178 MEDICAL ENTOMOLOGY 



resembles that of the Culicinae is inactive, and often has respiratory 

 trumpets. 



The Psychodidae are small hairy moth-like flies, commonly known as 

 'owl midges'. They are frequently seen in dark corners, on windows, or 

 in damp decaying grass, and about horse and cowdung ; their flight is 

 feeble, and is accompanied by a peculiar buzz. Nearly all the species are 

 hairy, and hold their wings arched over the abdomen, except the Phle- 

 botominae, in which the wings are raised above the body. As far as is 

 known at present, only the genus Phlebotomus contains blood-sucking 

 species, the well-known ' Papataci ' or ' Sand Flies '. These insects 

 have attracted considerable attention during the last few years on account 

 of the connection of Phlebotomus papatasi, Scopoli, with Papatasi or 

 Phlebotomus Fever. 



This febrile condition was described many years ago by Pym, an 

 army surgeon in Malta, but it remained one of the obscure fevers of 

 unknown origin until 1908 when Doerr studied it in Herzegovina. This 

 observer proved that the infection was transmitted by P. papatasi, 

 and Birt and others have since confirmed his work. It is now known 

 as the result of actual transmission experiments in Malta, Crete and 

 in London, that the fly is infective seven to ten days after ingesting 

 the virus of the disease, which is present in the blood of a sick person 

 during at least the first day of the fever. The disease is probably 

 widely distributed, and is believed to occur along the North-West 

 Frontier of India and in parts of South America. 



The family Psychodidae is usually divided into two subfamilies, 

 the Psychodinae and the Phlebotominae, which may be distinguished 

 by the following characters : 



Subfamily Psychodinae. Owl-like midges densely covered with hairs. 

 Seventh longitudinal vein without exception well developed. Second 

 vein forked once, or, as some consider, twice ; the first division is then 

 very near the base of the wing, the lower branch running out to the tip ; 

 the upper branch again forks nearer the base than the middle of the 

 wing. Proboscis short, not armed for piercing ; ovipositor strongly 

 chitinized and ending in a pair of flap-like valves ; male genitalia con- 

 sisting of two or three appendages. 



Subfamily Phlebotominae. Not such hairy moth-like flies. Seventh 

 longitudinal vein entirely absent, or if present markedly reduced ; in 

 a few instances it runs to the wing border. The second longitudinal 

 vein forks about the middle of the wing, and the upper branch again 

 divides nearer the tip than the middle of the wing. The proboscis 



