Eupelmus urozonus

Eupelmus urozonus is a member of the family Eupelimdae and has a large and varied host range and attacks species of several orders and habitats, in varying stages of development. It is theorised that it may be an aggregate of sibling species yet to be isolated and determined.

In Oak it is a parasitoid of; Andricus albopunctatus agamic, A. corruptrix agamic, A. curvator sexual, A. fecundator agamic, A. grossulariae sexual, A. kollari agamic, A. lignicola agamic, A. lucidus agamic, A. lucidus sexual, A. quercuscalicis agamic, A. solitarius agamic, A. testaceipes agamic, Biorhiza pallida sexual, Cynips divisa agamic, C. longiventris agamic, Neuroterus anthracinus (=A. anthracina) agamic, N. quercusbaccarum sexual

In Rose it is known to be a parasitoid of Diplolepis rosae and thought to be a parasitoid of Periclistus brandtii, D. mayri, D. eglanteriae and possibly others.

It may well hyperparasitise other parasitoids and has been recorded laying into Eurytoma brunniventris (Askew 1961).

It has also been found from Myopites olivieri (Dipt., Tephritidae) on Inula and Mikiola fagi (Dipt., Cecidomyiidae) on Fagus, from galls of a cecidomyiid (Etsuhoa thuriferae) on Juniperus thurifera, Blascoa ephedrae (Hym., Pteromalidae), Eurytoma gallephedrae (Hym., Eurytomidae) on Ephedra nebrodensis, Myopites galls on Inula and fruits of Juniperus phoenicea.

E. urozonus has been known to fly from january through to october, however, the life cycle has been found to be bivoltine (Askew 1961), with the first generation flying from the first three weeks in june and a later generation emerging from the end of july and the the end of september. Fully grown larvae have been found overwintering in Oak galls which have emerged in june and produced fast growing larvae which form the second generation later in the summer.

The female measures an average of 2.8mm, with a range of 1.8-3.4mm excluding the ovipositor.
The head is a dark metallic green, slightly hairy, with large dark brown eyes and small dark ocelli. The antennae are very dark with a dark green metallic scape, one ring and 7 funicular segments, which are not tapered, as well as a flat and wide club.
The thorax is a very dark metallic green with long but sparse decumbant white hairs. The notaulices are full length but shallow. The mesoscutum, scutellum and mesepimeron are reticulate. The tegulae are dark neutral brown in colour and lead to the wings which are clear, large and rounded. The veins and the hairs are transparent, with the stigmal vein being short and without darkening atthe head. The marginal vein is at least 2.5x the length of the post marginal vein. The Legs have dark metallic green coxae and femora, with yellow joints. The tibia and tarsi, which have 5 segments, are yellow with darker marks on the joints.
The gaster (abdomen) is again dark metallic green with, when seen from above has a square end, and is covered in short decumbant, white hairs. The ovipositor sheaths are dark and very short with a prominent yellow band in the middle.

The male measures 1.3-2.5mm, averaging out at 1.8mm.
Its head is dark metallic green with a concave front, Bright red, widely spaced eyes and dirty straw coloured ocelli. The antennae are dark brassy brown and hairy, with one ring, 7 funicular segments and a slightly swollen club.
The thorax again has a very dark metallic green top and is hairy. The notaulices are complete but shallow. The mesoscutum is reticulate but the scutellum is coriaceous and the mesepimeron is largely glossy. The tegulae are neutral brown and lead to the wings which are clear but with mid brown veins and hairs. The stigmal and post marginal veins are the same length and the marginal vein is at least 2.5x the length if the post marginal vein. The stigma and the uncus are both strongly marked. The legs have purple metallic coxae, which show up characteristly in day light, and dark green or brown femora with neutral brown tibia and pale neutral brown tarsi, of which there are 5 segments.
The gaster is a very dark metallic greeny brown and hairy. It is flattened so as to look broad from above and thin from the side.

Askew described the oviposition of E. urozonus into an oak gall of Cynips divisa. The drilling proces was observed, lasting some 26 minutes before the egg was finally deposited into a chamber containing a full grown Eurytoma brunniventris. The egg was covered by the weaving of fine transverse strands of silk by the ovipositor of the female wasp, so that the egg appeared to be in a cocoon, bound to the wall of the chamber. The E. brunniventris larva had not been paralysed, as is the usual custom of Chalcids.

More detailed descriptions and identification keys are available from Robin Williams at the British Plant Gall Society.

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