Phlebotomus Flies 95 



seven African and six American. One species only, Phlebotomus 

 vexator, has been reported for the United States. This was described 

 by Coquillett, (1907), from species taken on Plummer's Island, Mary- 

 land. It measures only 1.5 mm. in length. As it is very probable 

 that this species is much more widely distributed, and that other 

 species of these minute flies will be found to occur in our fauna, we 

 quote Coquillett's description. 



Phlebotomus vexator, Coq. : Yellow, the mesonotum brown, 

 hairs chiefly brown; legs in certain lights appear brown, but are 

 covered with a white tomentum ; wings hyaline, unmarked ; the first 

 vein (Ri) terminates opposite one-fifth of the length of the first 

 submarginal cell (cell R2) ; this cell is slightly over twice as long 

 as its petiole; terminal, horny portion of male claspers slender, 

 bearing many long hairs ; the apex terminated by two curved spines 

 which are more than one-half as long as the preceding part, and just 

 in front of these are two similar spines, while near the middle of the 

 length of this portion is a fifth spine similar to the others. Length 

 1.5 mm. 



The life-history of the Phlebotomus flies has been best worked out 

 for the European Phlebotomus papatasii and we shall briefly sum- 

 marize the account of Dcerr and Russ (1913) based primarily on work 

 on this species. The European Phlebotomus flies appear at the 

 beginning of the warm season, a few weeks after the cessation of the 

 heavy rains and storms of springtime. They gradually become more 

 abundant until they reach their first maximum, which in Italy is near 

 the end of July (Grassi). They then become scarcer but reach a 

 second maximum in September. At the beginning of winter they 

 vanish completely, hibernating individuals not being found. 



After fertilization there is a period of eight to ten days before ovi- 

 position. The eggs are then deposited, the majority in a single mass 

 covered by a slimy secretion from the sebaceous glands. The larvae 

 emerge in fourteen to twenty days. There is uncertainty as to the 

 length of larval life, specimens kept in captivity remaining fifty or 

 more days without transforming. Growth may be much more rapid 

 in nature. The larvae do not live in fluid media but in moist detritus 

 in dark places. Marett believes that they live chiefly on the excre- 

 ment of pill-bugs (Oniscidae) and lizards. Pupation always occurs 

 during the night. The remnants of the larval skin remain attached 

 to the last two segments of the quiescent pupa and serve to attach 

 it to the stone on which it lives. The pupal stage lasts eleven to 

 sixteen days, the adult escaping at night. 



