriorly; scutellum with 4 bristles; submarginal vein of fore wing with more than 2 dorsal bristles and without break at parastigma; postmarginal vein never rudimentary, usually at least as long as stigmal vein; gaster usually sessile; ovipositor does not protrude apically (Yoshimoto 1984). Eulophini are represented in Canada by Pnigalia Schrank, Sympiesis Förster, Necremnus Thomson, Hemiptarsenus Westwood, Notanismorphia Ashmead, Diglyphus Walker, Eulophus Olivier, Dahlbominus Hincks, Dimmockia Ashmead, and Dicladocerus Westwood (Yoshimoto 1984).
Nearctic genera Pnigalio and Sympiesis were revised by Miller (1970). Taxonomic notes and a key to New World species of Diglyphus are found in Gordh & Hendrickson (1979). Yoshimoto (1976b) revised the North American species of Dicladocerus. Gahan (1941) revised the world species of Necremnus Thomson. Yoshimoto (1983) revised the 17 Nearctic species of Pnigalio. The Eulophinae contains external parasitoids of larvae and sometimes pupae of leafminers, mostly Agromyzidae (Diptera), and Gracillariidae, Tortricidae and Coleophoridae (Lepidoptera) (Yoshimoto 1988).
The tribe Elachertini is distinguished by being moderate in size, ca. 2 mm long; body usually fuscous or brownish and not metallic; head usually wider than long and broader than thorax; often hairy eyes; antennae usually inserted above level of posterior eye margin; notauli complete and deep; pronotum usually longer than wide; scutellum with 4 bristles, and usually with sublateral longitudinal grooves; submarginal vein of fore wing, with more than 3 dorsal bristles, smoothly joining parastigma; stigmal and postmarginal veins long; gaster often petiolate; ovipositor does not protrude apically (Yoshimoto 1984).
North American Elachertini consist of 18 genera, of which 9 are known from Canada: Euplectrus Westwood, Stenomesius Westwood, Elachertus Spinola, Hyssopus Girault, Pseudolynx Girault, Paraolinx Ashmead, Giraultia Gahan & Fagan, Cirrospilus Westwood and Zagrammosoma Ashmead (Yoshimoto 1984).
Girault (1916) revised Euplectrus, Gahan (1922) revised Ardalus and Miller (1964) revised Paraolinx of North America. Gordh (1978) revised species of Zagrammosoma of North America. Species are principally larval parasitoids of Noctuidae, Coleophoridae, Gelechiidae and Pyralidae (Lepidoptera) (Yoshimoto 1984).
This subfamily contains moderately sized species whose bodies are usually brown, black, or yellowish with or without metallic lustre. They can be distinguished by a head being about equal in length and width, longer than wide, or shorter than wide, somewhat convex as seen from dorsal view; eyes usually bare; mandibles bidentate; antennae usually inserted above level of posterior eye margin; anelli minute, with 3-4 segments; antennal funicle 3-4 segments; notauli usually deep and complete; pronotum short, broad; scutellum with 2 bristles and usually with 2 longitudinal grooves; submarginal vein disjointed at parastigma; marginal vein usually thickened; postmarginal vein reduced or absent; gaster sessile; ovipositor usually short, but long and prominent in Aprostocetus Westwood (Yoshimoto 1984).
Tetrastichinae are represented by 15 North American genera, of which 9 are known from Canada: Tetrastichus Walker, Aprostocetus Westwood, Ceranisus Walker, Galeopsomyia Girault, Syntomosphyrum Förster, Melittobia Westwood, Crataepus Förster, and Peckelachertus Yoshimoto. Graham (1975) synonymized Winnemana Crawford with Cirrospilus Westwood.
Species of Tetrastichus Walker of North America were revised by Burks (1943), Yoshimoto (1970b) described Peckelachertus diprioni, reared from Diprion frutetorum (Fab.) eggs. Bou…ek (1977b) provided a tentative key to genera and Kostyukov (1977) studied the comparative morphology of the subfamily, proposing a key to the subgenera of the genus Tetrastichus. They are internal parasitoids and mostly primary parasitoids of egg, larval, nymph and pupal stages of many insects. Some are secondary parasitoids or hyperparasitoids. The Nearctic host/parasitoid names are noted by Burks (1943), Peck (1963) and Burks in Krombein et al. (1979).
PALEARCTIC (EUROPEAN former USSR).-- Nikol'skaya & Trjapitcyn (1978/1987), as translated from the Russian, described this family as "Body length usually 1.0 to 3.0 mm, but larger forms are also known. Axillae usually protrude beyond imaginary line between tegulae. Large family; many genera and species are very common. Most species are primary and secondary ecto- and endoparasites of insects of various orders; many species are parasites of eggs. Some species have been recovered from egg capsules of spiders. Larvae of several species of Tetrastichinae are predators, destroying gall-forming mites. Palearctic fauna includes 77 genera with 892 species (52 genera with 252 species have been found in the European part of the USSR). Palearctic members of Eulophidae have been divided into five subfamilies: Eulophinae, Elachertinae, Euderinae, Entedontinae and Tetrastichinae."
AFRICA.-- According to Prinsloo (1980), the eulophids form an extensive and complex family, containing many species of economic importance. Like many other chalcidoids, they are poorly known in Africa, and with few exceptions knowledge of the family is restricted to scattered taxonomic descriptions and host records, while a large percentage of the fauna has yet to be described. Prinsloo (1980) elaborated as follows:
Relationships & Diagnosis.-- "Eulophids resemble aphelinids in many respects... but are distinguished from the majority of species in the family, and other chalcidoid families, by the four-segmented tarsi. The Elasmidae are also characterized by four-segmented tarsi, but in that family the hind coxa is greatly enlarged and flattened."
"Small to moderate in size, usually about 1-2 mm in length; body usually weakly sclerotized, often causing dry specimens to shrink badly; integument with or without a metallic lustre; antenna with a reduced number of funicle segments, the funicle at most with four segments, the male antennae sometimes branched; thorax usually with axillae produced forwards; parapsidal sulci usually distinct; scutellum often with two longitudinal grooves; fore wing with marginal vein long in relation to the short stigmal and postmarginal veins; tarsi four-segmented; abdomen with gaster distinctly constricted at junction with propodeum; ovipositor of female never protruding strongly."
Biology.-- "Eulophids are diverse in their habits and are known to be internal or external parasitoids of a wide range of insects, as well as certain Arachnida. The majority of species are primary parasitoids, but a number a also known to be hyperparasitoids. Many eulophids attack the larvae of their hosts, but some are egg or pupal parasitoids. There appears to be a preference for hosts of the Lepidoptera and Diptera, and especially those belonging to leafmining families."
"Tetrastichus is a large cosmopolitan genus, the species of which attack a large range of different hosts in different stages of development, and a number of species are important enemies of various injurious insects such as psyllids and the caterpillars of moths; and in southern Africa T. dryi Waterston (previously thought to be T. radiatus Waterston) is an important enemy of the citrus psylla, Trioza erytreae (Del Guercio). Most species of Tetrastichus are endoparasitoids, but ectoparasitism also occurs. Species of Euplectrus are interesting in that they are gregarious ectoparasitoids on Lepidoptera larvae, especially those belonging to the Noctuidae, and their hosts include major pest species such as various bollworms and army worms. Another genus of economic importance is Pediobius, the species of which are primary or secondary endoparasitoids of various insects, including Diptera, Lepidoptera, Coleoptera and Hymenoptera; species of this genus have been recorded as enemies of the pine emperor moth, apple leaf roller, cotton leaf roller and maize stalk borer. There are also species of Pediobius known to develop from the egg sacs of spiders. Melittobia is not well known from Africa, but undetermined species have been reared from the nests of aculeate Hymenoptera, and non-African species are said to be primary or secondary ectoparasitoids of the larvae and pupae of Hymenoptera."
African Eulophidae.-- "The poor state of our knowledge of this group has been mentioned, and like in the Pteromalidae, the fauna is best known from a few genera-- many of which also occur in other parts of the world-- which are of economic importance or which are morphologically distinct."
"The family can be divided into five subfamilies. Tetrastichus is the best known example of the cosmopolitan subfamily Tetrastichinae, and comprises many hundreds of species. This genus is also richly represented in Africa; the species are often blackish in colour; the antenna has three funicle segments, and the submarginal vein of the fore wing is, as in all members of the subfamily, interrupted near the wing base. Like the Tetrastichinae, species of the Euderinae and Entodontinae also have the submarginal vein interrupted. The Entodontinae differ generally from the other two subfamilies mentioned in that the parapsidal sulci are complete; and the Tetrastichinae are separated from the Euderinae by the two longitudinal grooves on the scutellum. The Entodontinae comprise several large genera of which Pediobius and Chrysocharis are probably best known. The two remaining subfamilies, the Eulophinae and Elachertinae differ from the others mentioned, in that the submarginal vein is not interrupted; the Eulophinae are separated from the Elachertinae by the incomplete parapsidal grooves. Euplectrus is a well known genus of the latter subfamily in which the body is often partly blackish and yellowish, the antennal funicle four-segmented, and the hind tibia always with two unusually long and slender tibial spurs."
INDIA & ENVIRONS.-- Hayat (1988) noted that "Eulophidae is a large family comprising about 300 genera and approximately 3,000 species. These are small to medium-sized chalcids which can be recognized at once by the four-segmented tarsi, straight spur of the fore tibia, and non-pedunculate wings. Otherwise, eulophids are taxonomically a very difficult group to study."
"The fauna of the Indian subcontinent is rather poorly known. There are several recent publications, but most of these deal with a few species and there is so far virtually no comprehensive study of the family from the region. In the present work I have done nothing more than to prepare a more or less workable key to the genera based mostly on published literature. I may, however, note that I am not very familiar with the group. Because of the non-availability of relevent literature some genera (Asympiesiella, Pediobopsis, Scotolinx) could not be included in the key. I also suspect that some of the species are placed in the wrong genera. However, the genera included in the following key are either definitely known from the area or are represented in my collection."
Classification.-- "Some of the earlier classifications were proposed by Foerster (1856), Thomson (1878), Ashmead (1899, 1904), Girault (1913), Nikol'skaya (1952) and others. I have, however, followed here the classification adapted by Bou…ek (for instance, 1964). He recognises five subfamilies: Eulophinae, Elachertinae, Euderinae, Entedontinae and Tetrastichinae. This classification of the family excludes both aphelinids and elasmids from Eulophidae."
AUSTRALASIA.-- Bou…ek (1988) stated that "The family name was first proposed by Westwood (1828: 6), as 'subfamily Eulophina' and is based on the oldest generic name of Chalcidoidea, Eulophus Mueller, 1764 (not found in Australasia). For several decades thereafter the present families Aphelinidae, Elasmidae and Tetracampidae were included in eulophids. Aphelinidae were separated from the complex by Förster (1856; as Myinoidae) in Europe, but in America they remained as part of Eulophidae, including the catalogue supplement by Burks (1967), and were attributed to Encyrtidae by Gordh (1979), whilst Peck (1963) followed the European authors and excluded them as a separate family. The closely related Elasmidae were recently downgraded to a subfamily of eulophids by Riek (1970), followed by Burks (1979) and Yoshimoto (1984). Tetracampidae are commented on under their own heading. Apart from these changes the limits of the group, whether called family or subfamily, have changed relatively little. The reason for this is the fact that the definition of Eulophidae has been relatively simple and stable: tarsi in both sexes 4-segmented and in the antenna generally up to 4 funicular segments. Although the present Eulophidae were split into 4 families by Nikolskaya (1952), viz. Elachertidae, Eulophidae, Entedonidae and Tetrastichidae, the idea found but few followers. Sometimes even the subfamilies are rather difficult to define; this does not mean that they are necessarily artificial groups. The main reason is that the simple characters used for separation of subfamilies are not easy to assess in certain species. This concerns the depth and form of the notauli, the broken or smoothly curving submarginal vein, the shortened postmarginal vein, even the bristles on the scutellum. These features are found to be aberrant in some genera (as a rule, apparently in the plesiomorphic state) and are then misleading, although other characters mostly indicate where the form in question rightly belongs."
"Eulophidae are divided into four subfamilies, viz. Eulophinae, Euderinae, Tetrastichinae and Entedoninae. The former Elachertinae (maintained until Riel, 1970: 917), separated from Eulophinae by the presence of the complete notauli, was shown not to be a natural group and the two have been united (e.g. Graham, 1975; Bou…ek & Graham, 1978b). The Eulophinae include Euplectrini (as a tribe), mentioned as subfamily Euplectrinae by Riek (1970: 917). On the other hand Euderinae were raised to subfamily by Graham (1959a). This system is maintained despite the fact that the regional fauna includes some forms with e.g. apparently more segments in the antennal funicle... In such cases the extra segment either is separated from the clava or constitutes an enlarged anellus (Noyesius), so that really the maximum number of the flagellar segments, 10, remains the same."
"The phylogenetic study of the family is still at a rudimentary stage and is hampered by the poor knowledge of many genera and of their proper groupings. The most primitive forms are found in Eulophinae and perhaps the most ancestral of them are the Anselmellini and the Keryini. The Anselmellini appear to be phytophagous, have a distinctly 11-segmented antenna and may be a plesiomorphic sister group of Ophelimini (Eulophinae). The single known specimen of Keryini has a 12-segmented antenna and although here placed in Eulophinae, it may be a plesiomorphic sister-group of Euderinae plus Tetrastichinae in which the proximal flagellar segments are reduced in size and often also in number. The groundplan number of antennal segments (including anelli) in Tetrastichinae is also 12 and if the link with Keryini is confirmed by further study the latter group can be raised to subfamily. The Euderinae and Tetrastichinae seem to be closely related and, apart from the antennae, both have a number of plesiomorphic features in common with the Keryini, Anselmellini and Ophelimini of the present Eulophinae. The plesiomorphic states seem to be manifested by the complete and deep notauli, lack of scutellar, sublateral or submedian grooves, separation of the gastral terminal tergites (preserved in Euderinae), etc. Similar to the situation in Pteromalidae the relatively primitive Euderinae include parasites of beetles, but these are found also in the Entedoninae (e.g. Entedon), a large subfamily regarded as the most derived one within the Eulophidae."
"Compared with other regions the Australasian fauna of Eulophidae is relatively rich, especially in the genera. Some genera include numerous species, and eulophids are present in all land ecosystems, individual species often in great numbers. Most of the species are entomophagous but a considerable number are, or are suspected to be, phytophagous. The exact biological data are still rather scarce, mainly because of the difficulties in identification. So far the exclusively phytophagous species known belong to the genus Anselmella, and at least some species of Ophelimus (= Rhicnopeltella) and Quadrastichodella, the former causing galls on leaves, the latter in the flowers of eucalypts, as proved by their introduction outside Australia. Furthermore at least partial phytophagy is known or suspected in several genera of Eulophinae (Aulogymnus) and Tetrastichinae, and in one genus of Entedoninae (Pediobopsis). The entomophagous eulophids include several species (Arachnoobius, some Pediobius) emerging from egg-sacs of spiders, Arachnoidea, but the vast majority attack Insecta Pterygota. Larval parasites predominate but some species oviposit in the host egg and are egg parasites. Some other are egg-larval parasites, if the development extends into the host larva, as it is with many eulophids of small size, e.g. certain Cirrospilus, Aprostocetus, Pediobius, Chrysonotomyia and allied genera. Entedon females oviposit into the eggs of the host beetles but the main development takes place in the larval stage. The pupal parasites are generally gregarious and hundreds of individuals may develop in one lepidopterous pupa (Trichospilus); also they often tend towards hyperparasitism, if the host already was attacked by some other (primary) parasite (some Pediobius and Tetrastichus). Sometimes the egg is laid in the vicinity of the host, rather than actually on it or within it, and eulophids which do this can be recognised by the presence of a few erect setae on the ovipositor (some Eulophini). Ectoparasitism, as far as recognised, is found widespread in Eulophinae and some Tetrastichinae. Euplectrini are exclusive gregarious ectoparasites on caterpillars, and the only group of species known to produce a loose cocoon for protection of their otherwise exposed larvae. The main host groups are Lepidoptera, Diptera and Coleoptera and these include many leaf-miners, gall-makers and insects whose larvae burrow in other plant tissues. Other eulophids attack eggs of Homoptera Auchenorrhyncha (many tetrastichines, e.g. subgenus Ootetrastichus of Aprostocetus), of cockroaches (Aprostocetus hagenowii), the species of genera allied to Ceranisus destroy certain thrips. The host spectrum will certainly expand with improved knowledge of the regional fauna."
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Parker & Smith (1933a) gave an extended account of Eulophus viridulus Thoms., a parasitoid of the European corn borer, Pyrausta nubilalis Hbn. It is a gregarious external parasitoid of the last three larval instars, and the number that develop on each host ranges from 2-3 to a maximum of 57. The average of the summer generation colonies was 7.6 as compared with 16.5 for the autumn brood and 23.3 in the winter generation (Clausen 1940/1962).
Females have a long gestation period, and at no time is there a large number of eggs in their ovaries. Host larvae are permanently paralyzed by the female's sting, and the eggs are laid indiscriminately on the body. Larvae develop rapidly, and the host is reduced to an empty shell within a few days. When mature the parasitoid larvae crawl some distance from the host and pupate in the host tunnel. The meconium is case in the form of a series of blackish pellets, after which the final larval molt occurs. The cast integument still envelops the tip of the abdomen of the pupa and fastens it securely on its dorsum to the wall of the tunnel. When the adult is ready to emerge, the pupal skin breaks transversely at the neck and longitudinally for a short distance along the median dorsal line of the thorax.
Winter is passed in the pupal stage in the host tunnel. Hibernation seems to involve a true diapause, for it is not possible to obtain early emergence by subjecting recently formed pupae to high temperatures. There are three generations each year, and adults of the first brood emerge late in April and May. The life cycle from egg to adult is circa 14 days under summer conditions.
Females predominate in the ratio of circa 2:1 in the field, but many colonies have been found to consist of only one sex, particularly females. Mating probably takes place in the host tunnel prior to emergence.
Microplectron fuscipennis Zett. is an external parasitoid of mature larvae, prepupae and pupae of the sawfly Diprion sertifer Geoff. and others of that genus in Europe. Extended biological studies have been done in connection with its introduction to Canada for the biological control of spruce sawfly, D. polytomum Htg. (Morris & Cameron 1935, Ullyett 1936, Reeks 1937). Oviposition occurs in the sawfly cocoons in rubbish on the surface of the soil or just beneath it. The host is partially paralyzed and 20 or more eggs are laid on the body, although a maximum of 120 individuals are able to reach maturity in a cocoon of D. sertifer. The average number varies greatly according to locality and ranged from 30.7 in Hungary to 72.5 in collections from Jugoslavia. The maximum number of eggs obtained from a single female was 215, and the average number of progeny produced ranged between 40-57. The number of cocoons that may be successfully attacked by a female is low.
The cycle from egg to adult is circa 20 days at 22°C. Ullyett noted that although high RH is conducive to maximum oviposition, it has little influence on larval development. This is due to the ideal conditions of the microclimate in the cocoon. The optimum developmental temperature is 20-35°C.
Hibernation occurs in the larval, prepupal or pupal stages and appears to be a true diapausae for many individuals begin hibernation as early as August. Morris & Cameron (1935) found that the sex ratio varied considerably in different geographic regions. There is a great preponderance of females, ranging from 4:1 in Jugoslavia to 6:1 in Hungary, and the former ratio was secured also in a large series of laboratory experiments. The lower Jugoslavian ratio may be correlated with the much higher number of individuals developing in each cocoon. Reeks found that the ratio among progeny of females known to be mated was 9:1
Taylor (1937) studied Dimmockia javana Ferr, a solitary external parasitoid of the coconut leaf miner, Promecotheca nuciferae Maulik, larvae, in Java. The preoviposition period ranged from 3-9 days and the oviposition capacity of females varied directly with their size. The normal number of ovarioles was six, but small individuals have a smaller number, resulting in the production of fewer eggs. The maximum egg deposition in one day was 18, representing 3 eggs per ovariole; but this occurred only when there had been no opportunity for oviposition for some time previously. Attack may be on host larvae in any stage of development from late first instar onward. Stinging of the larva inhibited further development, but the prepupa was able to complete its transformation. However, the parasitoid was able to continue its development on the pupa provided that feeding began before the pupal integument hardened. The sex ratio of progeny from small hosts was circa 1:1, and females predominated from larger hosts.
A departure from the normal hyperparasitic habit of the genus is found in Cirrospilus ovisugosus C. & M., which is predaceous on the eggs of the four-lined plant bug, Poecilocapsus lineatus F. (Crosby & Matheson 1915). Host eggs are laid in clusters in plant stems, and the parasitoid larvae burrow through the pith until encountering a mass. It then consumes 3-4 eggs before reaching maturity. It is thought that Euolophinae which attack leaf mining larvae usually kill the host at the time of oviposition. This habit is found in a number of species of Asympiesiella and Diaulinus, while Eulophus viridulus paralyzes the host instead of killing it. When hosts are killed, their bodies decompose rapidly, turn black and the contents liquify. All this before completion of larval feeding. However, in Cratotechus the host remains active. Eggs of C. opaculus Thoms. and C. longicornis Thoms. are laid externally on the dorsum usually, and larval feeding commences at this point. Eulophinae that attack hosts in mines, cocoons and tunnels usually oviposit loosely on or near the host body (Clausen 1940/1962).
Most species of Eulophinae have several generations each year, depending on availability of suitable stages for attack. Eulophinae also pass the winter primarily in the pupal stage, which is not typical of Chalcidoidea. In some species there is a distinct diapause. The second generation of Dimmockia incongruus pupae persist ca. 10 months, while the entire cycle of the first generations averages only 16 days. Microplectron fuscipennis, noted above, is an exception to this behavior.
The host is usually left when larval feeding is completed and pupation occurs in the surrounding area. The last larval integument surrounds a portion of the pupal abdomen and serves to attach it to the leaf surface or to the wall of the mine, tunnel or cocoon. Pupal integuments are very heavy, as in the Entedontinae, so that their form is retained after adult emergence. Integuments are first white but quickly change to dark brown or even black. Pupae either stand erect or frequently lie with their venters upward. Cratotechus species which develop on free living larvae of Lepidoptera on foliage, leave the host body and frequently pupate in a circle or ellipse about it, with heads directed toward the center (Clausen 1940/1962). Such have been termed tombstone pupae (see Clausen 1940/1962). Pupae are subject to a high degree of hyperparasitism when they occur on foliage without any covering, and a high percentage may be destroyed by other species of Eulophidae and related families. Two color forms exist among pupae of E. viridulus, some of the summer generation having a relatively thin and brownish colored integument, while those overwintering are heavy and black (Parker & Smith 1933)
Most tetrastichinids develop as internal parasitoids of the eggs, larvae and pupae of other insects. Melittobia species, except M. indicum Silv., develop externally and are highly specialized in the host relationship and habits as follows:
Tetrastichus is internal in most cases, such as T. blepyri Ashm., which is hyperparasitic on Pseudococcus through several Encyrtidae, and T. radiatus Waterh., which attacks the nymphs of Chermidae. There is a record of a parasitoid developing both as an internally and externally (Urbahns 1917). Out of 111 parasitized larvae of the clover seed chalcid, Bruchophagus gibbus Boh (= funebrus How.) examined, 106 bore T. bruchophagi larvae externally and five internally. A greater part of the larval development occurs in the host stage following that in which the egg was laid. T. asparagi Cwf. oviposits in the egg of the asparagus beetle, but larval feeding is not completed until the prepupal stage in the soil. T. giffardianus Silv. and M. indicum, that emerge from dipterous puparia, oviposit in the mature larvae just prior to pupation. T. crassinervis Thoms. is both a primary and a secondary parasitoid of Hyponomeuta malinellus Zell, and occasional individuals are found even in newly transformed adults, although they are unable to emerge (Voukossovitch 1932). When hyperparasitic through Disochaeta, adults are unable to make an emergence hole and die (Clausen 1940/1962).
A great deal of diversity in host relationships is illustrated by the species of Tetrastichus, parasitic in Coccinellidae. T. ovulorum F. is a solitary internal parasitoid of the eggs of Epilachna in India, whereas T. epilachnae Girard and T. coccinellae Kurdj. oviposit in mature larvae or pupae but emerge only from pupae. Both of these species attack predaceous beetles, and T. epilachnae additionally parasitizes phytophagous epilachna.
Even though most species of Tetrastichinae are parasitic in or on immature insects, several are also predaceous in habit. Ootetrastichus beatus Perk., attacking the sugarcane leafhopper, consumes the entire contents of the host egg chamber. T. schoenobii Ferr. was found by Pagden (1934) to be predaceous on the eggs of Schoenobius incertellus Wlk. in Malaya, and the larvae were also found feeding on young host larvae which remained beneath the egg mass for several days after hatching. T. verrucarii Balduf, parasitic on larvae of Cynipoidea, have larvae that may move from one gall to a contiguous one, consuming the larval occupants. T. Eriophyes Taylor is usually predaceous as larvae and is limited for food to Eriophyesribis Westw. occurring on currant buds.
Some species such as Melittobia indicum, have a large number of mature eggs in their reproductive system at the time of female emergence. Oviposition occurs immediately whether or not females have mated. Clausen (1940) believed it probable that many species are able to do this, but M. acasta Wlk. has a gestation period of 11-12 days.
When adult females feed on the body fluids of the host, as in Melittobia, there is no noticeable effect upon the host individual and such feeding does not reduce population density. Marchal (1905) reported host feeding for the first time on a T. xanthomelaenae Rond., attacking eggs of the elm leaf beetle. However, in some Tetrastichus and other genera, adult feeding may destroy a greater number of hosts than parasitization. Johnston (1915) recorded that 71% of 2,000 host eggs were consumed by female T. asparagi. Feeding does not occur on eggs where oviposition takes place, however. Several true egg parasitoids of Tetrastichus were noted to feed similarly. Thus, the habit is identical with that in the ichneumonid, Diplazon laetatorius F. which shows a similarity in its host relationships. Female T. coccinellae feed on fluids exuding from the wound made when attacking coccinellid larvae, and occasionally a feeding tube is constructed.
When oviposition occurs on exposed hosts, the female usually stands on the body and inserts her ovipositor perpendicularly. However, this is often not possible if the host is active and insertion is then made by a forward thrust between the legs. M. indicum inserts her ovipositor in the posterior end of the abdomen of the active trypetid larva and may be dragged about by it. These females frequently burrow into decaying fruit searching for their victims, which is also found in T. giffardianus. When ovipositing on nymphs of Diaphorina (Euphalerus) citri Kuway, T. radiatus places eggs on the ventral side of the body near the juncture of the thorax and abdomen (Husain & Nath 1924). When Thripoctenus russelli Cwf. attacks early stage thrips, the abdomen is curved beneath the body and the ovipositor is inserted near the caudal end, while in T. brui the female turns about and inserts it by a backward thrust into the lateral margin of the thorax. Marchal concluded that the repeated insertion of the ovipositor by Tetrastichus xanthomelaenae into elm leaf beetle eggs may be to disorganize the contents and prevent completion of embryonic development.
Clausen (1940) discussed Tetrastichus rapo Wlk, an indirect secondary parasitoid of Ascia and other Lepidoptera through Apanteles, Microgaster, Anachaetopsis, etc.. It places its eggs in the body of its primary host while this is still within the live caterpillar, which is usually in its last instar. T. rapo is obviously able to determine whether the active caterpillar contains a parasitoid larva without proving with the ovipositor. The host relationship was first noted by Martelli (1907) and later verified by Gautier & Bonnamour (1924) and (Faure (1926). Young caterpillars that re stung by the parasitoid frequently die from mechanical injury it is thought, though no eggs are laid. This parasitoid may also be a direct parasitoid of larvae and pupae of these Braconidae in their cocoons (Clausen 1940/1962).
The pupal tsetse fly parasitoid, Syntomosphyruum glossinae Waterst., also develops as a hyperparasitoid through Mutilla. In such cases the female reopens the perforation made in the puparial wall by Mutilla, using the hard pointed tip of the abdomen and oviposits through it (Clausen 1940/1962). In many species of endoparasitic behavior, the female lays her full quota of eggs for development in a single host at one insertion of the ovipositor. T. giffardianus lays an average of eight in each host larva attacked, and Melittobia hawaiiensis Perk. when attacking puparia of Diptera, deposits circa 20 in each batch, and she may remain for many hours with the ovipositor inserted (Clausen 1940/1962).
Reproductive capacity data for Melittobia species indicates 1,086 eggs by M. acasta as the maximum, but most species range from 30-70. Clausen (1940) reported on a female of Tripoctenus russelli as laying 38 eggs in one hour's time.
Faure (1926) noted that the eggs of Tetrastichus rapo were often found in the anal vesicles of Microgaster and Apanteles. At deposition they are placed only in the general body cavity but then float free in body fluids and lodge in the vesicle where blood circulation is slower.
Larval habits of Tetrastichinae have not been elaborated on probably because there is a lack of any specialization or unusual events that merit notation. The mature larva of T. ovivorax Silv., developing in Oecanthus eggs, emerges from the empty shell to pupate, which is not usual in egg parasitoids. Pupation of those species which develop internally in larvae or pupae may be either within the body of the host or outside it. The mature larvae of T. asparagi emerge from Criocerus prepupae and pupate in the cell containing it, while T. coccinellae pupates within the mummified host remains. T. crasinervis transforms within the pupa of its host lepidopteran. Mature larvae of T. taylori Ferr. emerge from Elasmus larvae and pupate in the mine of the secondary host, but when development has been in a pupa or in a larva of Promecotheca, the transformation occurs within the empty host integument. Mature larvae of T. radiatus utilize the host body as a covering and fasten it to the leaf surface with a few strands of silk prior to pupation, which is comparable with the habit of a number of species of Elachertinae on caterpillars. Species of Tripoctenus that attack thrips, slough off the host integument but retain it as a crumpled mass enveloping the pupa's abdominal tip.
Many species of Tetrastichinae are solitary, particularly those that are egg parasitoids of those of the genus Tripoctenus which develops on thrips. However, even among the former there are some that produce 2-3 individuals in each host egg. Among those attacking larvae and pupae, the maximum recorded is 338 Melittobia hawaiiensis on a single larva of Sceliphron, although Gater (1926) found 119 of what was regarded as the same species, from a puparium of Ptychomyia remota Ald. in Malaya. In Tetrastichus asparagi only 5-6 can develop in each asparagus beetle larva, but an average of eight T. giffardianus in pupae of the Mediterranean fruitfly.
The life cycle of Tetrastichinae is relatively short, the minimum period from egg to adult was 6-10 days recorded for Tetrastichus ovulorum in India. Most complete the cycle in 15-25 days, however. Buckell (1928) recorded a large difference in time required for the development of males and females of Melittobia chalybii Ashm. under experimental conditions, males requiring only 21 days as compared with 37 days for females. Related to the short life cycle, there is probably quite a few generations each year. Although some species are restricted to a single generation per year that corresponds to the host, most species have 2-3. T. xanthomelaenae has nine generations each season in Italy. This parasitoid is able to reproduce continuously during the entire period in which elm leaf beetle eggs are available in the field. Thripoctenus brui Vill. shows a close adaptation to the life cycle of the host. In northern Europe there is a single generation each year just as the host Kakothrips pisivorus Westw., while in Japan there are 4-5 generations on Thrips and Taeniothrips, both of which have several generations each season.
Hibernation often occurs in the mature larval stage in the host body or in the cell which contains it. A portion of the brood of M. acasta may pass the winter in the pupal stage. The hibernation habit of Tetrastichus xanthomelaenae was not determined, but no alternate hosts are known and it is thought that the adult females persist in sheltered places until the following spring. Thripoctenus russelli and T. brui pass the winter in the pupal stage. Sometimes the immature stages of Tetrastichinae may go into diapause for a long period. Parasitized pupae of Epilachna containing Tetrastichus epilachnae were collected by Giard (1896) in September, and he held them in a heated room until the following July, at which time many of the parasitoids were still in the mature larval or pupal stages.
The sex ratio generally shows a preponderance of females. All species of Melittobia that have been studied show females predominating in the ratio of 9:1 or greater, the extreme being 31:1 in M. hawaiiensis when developing on hymenopterous larvae. T. crassinervis and Tetrastichus sp. from elm leaf beetle eggs in Japan are the only species where the sex ratio is circa 50:50.
Unisexual reproduction has been found in T. asparagi, Thripoctenus russelli, Ootetrastichus beatus and Thripoctenus brui. In the case of the latter, both sexes were present with females predominating 3:1, however (Sakimura 1937).
Clausen (1940) details the genus Melittobia because of its interesting behavior. It was noted that host relationships and habits of this genus were studied in great detail. In particular M. acasta Wlk. was studied by Howard & Fiske (1911), Graham-Smith (1919), Picard (1923), Balfour-Browne (1922b), and Parker & Thompson (1928). M. chalybii Ashm. was studied by Buckell (1928) and in detail by Schmieder (1933, 1938). M. acasta is recorded for a variety of hosts and may be either primary of hyperparasitic. As a primary external parasitoid, it has been recorded from many Hymenoptera, in particular Apoidea, and also from Vespoidea, Sphecoidea, etc. As a hyperparasitoid, it attacks Ichneumonoidea, Chalcidoidea and Tachinidae. It has been reared experimentally on a number of hosts not attacked under natural conditions, such as Coleoptera and Lepidoptera pupae and spiders (Parker & Thompson 1928). In Camponotus pupae development is made possible by partial desiccation, which results in the formation of internal air cavities which simulate natural conditions for the parasitoid. Oviposition does not occur in Diptera prior to the hardening of the puparium.
Sexual dimorphism is pronounced among adults of M. acasta. Females are normal, with all appendages and organs fully developed, but males are apterous and without eyes. The males normally do not leave the cell, cocoon or puparium in which they develop, however. They transform a few days prior to the females and mate with them after the pupal skin is cast. These males fight among themselves until only one remains alive. No feeding has been observed in such males, but females feed extensively on body fluids of the host and are able to construct a feeding tube for this purpose if necessary. Such feeding does not affect the host sufficiently to interfere with later development of the parasitoids.
During oviposition the ovipositor may be thrust through the host envelope, of if this is thin, the female may bite a hole and enter the cell of the host larva. Only mature larvae of Hymenoptera are attacked, being usually stung into immobility prior to oviposition. Picard reported that the host larvae are killed by the sting, and they may remain in a suitable conditions for feeding by the parasitoid for 8-9 months. Parker & Thompson found that form and color have no significance as oviposition stimuli, and false cocoons that bear the host blood do not attract the parasitoids. The number of eggs laid on a host is influenced by its size.
Females predominate with males representing only 1-5% . Virgin females deposit less eggs than mated, which is about equal to the total number of male progeny in a normal brood. No further oviposition occurs until mating is finished, and this may be on occasion with one of the female's own male progeny from the small number of eggs already laid. Unmated females take a strong interest in these few developing progeny, frequently stroking them with the antennae, and her interest increases as the pupal stage is reached. No other instance of maternal care or interest in the progeny is known among Chalcidoidea (Clausen 1940/1962). An average of 35.6 eggs were secured from each unmated female of a series, the total period extending to 225 days; but this large number was induced by the removal of eggs as soon as they were laid (Balfour-Browne 1922b). Even if the virgin female has her abdomen distended with eggs, she refuses to deposit more until she is mated, after which she will immediately deposit the full quota. This is then over 90% female, but some males are produced. However, the supply of spermatozoa in the spermatheca is not adequate for the fertilization of the entire quota, and thus repeated mating is necessary. Because both sexes are produced after mating, it is concluded that the female was able to regulate the sex of her offspring.
In M. acasta the reproductive capacity is high, a maximum of 1,086 eggs being recorded from a single female. However, in this case oviposition was extended over circa three months, and the daily maximum was 31. Unmated females may live four months or longer, so that there is sufficient time available for the development of a brood of male progeny and for normal oviposition after mating with one of them. Two to five or more generations can occur each year, and two successive broods may develop on a single host larva. The cycle from egg to adult is a minimum of 17 days, of which two days are required for incubation of the egg, 8 days for larval development and 7 days for the pupa. Winter is passed as mature larvae or pupae in the host cell or envelope.
Schmieder (1933, 1938) studying M. chalybii, found some departures in habit from those of M. acasta. Although host preferences were similar, females were found to enter the host cell before it was sealed or to attack the larva before the cocoon was spun. Adults revealed a polymorphism in form comparable with that in social bees and wasps. The type form of the male was light brown and it had well developed ocelli and the eyes were represented by a black ocellus like spot on each side. In the second form the ocelli may be absent or vestigial, the eyes unpigmented, the wings smaller and the body color dark reddish brown. The type form of the female was brownish black, and the wings were fully formed; the second form was brown in color and had crumpled nonfunctioning wings, the exoskeleton was thinner, the sclerites less distinctly outlined and the abdomen was large and distended on emergence. The type form completes the cycle from egg to adult in circa 90 days, and adults live for 66-75 days. By contrast, the cycle of the second form was only 14 days and adults lived only a maximum of 30 days. The type form females had a gestation period of 11-12 days and might deposit a maximum of 500-800 eggs, while those of the second form oviposited the day of emergence, usually did not feed, and produced only 40-60 eggs. Virgin females produced up to 10 eggs only, and most of those did not hatch. Usually two complete broods developed on each host individual, the first consisting of both forms, and the individuals of the second form reached maturity quickly and produced a brood destined to be of the type form, which developed along with the type form survivors of the first brood.
Winter is passed in the mature second form larval stage. The type form ensures the dispersal of the parasitoid, while the second form is for reproduction only. Experiments showed that only type form females can be produced on a host after a small number of second form larvae have developed on it. This is explained on a nutritional basis, the food of the second form consisting principally of blood, while that of the following type form comprised a considerable portion of solids.
Generally circa 3% of the progeny of mated females are male, and although the proportion is small and is further reduced by combat, practically all females are eventually mated. According to Schmieder, the sex ratio seems to be an adaptive feature which conserves the food supply of the species for the almost exclusive use of the female sex, the sex which alone serves the dispersal of the species. Males of this species have been found to be haploid, derived from unfertilized eggs of either mated or virgin females, and this condition is generally lethal, but there is no evidence for the production of biparental males. A very small proportion of eggs were found to possess parthenogenetic potential (Clausen 1940/1962).
Taylor (1937) made extensive studies on the biology of this subfamily, with several species of Pleurotropis that are parasitoids of the larvae and pupae of Promecotheca, and of several other genera associated with this host. Pleurotropis parvulus is of interest not only because of its habits but from the point of view of effectiveness in host regulation. It is a gregarious internal parasitoid of all larval instars and the pupa. The number of eggs laid in a give host varies directly with size, thus, an average of three is laid in 1st instar larvae, while 17 is the average for 3rd instar larvae, prepupae and pupae. The minimum number that can reach maturity in the later instars is 5 and a lesser number cannot consume enough of the body contents and thus die. The reproductive capacity of P. parvulus is low, for large females produce an average of 77 eggs and small ones only circa 20. Examination of the reproductive system of females of different sizes revealed that small individuals consistently had smaller and fewer ovarioles, which was reflected in a reduced egg capacity.
The life cycle is completed in 19-21 says, of which circa 3 days are needed to incubate the egg, and 7, 1, and 9 days, respectively, for the larval, prepupal and pupal stages. Several species of the genus Pleurotropis develop consistently in the tertiary role (Muesebeck & Dohanian 1927). P. tarsalis Sash., and P. nawaii Ashm. were associated with the gypsy moth and related hosts of Apanteles, and they develop on the various species of secondary parasitoids that attack the larvae of that genus.
Bakkendorf (1933) studied a few other species of Entedontinae. Anellaria conomeli Bakk. is an internal parasitoid of the egg of Conomelus limbatus F. during its early larval period, but after consuming the contents of the one egg it emerges and completes its development as a predator. To accomplish this, it has to bore its way through the stem pith containing the host eggs so that it can reach them. A total 7-8 may be consumed before maturity. Taylor (1937) studied Achrysocharella orientalis Ferr., hyperparasitic on Promecotheca through Pleurotropis and Dimmockia. This parasitoid develops internally in mature larvae or pupae of primary parasitoids within the dead body of the coleopterous host. When parasitic in Pleurotropis, its early stages are internal, and it then emerges and, in the last stages, becomes predaceous on the remaining individuals of the group within the hispid skin. Larvae developing in Dimmockia do not have this external feeding phase.
In Achrysocharis promecothecae Ferr., parasitic in eggs of Promecotheca in Java, only eggs which are 10 days old or older, in which embryonic development is advanced, are selected for oviposition. Sometimes a parasitized egg may hatch, in which case the parasitoid completes its development in the 1st instar larva in the mine. Adults do not emerge through the exposed portion of the egg capsule, but through the ventral side and through the leaf epidermis. Howard (1891) described an unusual feature in Chrysocharis singularis How., parasitic on larvae of Lithocolletis in a leaf mine. The mature larva of the parasitoid builds a series of pillars in a circle about its body, which serve to hold the walls of the mine apart and thus protect the pupa following the molt. Such pillars may be formed of larval meconium, although they are probably derived from regurgitated material (Clausen 1940).
In most species the pupal integument is very heavy and black. After adult emergence the exuviae retain the pupal form rather than becoming a disassociated mass or being broken into pieces, as is generally found in the Chalcidoidea. Life cycles are very short, being completed in 15-20 days, of which one half the time is passed in the pupal stage. Pleurotropis tarsalis requires 28-40 days, of which the pupal stage covers a period of 18-26 days (Clausen 1940).
Members of this subfamily usually reproduce bisexually. In most species females predominate, the sex ratio ranging from 1.6:1 in P. metallicus Nees to 3:1 in P. benefica Gahan (Salt 1931), 2:1 in Achrysocharella orientalis, and 7.4:1 in Achrysocharis promecothecae. However this can be altered by the host stage attacked. Females predominate from 1st instar Promecotheca larvae in a ratio of 1.7:1, but from 3rd instar larvae and pupae it is 4.3:1. Males do occur in every generation.
The gregarious external parasitoid Euplectrus plathypenae How. was studied by Swezey (1924), R. C. Smith (1927), Wilson (1933) and Vickery (1929). The species attacks half grown or larger larvae of Noctuidae, in particular Cirphis and Laphygma in North America. It is readily recognized by the characteristic clusters of closely packed larvae upon the host body (Clausen 1940/62). Up to 45 parasitoids may develop on a single Laphygma larva.
Adults are long lived, beginning to oviposit within a day or two after emergence. Swezey recorded 213 eggs laid by a single female over two weeks. Eggs are not laid on the host larvae that are about to molt. During oviposition, the female stands on the body of the host, usually on the dorsum of the thorax or of the first two abdominal segments, and the eggs are placed in groups unevenly spaced, and at times in rows upon the integument, to which they are attached. Hosts are not paralyzed at oviposition, which leaves a chance for the female to be dislodged during oviposition and of the young larvae being injured while the host is active.
Eggs are white when first laid but change to brownish black or black as incubation ensues. Hatching takes place in circa 2 days and is accomplished by a longitudinal splitting of the chorion along the median dorsal line. Feeding begins immediately, and the body gradually enlarges and emerges from the egg shell. The shell remains on a ventral pad, which attaches the larva to the host, and to it the different exuviae are added. Larvae may not be contiguous in early stages, but as they grow they become very crowded, causing a noticeable compressing of the anterior portions of the body, and the individuals in the center of the group are forced into a vertical position. According to Smith (1927) the host larva dies at the time eggs hatch, while Swezey (1924) & Wilson (1933) noted that the parasitoid larva may complete feeding before death of the host.
The host's body contents are almost completely sucked out and the parasitoid larvae after completing feeding, leave their position on the dorsum, finding their way beneath the host, where they arrange themselves transversely and spin delicate cocoons within which pupation occurs. Clausen (1940) thought that they are improperly termed cocoons because they are merely thin webs of silken strands which fasten the ribbon-like host integument to the leaf surface and partition off the pupae from their neighbors.
The life cycle is short, from 10-15 days in summer, with the egg, larval and pupal stages taking 2, 4-6 and 4-7 days, respectively. Wilson recorded a sex ratio of 1.5:1 in the third brood and 9.2:1 in the 6th brood.
Observations on E. comstocki How., parasitic on cotton leaf worm, by Schwartz (1881) indicate that its habits are similar to those of E. plathypenae. The host is attacked in an early stage, when it is less than 1/3rd grown, and eggs are placed on the middle of the back rather than on the thorax. E. bicolor Swed. in Europe, attacking caterpillars of a large number of species, was studied by Silvestri (1910c), Thomsen (1928) and Bischoff (1929). Silvestri found the number of eggs placed on an individual host varied directly with the size of the host. Oviposition was rapid and eggs were placed at 1 mm intervals on the dorsum between the mesothorax and the 4th abdominal segment.
Noble (1938a) gave a detailed account of Australian E. agaristae Cwf., parasitic on caterpillars of the grape vine moth, Phalaenoides glycine Lew. A maximum of 60 may attain maturity on a single host, although the average is circa 18. In superparasitism all individuals of the brood continue feeding without combat until the food supply is gone, following which all may die or develop into dwarfed adults. Winter is thought to be passed as adults, and mated females survived for six months in the insectary.
Elachertus differs considerably from Euplectrus. One species studied by Tothill et al. (1930) is a solitary external parasitoid of caterpillars of Artona trisignata in Java. The female frequently feeds on the host body fluids, which kills the host. During stinging a fluid is pumped into the host by the female which causes a marked distention. The ovipositor remains inserted for 10 min. or more following which the female bites a hole in the integument of the thorax and sucks out body fluids. The single egg is placed dorsally between the 1st and 2nd abdominal segments. Just after hatching the young larva moves to the ventral side of the host body and takes up its feeding position between the thoracic and abdominal legs. If more than one egg is laid on a host, hatching of one causes immediate cessation of development of the rest. Tothill et al (1930) stated that "Apparently the young larva injects into the host some fluid which is toxic to the other eggs, and this fluid then reaches the latter by diffusion through the egg stalks." This explanation has been given for the death of surplus individuals among internal parasitoids and is plausible in those species showing appreciable growth of the egg during incubation as a result of imbibing fluids from the surrounding medium. However, in Elachertus only the pedicel of the egg is within the host body, and this, unless it comprises the micropylar area, which is not probable, would not provide a channel through which diffusion might take place. The host is temporarily paralyzed at the time of oviposition, and its activities cease completely when the egg hatches. Liquefaction of the body contents begins immediately and is thought to be due to the injection of some fluid into the body by the parasitoid larva. If so, the effect is in contrast to the preservative action of the fluids injected by the sting of many other parasitoids and thus this injection is for an opposite purpose (Clausen 1940).
Silvestri (1910c) studied Elachertus affinis Masi, a European parasitoid of the mature larva of Polychrosis ambiguella. Eggs (5-10) are placed within the host cocoon but not directly on the larva, and the latter is not paralyzed. Young larvae are very active and able to move about freely in the cocoon. The life cycle takes 11-13 days in summer.
Trichospilus pupivora Ferr. differs from the genera already discussed in being gregarious and internal on pupae of the palm caterpillar, Nephantis serinopa Meyr. in India (Anantarayanan 1934). An average of 55 eggs is laid in each pupa, and a maximum of 211 individuals was reared from a single host (Clausen 1940/62).
Euplectrus has interesting pupation habits. When the larvae finish feeding on the host and have completely sucked out the fluid contents, they leave the dorsal position and seek the underside of the deflated host, where they arrange themselves transversely, in a single orderly row in some cases, and prepare to pupate. A light weblike cocoon is formed which binds the host remains to the leaf, the latter thus serving as a protective covering. Several authors have called attention to the fact that the material from which the cocoon is spun is derived from the Malpighian tubules rather than from the salivary glands and that the slender tapering tip of the abdomen of the larva serves as an "arm" in the construction. The meconium is cast by the prepupa, and sometimes it is ejected from the cocoon. The pupa lies upon its dorsum and is attached to the substrate by means of the last larval exuvium, which envelops the tip of the abdomen.
Tothill et al. (1930) found that the solitary larva of Elachertus sp. similarly pupates beneath the host skin, and the pupa lies on its back with spiracular processes directed upward. Such "hooks" were considered to serve for protection in holding the host remains away from the body to permit normal respiration. The collapsed host remains enveloped the pupa closely, and the spiracles at the tips of the hooks were believed to be the only ones that function. According to Howard (1891), pupae of Elachertus cacoeciae How. are attached by the tip of the abdomen to the silk spun in the leaf roll by host Archips rosaceana Harr., while those of E. spilosomatis How. are found in a group among the long hairs on the dorsum of the abdomen of Diacrisia virginica F. larvae.
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The eggs of the great majority of Eulophidae are simple; they are oblong or ovatc to elongate, are often slightly arched, and have both poles smoothly rounded. The chorion is usually delicate and unsculptured, though in Microplectron fuscipennis it shows, under high magnification, minute, conical projections. In a number of species, the micropyle is distinguishable as a small thickened area at the anterior end.
The eggs of several genera of Elachertinae differ from those of the majority of the members of the family. Those of Euplectrus and Elachertus have been stated by several authors to have a pedicel at the middle of the mid‑ventral curve; this serves as an anchor in the skin of the host in the same manner as with the pedicellate eggs of other groups. Observations regarding its form and origin are incomplete. In the figure given by Silvestri for Euplectrus bicolor (Fig. 63A), the pedicel appears to be a definite adaptive modification possibly comparable to that of the tryphonine Ichneumonidae, and Tothill stated that it is "continuous with the egg shell" in Elachertus sp. It may prove, however, to be similar in origin to those of Euxanthellus and the male eggs of some Coccophagus, in which a fold of the unmodified chorion is knotted or twisted at the time of deposition and is inserted into the puncture in the host skin. An examination of the ovarian egg would probably clarify this point.
The pronounced darkening of the chorion of the egg during incubation, which occurs in Euplectrus plathypenae (Fig. 63B) and E. comrstocki, has not been observed in other species of the family.
Records of the number of larval instars of the different species show little consistency. Only three have been detected in Eulophus viridulus and Melittobia acasta, four in Pleurotropis parvulus, Tetrastichus ovivorax and Euplectrus bicolor and five in Microplectron fuscipennis.
The first instar larvae are hymenopteriform and somewhat cylindrical, with 13 distinct body segments, and they have no characters to distinguish them readily from larvae of related families. Occasional species bear fleshy protuberances or tubercles on the body. In Diaulinus sp. (Solenotus sp.) figured by Parker (1924), the sensory setae are borne upon distinct tubercles. The larvae of Dimmockia javana possess distinct intersegmental protuberances, which function as pseudopodia, on the mid ventral line from the second to the ninth body segments. Each segment bears a transverse row of minute setae on the dorsum and sides near the posterior margin. The last abdominal segment is bifurcate in Tetrastichus sp. (Berry, 1938); this species has been confused with T. xanthomelaenae from the same host, but the latter does not possess this character. Melittobia acasta has a row of minute spines at the anterior margin of each segment, and T. taylori has a double row in the same position. In T. avivorax (Fig. 64A), this row of spines occurs only dorsally on each segment except the first and in the Tetrastichus sp. mentioned above they encircle the segments. According to Silvestri (1910c), the row of spines occurs at the posterior margin of the segments in T xanthomelaenae. P. parvulus apparently lacks the sensory setae and cuticular spines.
The integument of a number of species bears a distinct sculpturing. That of T. ovivorax has a pebbled appearance, whereas in T. xanthomelaenae it is imbricated. Hyperteles intermedia Thoms. (Parker and Thompson, 1928) has irregular areas of minute tubercles on all body segments except the last two. There are three pairs of sensory tubercles on each thoracic segment and four pairs on each abdominal segment except the last, which has only one.
The majority of species that have been studied have an open tracheal system, with spiracles on the mesothorax and the first three abdominal segments. Euplectrus bicolor is said to have five pairs, the additional one being on the metathorax. Several species of endophagous habit lack the open tracheal system, among them being P. parvulus, Tetrastichus taylori, Anellaria conomeli and Thripoctnus bruni.
The distinguishing characters of the first instar, particularly the cuticular spines and ornamentation, usually do not persist after the first molt, and the intermediate larval instars of the different species are consequently quite similar. In Diaulinus, however, the tubercles and setae are retained to the final instar, and this is true, also, of the two pairs of "papillae" on the last abdominal segment of Eulophus viridulus. In most species, the full complement of nine pairs of spiracles, situated on the last two thoracic and the first seven abdominal segments, appears in the second instar. They are stated to be on the mesothorax and the first eight abdominal segments of Melittooia acasta.
The mature larvae are usually of simple form, with very few integumentary spines or setae, and are usually without surface sculpturing. Tetrastichus eriophyes bears transverse striations, whereas T. ovivorax has the minute tubercles, mentioned for the first instar, ventrally. The larva of H. intermedia (Fig. 64B) bears numerous small integumentary tubercles in transverse rows both ventrally and dorsally on all body segments except the last. In Thripoctenus brui, the mature larva differs considerably from that of other genera in being cylindrical and about three times longer than wide, with both ends broadly rounded and no visible segmentation; it bears a transverse ring of about 12 short but stout spines at the middle of the body. The mandibles of Tetrastichus ovivorax bidentate, in contrast to the simple form of other species of the family.
The larvae of the gregarious species, such as Euplectrus (Fig. 63C) upon free living hosts, are pear shaped and are very broad in the mid abdominal region; the last four or five segments are much narrowed.
Nine pairs of spiracles are usually present, these being on the last two thoracic and the following seven abdominal segments.
Pleurotropis benefica, P. parvulus and Chrysocharis laricinellae Ratz. larvae only seven, those on the third thoracic and on the first abdominal segments being missing. In P. parvulus the number is said to be variable, usually smaller than the full complement mentioned, and it may differ on the two sides of the same individual. Thripoctenus brui and Anellaria conomeli lack the spiracles even in the mature larva, and Silvestri did not mention or figure them in Tetrastichus ovivorax.
The pupae of a considerable number of species, particularly of the Eulophinae, have an exceptionally heavy integument which m&y be jet black or dark brown in color. In a species of Elachertus found attacking Altona by Tothill, the pupa bears a pair of fleshy processes at the lateroventral margins of the seventh and eighth abdominal segments, each of which bears a spiracle at its tip.Information courtesy of www.faculty.ucr.edu
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