CHAPTER IV 



THE FLY AND ITS ALLIES 



THE term "fly" is applied to many of the insects belong- 

 ing to the Diptera 1 or group of two-winged insects. 2 It is 

 strictly applied to the family Muscidse. 3 The most gener- 

 ally known representatives of this family are the house-fly 

 with a sucking mouth, the stable-fly with a mouth fitted for 

 piercing skin and sucking blood, and the blow-fly with a 

 steel-blue abdomen. These flies love sunshine and dryness. 

 On a bright day they fly actively in the open air. On 

 damp days, on the other hand, they swarm into houses and 



1 8/j, twice ; irrepbv, wing. 



2 The following is a key to the principal suborders of the Diptera : 



i. All three thoracic segments fused, usually winged ; 

 under lip unsegmented. 



61. Adults not parasitic ; maxillae covered by upper 



lip. 

 Ci. Antennae long, many-jointed . . . Nematocera 



(Gnats and Midgets," 



C2- Antennae short, usually 3-jointed ; the third 



joint ringed Brachycera 



(Flies) 



6 2 . Adults parasitic ; upper lip enveloped by max- 



illae as by a sheath Pupipara 



(Ex. Sheep-tick) 

 2 - The three thoracic segments separate, no wings, 



under lip segmented ...,. Aphaniptera 



(Fleas) 



3 musca, fly. 



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