324 MEDICAL ENTOMOLOGY 



THE CALLIPHORINAE 



Medium-sized to large flies, usually of a bright metallic colour, but 

 sometimes yellowish. Eyes bare or pubescent; cheeks bare or hairy. 

 Arista usually plumose up to the tip, rarely bare, but sometimes pectinate. 

 Front in male as a rule narrow, sometimes wide, as in Auchmeromyia 

 and Bengalia. Thorax of a uniform colour usually without stripes or 

 bands ; either with or without tomentum between the bristles. Posterior 

 dorsocentral and acrostichal bristles well developed and as a rule con- 

 stant, but the former may be unequally developed. Sternopleural bristles 

 varying in number and arranged either 0:1; 7:7 or 2:1* Abdomen 

 round or ovoid, rarely elongate. Venation of the muscid type; bend 

 of fourth vein either angular or rounded. 



In this subfamily there are about twenty genera and at least 200 

 species. Although none of the imagines are true blood-suckers, many 

 of them frequent food, particularly meat when exposed for sale, and in 

 this way they may be found to contain blood. At least one of the 

 species belonging to the genus Ochromyia is predaceous in its imago stage, 

 feeding on ants ; this habit appears to be the exception rather than the 

 rule in the Calliphorinae. There are, however, several grades of parasitism 

 exhibited by the larvae of the Calliphorinae. As far as is known at 

 present, all the species are oviparous, and as a rule the females deposit 

 their eggs in decaying organic matter ; in the majority of instances they 

 prefer the dead body of some animal to any other situation in which to 

 deposit their eggs. Some of the flies, however, will readily lay their eggs 

 in sores and injuries on the skins of sickly animals; the larvae live on the 

 juices surrounding them. There are several species of Lucilia which 

 occasionally exhibit this habit and cause cutaneous myiasis. On the other 

 hand, there are many species belonging to several genera in which this is 

 the regular habit ; the females are attracted by any offensive smell and even 

 by shed blood, and will deposit their eggs in the skin and nostrils of man 

 and animals. The last grade of parasitism, and the one which Townsend 

 considers to be of recent origin, is well exemplified by the species of the 

 genus Auchmeromyia and Choeromyia ; their larvae are true blood- 

 suckers and bite man and animals. 



* This method of denoting the arrangement and position of the Sternopleural bristles is 

 commonly used by Dipterologists ; : 1 indicates that the anterior bristle is wanting and that 

 there is one posterior bristle, and so on. 



