CHAPTER XI. 



HOUSE FLIES AND BLUEBOTTLES. 



THE swarms of flies which in the summer months 

 invade our houses, and disturb our peace, both of mind 

 and body, are of several different kinds. Popularly, 

 the smaller species are usually called indiscriminately 

 "house flies," or, indeed, simply " flies," and the larger 

 ones " bluebottles," whereby names that, strictly speak- 

 ing, belong to certain species only, are vaguely used for 

 a variety of forms more or less distinct. In the heading 

 to this chapter we have deferred to popular usage, and 

 intend to include under these two well-known names all 

 members of the family Muscidce that render themselves 

 obnoxious to us in our indoor life, either by their 

 persecution of our persons or their raids on our belong- 

 ings. At the outset, therefore, it may be as well to 

 make some attempt at discriminating species, that we 

 may know exactly what insects we are talking about. 



The Muscidce are an enormously large and very 

 puzzling family of the two-winged flies, which constitute 

 the order Diptera. Only a very few species of this great 

 family can in strictness be included as household pests, 

 and first on the list may be placed the house fly proper 

 (Musca domestica). This is a medium-sized and incon- 

 spicuous insect, which, at first glance, seems to have no 

 special adornment of any kind, but to be simply of a 



more or less uniform greyish black, with transparent 



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