245 



Family Pipunciilidae — The Big-headed Flies 



Tlii-s family is characterized by the very large head and thinly 

 pilose or i)ractically bare body. 



Head broader than the thorax, nearly spherical, composed chiefly 

 of tlie large eyes; eyes of the male contiguous above the antennae or" 

 closely approximated, in the female separated by a narrow front; face 

 narrow. Antennie small, three segmented, the third segment oval, reni- 

 form or aculeate below; arista dorsal. Ocelli present; proboscis small, 

 usually concealed. Abdomen composed of six or seven segments, small, 

 cylindrical; hypopygium conspicuous, often large; ovipositor usually 

 elongate and extending forward under the abdomen. Legs simple; tarsi 

 broad, the basal segment elongate; pulvilli present. Wings much longer 

 than the abdomen; ])asal cells elongate; anal cell reaching close to the 

 wing margin, rarely incomplete; apical cell narrowed apically but 

 always open; three posterior cells; venation incomplete in Chalaritft 

 Walker. Squama? vestigial. The wings are held flat over the abdomen 

 when the insect is at rest. 



The larva? are parasitic on bugs of the families CicadellidjB and 

 ]\Iirida\ and perhaps on other Homoptera and Heteroptera. The larvae 

 are elli])tical. thick, depressed and narrowed at either end, naked and 

 small. The oval, shining black puparia are o])tuse at either end and 

 somewhat smaller than the larvae. 



Pipunculida^ are found commonly wherever their hosts are to be 

 found, but more especially near the edges of woods, in clearings and 

 along shaded lanes. I have found tliem in large numbers in a small 

 clearing in whicli tlie ground was kept constantly moist from a spring 

 at one end and also along the edges of streams. Almost one hundred 

 species are known from North America, most of which belong to the 

 genus Pipunculus. Cresson* has monographed the family. 



Trans. Amer. Ent. Soc, xx.xvi, pp. 267-329. 



