

Fig. 542. Bibio olbipennis Say. 



HOW TO KNOW THE IMMATURE INSECTS 



10b. Ancd spiracles not noticecd)ly elevated, situated near base of 

 dorsal surface of caudal segment. 

 Fig. 542 Family BIBIONIDAE 



About 500 species of the March flies 

 have been described. The larvae live 

 in and feed on decaying vegetable 

 matter, dung, and the roots of grasses, 

 cereals and vegetables. They are some- 

 times very abundant. 



11a. Dorsal surface of 1st and 2nd abdominal segments each with 2 

 wart-like elevations. Fig. 543 Family DIXIDAE 



Only around 10 species 

 have been described in 

 the United States. The 

 larvae are aquatic and 

 feed on algae. The body 

 is bent and moves by al- 

 Fig. 543. Dixo sp. temote thrusts of the two 



ends of the body, the bent 

 portion is foremost. 



lib. Dorsal surface of 1st and 2nd abdominal segments without ele- 

 vated processes 12 



12a. All or some of the dorsal segments with narrow^ sclerotized strap- 

 like transverse bands; or the apical segment In the form of a 

 short sclerotized tube; rarely the ventral abdominal segments bear 

 a central series of sucker^like discs. 



Fig. 544 .Family PSYCHODIDAE 



The larvae are aquatic or 

 terrestrial and some live in 

 drain pipes. They feed on de- 

 caying matter, dung, fungi and 

 sewage. The adults are called 

 sand flies or moth flies. Some 

 sand flies are the carriers of 

 human diseases. Flebatomus 

 argentipes Annandale & Brun- 

 netti, F. major Annandale, F. 

 chinensis Patton & Kindle are 

 the carriers of kala azar. 



12b. Dorsum without narrow, sclerotized, strap-like bands; apical seg- 

 ment not in the form of a short sclerotized tube; ventral abdomin- 

 al segments never with sucker-like discs 13 



13a. Antennae undeveloped, appearing as pale roimd spots on side 

 of head; ventral surface of head with sclerites contiguous anter- 

 iorly, widely separated posteriorly. ...Family MYCETOPHILIDAE 



Fig. 544. Psychoda superba Banks. 



193 



