14 DINEUEA STILATA. 



Nematus stilatus, Thorns., Hym. Sc., i, 82, 3. 



xanthopus, Br. and Zad., Sclir. Ges. Konig., 1875, 

 Taf . iii, fig. 5 ; 1. c., 1883, 323, 69. 



Antennae subsetaceous, longer than the abdomen, the first two joints 

 half globose, third and fourth equal, the rest becoming a little shorter 

 and thinner towards the apex ; the basal two joints are black, the third 

 and fourth have a black line above, their under sides and the remain- 

 ing joints reddish. Head black, shining, covered with scattered 

 pubescence ; the sutures distinct, the front not much elevated. Cly- 

 peus emarginated at the apex, which, with the labrum, is white ; the 

 palpi are pale ; mandibles reddish at the tips. Thorax black, shining ; 

 mesonotum finely punctured ; the pronotum and a large spot on the 

 pleurae pale reddish ; pleurae somewhat opaque. Abdomen narrower 

 than the thorax, luteous, the two basal segments above, and sometimes 

 a mark on the apex, black ; cerci longish, pale luteous ; cenchri oval, 



Eale white. Legs yellowish; coxas and trochanters paler. Wings 

 yaline ; nervures black ; the costa and stigma sordid testaceous. 

 The has the thorax quite black ; the abdomen luteous, black above 

 at base and apex. 

 Length 2 2| lines. 



$ an <} ^ . Wings with one radial cellule. 



The neuration of the fore wings varies very much, 

 especially as regards the position of the transverse 

 radial and cubital nervures. In fact, as often as not 

 the transverse radial nervure is absent, and this cir- 

 cumstance puzzles entomologists not a little until they 

 become acquainted with the species. 



Larva : head yellowish-green, covered sparsely with 

 short white hairs. Mouth brownish. Body uniformly 

 green, sometimes with a yellowish tinge on the back, 

 which bears a microscopic pile. The sides over the 

 legs covered with white hairs, moderately long and 

 comparatively few in number. A narrow white line 

 goes down the sides through the spiracles. At the 

 last moult it becomes of a clearer green colour. 



The larvse feed on the upper side of the leaves of 

 the hawthorn, eating only the upper epidermis. There 

 are often two or three, or even more larvas feeding on 

 the same leaf ; they are sluggish and give out a fetid 

 odour. They are very similar to the larvae of D. testa- 

 ceipes, but the nasty smell which they give out enables 

 them to be distinguished from the Pyrus feeder. I 

 find them feeding from August to October. The flies 

 appear in June, and are common and generally dis- 



