204 OUR HOUSEHOLD INSECTS 



of them no doubt perish, while others are ultimately 

 wafted against the bodies of other flies to deal destruc- 

 tion among them as among their predecessors. The 

 particular species of fungus which makes havoc with 

 the house flies is called Empusa muscce, and is one of 

 a group which are distinguished by their habit of sub- 

 sisting upon living insects. The maturation of the 

 fungus involves the death of the fly, the fluids of whose 

 body serve as food for the parasite. Under its attack, 

 the fly becomes gradually feebler, and finally quite unable 

 to move, ai^d then the viscid secretion from the pads on 

 the feet hardens and glues the insect to the surface to 

 which it is clinging, while the fungus spreads round it 

 and leaves some of its spores adhering, so as to form 

 the halo above described. 



Besides the five species of which we have hitherto 

 been speaking, there are several other Muscidce that 

 frequent our houses, though perhaps none to so great 

 an extent as those already described. One of the 

 commonest of the less familiar species is Cyrtoneura 

 stabulans, which is at times almost abundant enough 

 to be classed with the other five. It is a very widely 

 distributed insect, occurring in the neighbourhood of 

 dwellings, not only in Europe but in America, and at 

 the Antipodes as well. As its name imports, it is fre- 

 quently abundant in stable-yards. It is a robust, dirty 

 grey insect, in size ranking next the bluebottles. The 

 thorax is distinctly marked with four dark longitudinal 

 streaks, consisting of the usual bare patches amongst 

 the grey tomentum ; the tip of the triangular hinder 

 termination of the thorax is reddish, and the legs, 

 except the tarsi, are of a clear yellowish or reddish- 

 brown. The neuration of the wings (Fig. 66) is very 

 similar to that of H. caniciilaris, but the chief nervures 



