V] FAMILY PSYCHODID^ 35 



CHAPTER V 



FAMILY PSYCHODIDyE (MOTH-FLIES AND SAND-FLIES) 



Definition. The members of this family are small insects, 

 generally not exceeding 5 mm. in length, which somewhat 

 resemble moths, as the body and wings are thickly covered 

 with hairs, amongst which patches of scales may occur. The 

 wings are unlike those of any other Nematoceran, being oval 

 or lanceloate in form (Fig. 19), and with a somewhat striking 

 venation. The second longitudinal vein branches into three near 

 the base of the wing, and as the transverse veins are very faint, 

 the wing appears to contain nine or ten longitudinal veins 

 without any connections. The antennae are long, being com- 

 posed of 16 segments, which often carry whorls of hairs. The 

 larvae, as a rule, live in decomposing vegetable matter. 



The Psychodidae are cosmopolitan, but are most abundant 

 in tropical and subtropical regions. The species belonging to 

 the genus Phlebotomus are the only ones which are known to 

 suck blood habitually. 



Phlebotomus. 



General account. All the members of this genus are small 

 inconspicuously coloured insects, the females of which feed by 

 sucking the blood of vertebrates. In some species the male 

 also sucks blood, and it often possesses mouth-parts resembling 

 those of the female. The flies are commonly known as " Sand- 

 Flies," or, in Southern Europe, " Pappataci Flies," and on 

 account of their voracious habits and the fact that their small 

 size enables them to creep through the meshes of an ordinary 

 mosquito net, they are a source of much aimoyance in those 

 parts of the world in which they occur, especially as their bite 

 causes great local irritation. Moreover, the well-known 

 " Pappataci Fever," or " Three-Day Fever," is certainly 

 carried by P. papatasii, and probably by other species of the 



