SERPHOID AND CHALCIDOID PARASITES OF THE HESSIAN FLY 23 



malar space one third to one fourth the length of eye. The occiput is granularly 

 opaque with a few very delicate transverse striae just behind the vertex and 

 clothed with short hairs; vertex finely reticulately punctate, subopaque and 

 bare ; frons bare, above smooth and shining except along the eye margins where 

 it is weakly sculptured, below the middle finely reticulated and with some weak 

 transverse rugae just above the antennae; cheeks smooth; mandibles and 

 clypeus with a few long hairs. Antennae approximately half as long as the 

 body, 10-jointed, distinctly clavate, the club 5-jointed ; scape about as long as 

 the five following joints ; pedicel two and one half times as long as broad ; first 

 and second flagellar joints subequal and each about as long as pedicel, cylindrical 

 and more slender than the pedicel ; third flagellar joint about half as long as 

 the preceding joint, obliquely truncate at apex above ; fourth flagellar joint sub- 

 equal in length to the third but distinctly thicker, thickest at apex and a little 

 longer than broad ; fifth flagellar joint shaped like the fourth but a little longer 

 and much thicker ; sixth and seventh subequal in length and thickness to the 



Figure 5. 



-Trichacis remulus (Walker) : A, Adult female; B, antenna of female; C, an- 

 tenna of male. A, X 30. 



fifth but the apex not much narrower than the base, each very nearly as broad 

 as long; apical joint a little narrower than the preceding joint, ovoid, and a 

 little less than twice as long as broad ; the apical four joints each with a short 

 thick spur or spine near its ventral apical angle. Prothorax evenly clothed with 

 pale pubescence, and with very fine granular sculpture except immediately 

 behind the head where it is smooth ; mesoscuturn also evenly pubescent, very 

 faintly sculptured anteriorly, but smooth and shining posteriorly, the parapsidal 

 grooves distinct and complete; scutellum triangular, about as long as broad, 

 subconvex, smooth, pubescent over its whole surface and with a short pro- 

 tuberance near apex which is densely covered with short erect hairs, the 

 protuberance concealed and having the appearance of a tuft of yellow hairs; 

 mesopleura smooth, bare ; mesosternum smooth but pubescent ; metapleura and 

 propodeum strongly pubescent, the propodeum with two very distinct longi- 

 tudinal carinae medially, the groove between the carinae deep and bare. Fore 

 wing veinless or with only a trace of subcosta ; not twice as long as the abdomen, 

 evenly ciliated at base as well as on disk, marginal cilia short ; posterior wing 

 without discal cilia basad of the hooklets, the longest marginal cilia, which are 

 on the posterior margin near base of wing, longer than the breadth of wing 

 opposite their bases, but not equal to the width of wing beyond the hooklets. 

 Legs rather hairy. Abdomen about as long as head and thorax, more than twice 

 as long as broad, as broad as the thorax ; first tergite about as broad as long 



