12 HOUSEHOLD INSECTS 



service in destroying flies, sometimes suspend a hornet's 

 nest in their parlors." Again, in 1869, Benjamin D. 

 Walsh, an American Entomologist, writes that "some 

 persons in America have turned this insect devouring 

 propensity of the hornets to good purpose by suspending 

 one of their nests in a house much infested by the common 

 house-fly. In such a situation we have been told that 

 they soon make a clearance of the obnoxious flies ; and 

 so long as you do not meddle with them they will not 

 meddle with you." It has never been the author's good 

 fortune to know any one personally who has used this 

 unique method of destroying house-flies. Under ordinary 

 circumstances we believe the good housekeeper would 

 rather take her chances of happiness among the house- 

 flies than with a good big nest of hornets as a kitchen 

 companion. 



There are several minute hymenopterous parasites 

 of the house-fly. Some of these are parasitic on the larvae 

 and some upon the puparia. It is probable that in certain 

 instances some of these parasites are numerous enough to 

 destroy many flies. However, much more remains to 

 be learned regarding the habits and destructiveness of 

 these enemies of the fly. 



A. A. Girault and G. E. Sanders of the University of 

 Illinois have given a good deal of attention to the parasites 

 of the house-fly. Many of their observations have been 

 published in the entomological magazine, Psyche, within 

 the last two or three years. In one instance, at least, 

 they found a certain parasite so abundant that it destroyed 

 as high as ninety per cent of its host. One could wish 

 that this enemy of the house-fly occurred more fre- 

 quently and were more widely distributed. 



