DIPTERA 



295 



common and interesting. Its legs, which are banded with black and 

 white are held outspread as it flies and make it a very conspicuous object 

 as it drifts phantom-like through the air; and the false crane-flies 

 Anisopidce, some of which are mosquito-like with spotted wings and often 

 enter houses where they are found on window panes. Others of the genus 

 Trichocera, appear in swarms in autumn and early spring and sometimes 

 on warm sunny days in winter. 



Family Dixid^e 

 The Dixa-midges 



These midges closely resemble mosquitoes 

 in size and form; but the wing-veins do not 

 bear scales. The family includes only a single 

 genus, Dixa. 



The adult midges occur in the vicinity of 

 streams and in swampy places. 



The larvae are aquatic, living in ponds or 

 slowly running water ; they resemble somewhat 

 those of Anopheles but the body is almost always 

 bent so that the head and tail come close to- 

 gether. They progress by alternate thrusts of 

 the two ends of the body, the bent portion 

 traveling foremost (Fig. 504). 



Family Psychodid^ 



The Moth-like Flies 



There may be found frequently upon windows and on the lower sur- 

 face of the foliage of trees small flies which have the body and wings 

 densely clothed with hair and which resemble tiny moths in 

 appearance. The wings are broad, and when at rest slope at the 

 sides in a roof-like manner or are held horizontally in such away 

 as to give the insect a triangular outline (Fig. 505). The vena- 

 tion is peculiar; cross-veins are almost wanting (Fig. 506). 



The moth-like appearance of these insects is sufficient to 

 distinguish them from all other flies. 



Fig. 504. — Larva of Dixa. (After 

 Needham and Lloyd.) 



^TN 



Fig. 505. — A 

 moth-like fly. 



Fig. 506. — Wing of a moth-like fly. 



