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Classification: Cynipidae (Family) cynipids
Not all parasite wasps are invertabrate parasitoids, In fact the most obvious to the nature watcher are the Cynipidae family which are true parasites of plants. Although their host is totally different from the other families of parasitoids they still inject venom with their eggs which modifies the host tissues to form strangely shaped growths that are known as galls. These galls provides the larvae with nourishing food and protection from the outside world.
Ritchie (1993) noted that all phytophagous Cynipoidea are placed in this family. Members of Cynipidae either form galls on various plants or live as inquilines in the galls of other gall-forming insects.
Many gall wasps have two generations per year with each generation having a slightly different body shape and may well also reproduce differently, eg. It is quite common for the winter/ early spring generation to be parthenogenic (entirely female), and for those females to lay unfertilised eggs as well as normal fertilised ones that will develop into sexual males and females accordingly, which will appear in the summer/autumn generation.
It is well known that wasps have a haplo-diploid genetic structure that will produce females from fertilised eggs and males from the unfertilised eggs but the trick with these wasps is the ability to make females from unfertilised eggs. This is accomplished by the chromosomes inside the nucleus of the egg replicating as normal and then the two daughter cells coming into contact with each other, and the cellular membrane breaking down with the two haploid chromosones pairing up to form the full compliment of chromosomes and a diploid cell is created. Once this is done then the egg can divide as normal.
Some cynapids will produce different shaped galls in different plants according to which generation they are born in.
As well as fungus mycilia, which they can not run away from, gall wasp larvae frequently fall prey to a huge array of parasite parasitoids known as hyperparasites and cleptoparasites known as inquilines, which rather than attacking the larvae directly, will live in the gall along with them and steal their food. These communities can become very complex, involving many layers of inter-dependancy.
An example of the above is the Oak Marble gall (Andricus kollari) that in one gall can contain the cynapid wasp as the host that made the gall; upto 5 species of inquilines (Ceroptres arator, Synergus gallaepomiformis, S. pallidipennis, S. reinhardi and S. umbraculus) eating the hosts food; aswell as upto 13 parasitoid species (Eurytoma brunniventris, Sycophila biguttata, S. variegata, Megastigmus dorsalis, M. stigmatizans, Torymus geranii, T. auratus, Caenacis lauta, Hobbya stenonota, Mesopolobus amaenus, M. fasciiventris, M. sericeus, Eupelmus urozonus) living on the host, inquilines and each other.
Also the hyperparasitoids of species that have two generations per year can also change their body shape to follow their hosts through the generations, for example; by one generation to have a longer ovipositor than the previous one to reach the host.
There is disagreement about the limits of Cynipidae. Most European authors (eg., Quinlan 1979) have a broad concept of the family and recognize 4 subfamilies: Himalocynipinae, Austrocynipinae, Pycnostigmatinae and Cynipinae. In North American authors usually have a narrower concept, limiting the family to gall formers and inquilines. Ritchie (1993) considered that if this is accepted, then the other subfamilies should be given family status. However, this awaits further work on higher classification.
Ritchie (1993) considered the Charipinae as a distinct family, Charipidae. Species are defined by host association and negative morphological attributes (eg., the lack of sculpture). Adults are usually very small (1-3 mm) and are difficult to identify.
Two subfamilies, Alloxystinae and Charipinae were identified by Ritchie (1993). In this report we have considered the Charipinae as a subfamily of Cynipidae. The former considered species of Alloxystinae as hyperparasitoids of Aphidae (Homoptera) through Braconidae (Aphidiinae) and Aphelinidae. The early stages of the hyperparasitoid are spent inside its primary host, which is inside an aphid, but after the braconid or aphelinid pupates, the last larval instar of the alloxystine feeds externally and pupates inside the inflated aphid skin. Members of Charipinae are hyperparasitoids of Psylloidea (Homoptera) through Encyrtidae (Hérard 1986). There are 4 genera and circa 200 species worldwide.
Ritchie (1993) noted that many female Cynipinae have the hypopygial spine extremely well developed. However, males are difficult to identify, and it is often impossible to place them to genus. Gall-forming species on oaks and roses can be recognized by the extremely narrow pronotum (median dorsal length less than 1/7th the lateral height). Most species of Cynipinae form galls on Quercus (Fagaceae) in warm-temperate and subtropical regions. Sexual and agamic generations alternate in many oak gall formers. A few genera form galls on Compositae and Rosaceae, but rarely other plants. Cynipinae is restricted to the Holarctic region except for one species in South Africa (Rhoophilus loewi Kieffer) and 8 species in South America (Myrtopsen spp., Plagiotrochus suberi Weld). The Cynipinae contains circa 93 genera and 1,200 species worldwide.
Ritchie (1993) treated Eucoilinae as a distinct family Eucoilidae. They noted that the scutellum is medially with a characteristic round or teardrop-shaped raised plate ("cup" of old literature). They considered this the largest "family" of Cynipoidea.
Eucoilids are internal parasitoids of calyptrate Diptera larvae, emerging from the puparium. Many species are associated with dung or rotting fruit, but the family is not restricted to these habitats. The number of species worldwide is unknown, but most are found in the tropics, where they are abundant. In North America there are 15 genera and 78 species (10 in Canada). Specialists believe that 2-3X as many species exist.
The eggs of the parasitic members of the superfamily are uniformly of the stalked type, with the stalk, which is situated at the anterior end, ranging in length from less than that of the main body, as in Charips sp. (Fig. 37A), to several times its length. That of Figites anthomyiarum (Fig. 37B) is elongated and somewhat constricted in the middle and has a stalk of about equal length. In Eucoila keilini, the stalk is twice the length of the egg body, and in Ibalia leucospoides it is about four times as long. The chorion is thin and transparent and without surface ornamentation.
The known first instar larvae of the superfamily are of several distinct types. The "polypodeiform" larva of I. leucospoides (Fig. 37C) is unusually elongated, with a relatively large head, which is somewhat flattened dorsoventrally and is provided with falcate mandibles. Of the 13 body segments, all except the last bear a pair of fleshy, finger like processes ventrally, which are of uniform length. There are no integumentary spines or setae. The last abdominal segment is prolonged into a dorsally curved tail equal in length to the four preceding segments.
The first instar larvae of the several genera of Eucoilinae that have been described are distinctive and readily recognized and have been designated as "eucoiliform." The essential characters of this larval type that distinguish it from the polypodeiform are the long, paired, fleshy ventral processes on the thoracic segments only and an exceptionally long tapering tail. In Eucoila keilini (Fig. 38), the head is large and somewhat conical, and the body segmentation is indistinct. The fleshy thoracic processes are about half the length of the body and taper to a blunt point. The posterior segments of the abdomen are very much narrowed, being only very slightly wider than the base of the tail, and the tail itself is appreciably longer than the thoracic processes, is curved ventrally, and terminates in a sharp point. The segment immediately preceding the tail bears a fleshy conical lobe on the median ventral line. The integument of the posterior abdominal segments bears numerous short sclerotized spicules.
The larva of Cothonaspis rapae described by James and Malchanova is similar to that of Eucoila. There are at least seven distinct abdominal segments in addition to the two or more that make up the tail, and the latter organ is nearly as long as the entire body. There are a few setae upon the thoracic processes, and the distal third of the tail bears numerous spines.
The eucoiliform larva of Kleidotoma marshalli figured and described by James has 12 apparent body segments, and the body is much more slender than that of Eucoila or of Cothonaspis. The head is large, with the mouth opening distinctly ventral. The fleshy thoracic processes are much shorter, being equal only to one segment in length, and they bear no setae. Stout setae are present on the distal portion of the tail. The anal opening is indicated on the dorsum of the eighth abdominal segment.
The first instar larva of Figites anthomyiarum (Fig. 39C) is modified eucoiliform the thoracic processes being even more reduced than in Kleidotoma with the prothoracic pair only as long as wide, and the tail is short, almost cylindrical, and bluntly rounded rather than pointed at the tip. The segmentation is distinct, and the 12 body segments preceding the tail bear fleshy spines on the dorsum, these being largest in the mid abdominal region.
In the Charipinae, the only first instar larva that was described by 1940 was that of Charips sp. (Fig. 39B) by Haviland. This larva has few characters in common with other members of the family and must be considered as a modified caudate form. The head is large, equaling the thoracic segments in width, and is produced anterioventrally into a conical "proboscis." There are three pairs of sclerotized "nodules" ventrally and one pair dorsally, which presumably are sensory organs. The mandibles are long and slender. There are 13 body segments, of which the first 12 diminish gradually in length and width caudad. The last abdominal segment is broad at its base, tapers sharply, and terminates in a cylindrical, ventrally directed tail. This last segment is equal in length to the 9 abdominal segments preceding it. The anal opening is large, situated dorsally at the base of the last segment, and encircled by a sclerotized ring. The head, and the body segments except the last, are heavily sclerotized, and each of the body segments telescopes into the one preceding it.
None of the first instar larvae of the family that has been studied possesses any indication of a tracheal system, and respiration is consequently by diffusion only.
Second instar Larvae.
The second instar larvae of the Cynipoidea reveal differences that are almost as great as those in the first instar. In Ibalia, the paired ventral processes have disappeared, and the tail is somewhat reduced. The second instar larva of Cothonaspis rapae retains the eucoiliform characters of the first instar, but the segmentation is more distinct, whereas in Kleidotoma marshalli there is a change to the polypodeiform. The head of the latter is very large, exceeding the body segments in width and length, and the segmentation is exceptionally distinct. The minute paired processes occur ventrally on the first 10 body segments. The larva of Figites anthomyiarum (Fig. 40) is similar to Kleidotoma in all essential respects though the head is small, the segmentation indistinct, and the tail situated ventrally and at right angles to the axis of the body. An internal tracheal system is present, but there are no spiracles. The second instar larva of Charips sp. (Fig. 39A) is still of the caudate form, though the heavy sclerotization of the integument is lacking. Each of the thoracic segments bears a pair of small processes ventrally, and a pair of large conical structures is present at the posterior ventral margin of the head.
James studied the early instars of cynipoid larvae and came to the conclusion that the eucoiliform first instar larvae of Eucoila and Cothonaspis are derived from eggs which hatch in the middle of the protopod stage of embryonic development, whereas the polypodeiform larvae correspond, as the name implies, to the polypod phase. The form of the Figites larva, with its reduced appendages and distinct segmentation, indicates hatching in a later embryonic stage than does any of the other species discussed. The Charips larva, being devoid of appendages, is regarded as preceding or as being a very early form of the protopod stage. This view of the stage of development at the time of hatching is borne out by the occurrence of polypodeiform second instar larvae following the eucoiliform first instar in Figites and Kleidotoma.
Only three instars have been distinguished in the species studied, with the exception of Ibalia leucospoides, which has four. The third instar larva of Ibalia is cylindrical in form with the tail still further reduced and may be readily recognized by the presence of spiracles on the second and third thoracic segments.
The mature larvae of the various species differ in only relatively minor characters. That of Ibalia has the integument smooth and shining except in the pleural areas of the second to eleventh body segments, which bear rounded "bases" studded with minute spines. The mandibles are tridentate, whereas they ere bidentate in Figites and Charips. There is a somewhat surprising variation in the number and position of the spiracles. Ibalia has 10 pairs, situated on the second and third thoracic and the first eight abdominal segments; Eucoila keilini and Figites anthomyiarum have nine pairs, on the last two thoracic and the first seven abdominal segments; Cothonaspis rapae eight pairs, on the third thoracic and the first seven abdominal segments; and Charips sp. has only six pairs, on the second and third thoracic and the first, second, fourth, and sixth abdominal segments.
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The Figitidae are a small family of less than 100 species. Although they are cosmopolitan, they are best known from the Holarctic.
Important morphological characters include antennae not geniculate (elbowed); ovipositor emerging anterior to gaster apex; gaster laterally compressed, 2nd gastral tergite less than half as long as gaster (except in some Aspireratinae). Additional recognition characters include: gastral tergites nearly contiguous ventrally; body dark, 3-6 mm. long; abdomen petiolate; forms (Figitinae) with sessile abdomen have ringed petiole bearing longitudinal striations.
All know Figitidae are primary, solitary, endoparasitoids, mainly of larvae and pupae of Diptera (larval-pupal parasitoids). Some species parasitize lacewings (Neuroptera). A few species have been used in the biological control of root maggots in Canada.
Ritchie (1993) reported that the metasomal tergum 3 was the largest tergum in this family. The scutellum was usually modified (eg., with spines, additional pits or ridges). The female hypopygium is without a spine, and the head and mesosoma are usually heavily sculptured.
Figitidae is usually divided into 3 subfamilies: Anacharitinae, Aspiceratinae and Figitinae. The relationships between the subfamilies are unclear, and the subfamily Figitinae is artificial. Several genera appear to be intermediates between the subfamilies. The family contains 30 genera and circa 25 described species worldwide.
Clausen (1940) distinguished figitids from eucoilids by placing each in a superfamily. He considered the Eucoilinae as the best known of parasitic Cynipoidea, which were limited in their host preferences to Diptera. Oviposition is in the early larval instars, and adults emerge from the puparia.
Cothonaspis rapae Westw. is a parasitoid of cabbage maggot, Hylemyia brassicae Bouché. Only the first two larval instars of the host are subject to attack, and darkness is necessary for oviposition, although adults are diurnal (James 1928, Malachanova 1930). It was believed that this caused maggots in leaves and stems to be immune from attack. Parasitoid adults are attracted to infested cabbage, and no attention is paid to free larvae or to those which have been moved to a fresh plant. The life cycle is completed in circa 3 months, of which egg incubation takes 6 days and the larval period circa 2 months. Hibernation is in the mature larval stage, and there are two generations per year.
Eucoila keilini Kieff. was studied by Keilin & Baume-Pluvinel (1913) and Kleidotoma marshalli Mshll. by James (1928). Conspicuous ventral thoracic processes are thought to be adaptive only and to serve in locomotion and respiration. However James (1928) could find no evidence of their use in locomotion by Kleidotoma. Both of these parasitoids have two generations per year. Parasitized host puparia are smaller than normal size, which effect seems to be consistent in all Diptera attacked by Figitidae.
Observations on Psilodora sp., attacking blowfly larvae in dung and carrion, were made by Roberts (1935). He find the life cycle to take an average of 35 days under summer conditions, but there was a tendency for the pupal period to be prolonged, and some individuals remained in diapause for 7 months. Hibernation took place in mature larvae or prepupae in the host puparium. No thelytoky was found.
In his discussion of Cynipoidea, Clausen (1940) separated the figitids from the eucoilids, although their hosts were the same. Figites anthomyiarum Bouché attacks larvae of various Diptera found in decaying meat (James 1928). Oviposition occurs only in 1st or 2nd instar larvae, and a preference is shown for those which have just hatched. A temporary paralysis occurs, which is of 1-2 minutes duration. The initial stimulus for oviposition is most certainly provided by the decaying meat rather than by the maggots themselves (Clausen 1940/1962). Adults emerge from the host puparium. The cycle from egg to adult takes circa 60 days in summer, of which the egg, larval and pupal stages last 2-3, 38, and 20 days, respectively. There are 2 or possibly 3 generations per year and winter is passed as mature larvae in the host puparium. Adult life usually lasts only 8-9 days, and feeding is principally on juices of the host infested meat. There is a preoviposition period of circa 2 days, and an examination of the reproductive tract revealed the presence of several hundred mature eggs, suggesting a high reproductive capacity.
Clausen (1940) discussed the superfamily Charipinae separate from the Figitidae, noting work by Haviland (1921) and Spencer (1926). An undetermined species of Charips studied by Haviland is a solitary internal parasitoid of late larval instars of Aphidius ervi Hal. in Macrosiphum urticae Kalt. and of other Aphidiinae in various aphids. Oviposition takes place frequently in the 3rd or early 4th instar Aphidius larva, although sometimes also in the late 2nd instar and while the aphid host is still alive. The female mounts on the back of the aphid, orients herself with her head toward that of the host and inserts her ovipositor perpendicularly. The trophic membrane surrounding the embryo usually disappears at the time of egg hatching, but occasionally it persists until after the first molt. The 1st instar larva is usually found ventrally in the posterior or anterior 1/3rd of the host body and between the nerve cord and intestine. The last instar larva emerges from the host through a break in the skin behind the head and completes its feeding externally. This ectoparasitic phase lasts only circa 12 hrs. The pupal stage lasts 22-26 days, and adult emergence is effected by biting out an irregular hole dorsally in the host cocoon and aphid skin. Adults live only a short time, and feeding is on honeydew and plant sap.
Charips brassicae Ashm., studied by Spencer (1926) is similar in habits to that given by Haviland. The 1st instar larva is enveloped by the trophamnion, and feeding during the early stages is by diffusion through the thin integument. The aphidiine host is half grown when first attacked and reaches the pupa before death. The life cycle is completed in 26 days.
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Citation: UK Species Checklist from www.mapmate.co.uk/checklist
Ibalidae is a small family with less than 50 species. They are widely distributed but are not native to Australia. Important morphological characters include antenna 13-segmented in female, 15-segmented in male; hind basitarsus twice as long as remaining segments; 2nd tarsal segment of posterior leg with a long apical process extending to tip of 4th tarsal segment. The gaster is compressed laterally, longer than head and thorax combined. The forewing is often mottled with brown spots.
All known Ibalidae are primary, solitary, endoparasitoids of hymenopterous wood-boring larvae (Siricidae). They usually are egg-larval parasitoids. Several species have been imported to New Zealand, Australia and Tasmania for the biological control of siricid forest pests.
Ritchie (1993) noted that the forewing in this family possesses an extremely long thin radial cell. Tarsomere 1 of the hind leg is longer than the remaining tarsomeres combined, and the metasoma is greatly compressed and knife-like.
These are the largest sized Cynipoidea, with some species reaching 30 mm in length. The family contains a single genus, Ibalia, which is parasitic on Anaxyelidae and Siricidae. The larva feeds internally in the early stages, externally later. The family contains circa 15 species confined to the Holarctic, but one species has been introduced to New Zealand. In North America there are 7 species (4 in Canada).
Ibalia leucospoides Hoch. in Europe parasitizes Sirex cyaneus F. This parasitoid was colonized and established in New Zealand, and an account of its biology and behavior given by Chrystal (1930). When attacking its host in the latter's oviposition tunnels, the parasitoid ovipositor is inserted into the tunnel entrance and the stalked egg placed either in the egg of the host or in the newly hatched larva. Several of the 2-7 host eggs or larvae which are present in each tunnel may be parasitized, each with one insertion of the ovipositor. Sometimes the tip of the egg stalk remains fixed in the puncture in the integument. There is an increase of 3-8X in both dimensions during incubation, and the volume increase is thus very great.
The egg stage may last from six weeks to almost a year, advanced embryos having been found 3-4 weeks after oviposition. The trophamnion is very prominent and may envelop the 1st instar larva of some time, extending to almost a year. This is abandoned before the first molt, but persists unchanged in form during the succeeding larval stages and thus is not thought to have a nutritive function. The polypodeiform 1st instar larva is thought to be a relic of what was once an eruciform or active larval type (Chrystal 1930).Ibalia parasitism produces a strong effect on the feeding activities of young Sirex larvae. During the first year their tunnels are only half the length of those made by healthy larvae. A characteristic feature of the tunnels of parasitized larvae is that they tend to turn toward the wood surface, a tendency found in healthy hosts only at the end of larval development. The 3rd instar larva emerges from the host body and completes its feeding externally. Host body contents are completely consumed at this time and there is, thus, no feeding in the 4th instar. The 2nd and 3rd instars are comparatively short as compared with the egg and the 1st and 4th larval instars. The 4th instar may last almost one year. The pupal stage lasts 5-6 weeks. The entire cycle from egg to adult is not less than three years, and all stages may be found in the field at any time of the year.
Adults emerge after August, with males emerging first. They may be seen on the bark near the point where a female is about to emerge. Ibalia males mate with females while they are still in the act of oviposition.
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Ritchie (1993) reported that in this family the metasomal tergum 4, 5, or 6 in dorsal view is the largest tergum, and the metasoma is petiolate. The family is divided into 3 subfamilies: Liopterinae, Oberthuerellinae and Mesocynipinae. Oberthuerellinae is distinguished by the presence of a strong spine on the underside of the metafemur; Liopterinae has the metasomal petiole distinctly elongated; and Mesocynipinae has the petiole shorter than wide.
There is no biological data, but some evidence indicates that some are parasitic on wood-boring insects (Coleoptera: Buprestidae; Hymenoptera: Siricidae). The family contains 13 genera and 71 species worldwide, but they occur primarily in the tropics.
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