THE WHITE-WINGED BIBIO: THE FLY DESCRIBED. Ill 



Walsh : in Pract. Entomol., ii, 1867, pp. 45^ 83 (habits). 

 Walsh-Riley : in Amer. Entomol., i, 1869, p. 237 (habits). 

 Packard : Guide Stud. Ins., 1869, p. 393 (mention). 

 Glover : MS. Notes Jouru.— Dipt., 1874, p. 4, pi. 3, f. 7. 



The white-winged Bibio, as, in the absence of a more popular designa- 

 tion, it may be called, is a very com- 

 mon species of fly, often met with 

 in great numbers in early spring in 

 our gardens and orchards. Its legs 

 and body are black — the latter elon- 

 gated and soft. The wings, as the 

 specific name implies, are white ; 

 they are traversed by brown veins, 

 upon one ofwiiich a blackish spot 

 rests near the front edge. The head 

 is small in the female, but in the 

 male it is large, and the contiguous 

 eyes occupy nearly all of its front, 

 as shown in Fig. 22. The head, 

 thorax and abdomen are clothed 

 with a short white down. The legs 

 of the fly, as well as the head, show 



whichj 

 however, have been imperfectly rep- 

 resented in the figures. 



The original description by Mr. Say, of the species, and accompany- 

 ing remarks are as follows ; 



B. alblpeiiniff. — Black, wings white, with a fuscous stigma. Inhab- 

 its Pennsylvania. 



Body with cinereous hair; head above with black hair; haltere!^ [bal- 

 ancers] fuscous ; scapns brown ; nervures brown ; tarsi black-brown, 

 exterior spine of the anterior tibia much larger than the interior ones. 



Length, three-tenths of an inch. 



This is a very common insect. The wings have a white appear- 

 ance and are strongly contrasted with the color of the body, and the 

 brown and definite stigma. The posterior tibiae of the males are much 

 more dilated toward the tip than those of the female. 



Fig. 22.— Bibio albipennis : a. the male flv ; /*, the 

 foMiale ; c, enlargement of the hea^ of the mal;' ; rf, marked SeXUal differences 

 ot I he temale ; /, front leg of the male ; e, hind leg ot 

 the same ; g, hind leg of the leinale. 



Family Characteristics. 



The family of Bibionidas, to which this species belongs, is of moder- 

 ate extent, as it contains only about fifty known United States species. 

 Embracing as it does species which are neither injurious to vegetation 



