THE CANADIAN ENTOMOLOGIST. 209 



A NOTE ON THE ESSENTIAL CHARACTERISTICS OF 

 PRESTWICHIA AQUATICA LUBBOCK. 



BY A. A. GIRAULT, URBANA, ILL. 



This peculiar aquatic trichogrammatid has been so very little under- 

 stood in regard to its essential characteristics — its systematic position has 

 long been disputed and its characteristics erroneously described — that I 

 have drawn up the following descriptive notes. In the first place, I 

 desire to confirm its present position as a member of the Trichogram- 

 matidae ; and secondly, to state that I have before me several females of 

 it which agree exactly with the generic characteristics as at present 

 understood, and with the specific characters of the female as described 

 originally by Lubbock, and in general as recently figured by Schmiedek- 

 necht. The specimens were very kindly sent to me by Dr. Richard 

 Heymons, Director of the Konigl. Zool. Museum at Berlin, in the vicinity 

 of which place it was collected. It should be understood that the figure 

 of the female given by Schmiedeknecht is not correct in regard to the 

 details of structure. The same is true of the figure of the male given by 

 Willem. 



The following description is appended : 



Female. — Length, 1.45 mm., including ovipositor. 



General colour black-brown ; legs, antennae, all of thorax except 

 pronotum and mesoscutum, which are brown, tip of abdomen and sheaths 

 of ovipositor (last abdominal segment) and the ovipositor itself, gamboge ; 

 distal or third tarsal joint and tip of ovipositor darker. Mesoscutum with 

 distinct polygonal sculpture. Colours contrasting and characteristic. 



Wings appearing as described and figured by Willem for the male, 

 excepting that with these specimens a strong vein runs along the cephalic 

 wing margin of the minute fore wing, terminating before tip (the wings are 

 not developed to perfectness in the specimens before me, and casually 

 appear like those of the male ; in one specimen, however, I could plainly 

 discern the shrivelled portions of both a fore and posterior wing). Legs 

 long and slender, the coxae large, rounded, those of the posterior legs 

 much larger, conical, as long as the slender, proximal tarsal joints of those 

 legs ; femora only slightly thickened ; tibiae long and slender, setigerous ? 

 tarsi plainly 3-jointed, the joints long, longer in the caudal tarsi, there the 

 proximal tarsal joint longest, over a third longer than the posterior tibia, 

 long and slender but not greatly so ; proximal tarsal joint of the cephalic 

 legs short. Tibial spurs single, slightly curved, short, shorter on the 



June. 1911 



