DIPTERA 869 



ventral sclerites of the abdomen are present, and frequently well- 

 developed, surrounding the sclerites. Vein M1+2 is bent so that cell 

 R5 is narrowed or closed at the margin of the wing; in some genera 

 vein Mi+2 joins R44-5 at a considerable distance before the margin of 

 the wing. The abdomen is not armed with macrochasta?. 



There are only a few records regarding the habits of members of 

 this family. Some species are parasitic on adult Coleoptera, and 

 other on njonphs and adults of Hemiptera. 



Family MEGAPROSOPID^ 



This is a small group of flies the rank of which is in question ; some 

 authorities regard it as a distinct family and others, as a subfamily 

 of the Tachinid^. With these flies the clypeus is receding and short ; 

 the cheeks are very broad; the vibrissas are located near the middle 

 of the face; and the antennas are short. 



This family is represented in our fauna by two genera, Mega- 

 prosopus and Microphthalma. Microphthalma disjuncta has been bred 

 from the larva of PhylWphaga arcudta. 



Family CALLIPHORID^ 



The Blow-fly Family 



Certain members of this family are very familiar objects and are 

 commonly known as blow-flies, bluebottle-flies, or greenbottle-flies. 

 With these, and with most other members of the family as well, the 

 body, especially the abdomen, is metallic blue or green in color. 

 This fact has suggested the common names bluebottle-flies and 

 greenbottle-flies, that have been applied to certain species. These 

 names, however, merely indicate in each case the more usual color of 

 the species; for in all of the metallic colored species of this family 

 the color varies; it may be either violet, green, blue, or copper color. 



In this family the arista of the antennae is pliunose ; both the hypo- 

 pleural and the pteropleural bristles are present; the hindermost 

 posthimieral bristle is almost always more ventrad in position than 

 the presutural bristle ; and the second ventral sclerite of the abdomen 

 lies with its edges upon or in contact with the ventral edges of the 

 corresponding dorsal sclerites. 



The larvae of the different species vary in habits ; some have been 

 bred from cow-dung; some feed on fresh or decaying meat and on 

 the bodies of dead animals; one frequently infests wounds on animals, 

 and two are blood-sucking parasites of nestling birds. The following 

 are our best-known species. 



The blow-flies Calliphora: — The blow-flies normally live out-of- 

 doors, but they often enter houses in search of material upon which 

 to deposit their eggs. They then attract attention by their large 

 size, much larger than that of the house-fly, and by the buzzing noise 

 that they make. They lay their eggs upon meat, cheese, and other 



