293 



A PRELIMINARY NOTE ON THE IDENTIFICATION OF SANDFLIES. 



By F. M. HowLETT, 



Agricultural Research Institute, Pusa, Bengal. 



(Plates XI and XII.) 



Some form of short-period fever, apparently sandfly fever, seems to have been 

 giving trouble in the GJallipoli area. This fact, together with the small amount of 

 information at present available on the life-histories of the species comprising the 

 genus Phlehotomus, has led me to publish the present note in the hope that it might 

 be of use to medical officers by giving them easily-seen characters by which the 

 early stages of three species may be differentiated. In collaboration with my 

 assistant Mr. Patel, I have been engaged for some time in collecting material for 

 a complete account of the life-histories of these species, but as the publication of this 

 memoir must be deferred to a later date, the present article contains merely a few 

 points w^hich are likely to prove useful under practical conditions of working in 

 the field, and a note on the very curious larval tail-bristles. 



The three species dealt with are those commonly found in India, Phlebotonws 

 2Mpatasii, P. argenfipes, and P. minutus. The first and last are already known to 

 occur in Southern Europe. 



The adult characters can be ascertained from the excellent works of Orassi, 

 Newstead, Annandale and Brunetti, and others ; the male genitalia are reliable 

 and easy characters, but the distinction of the females is not so easy. 



The pupae, to the tail of which the shrivelled larval skin remains attached, can 

 be differentiated by the structure of the genitals and caudal extremity generally, 

 as revealed by gently removing this larval skin, and by the number and arrangement 

 of the small excrescences bearing spines or bristles situated in the humeral region 

 of the pupa. 



But for practical purposes the characters of the egg and newly hatched larva 

 are most valuable, since almost any female which is caught full of blood will lay 

 eggs within a couple of days, if kept in an ordinary specimen-tube plugged with 

 cotton wool and containing a piece of wet blotting-paper which is not allowed to 

 dry up. Young larvae will hatch out under the same conditions in a week or ten 

 days, and either egg or young larva affords easy means of identification. 



Egg-Characters. 



When freshly laid the eggs of all three species are white, but they ultimately 

 become yellowish brown in papatasii, and smoky or dark brown in minutus and 

 argenti2)es. 



The egg of papatasii is the largest, argentipes intermediate, and minutus the 

 smallest, the last-named being about five-sixths the size of papatasii. The egg 

 of papatasii is drawn to scale in fig. 1, PI. xi. 



