The Two-winged Flies 345 



pharynx, causing terrible pain and sometimes death. Indeed, out of twelve 

 cases which came to the knowledge of Dr. Richardson, an Iowa physician, 

 eleven resulted fatally. As many as three hundred screw-worms were taken 

 f.om the inner nose and region above and behind the soft palate of some 

 of the patients. As a pest of domestic animals the greatest injuries have been 

 caused in Texas. The eggs are laid in any open wound or in the nose or mouth, 

 and the quickly hatching larva? burrow into the adjacent tissues. Cattle and 

 hogs are particularly attacked, horses and sheep less often. 



In the states in which sugar-beets are grown some anxiety for the success 

 of this new industry new in this country, that is; sugar has long been made 

 from beets in Germany is felt because of the presence in the beet-fields 

 of an obscure little fly, Pegomyia vicina, which may be called the sugar-beet 

 midge. The eggs are laid on the leaves, and in three or four days the tiny 

 white larvae hatch and burrow into the soft leaf-tissue. When many of the 

 larvae are at work mining the leaves much injury to the plants results. In the 

 great sugar-beet fields along the California coast four or five generations 

 of this fly appear annually and occasion great loss to the growers. This 

 fly belongs to the subfamily Anthomyiinae, to which Muscid group two 

 other well-known fly-pests belong, namely, the onion-fly, Phorbia ceparum, 

 and the cabbage maggot-fly, Phorbia brassica. Both these insects in the 

 adult stage are small light-gray flies, looking rather like small house-flies. 

 The onion-fly lays its eggs on the stems of onion-plants, near the soil, and 

 the hatching larvae burrow into the underground bulb, which they soon 

 nearly destroy. This fly appears to live on no other plant. The cabbage 

 maggot-fly lays its eggs also on the stem just above or even below the ground, 

 and the larvae burrow into the roots. Cauliflowers as well as cabbages 

 are attacked, and often tens of thousands of acres of these two vegetables 

 are destroyed in a single season by this little fly. The best remedy is the 

 use of cards cut from tarred paper and bound, collar-like, around the stems 

 of the plants. These protecting collars should be put on when the young 

 plants are transplanted from the cold frames into the field. Another familiar 

 member of this subfamily is the little house-fly, Homalomyia canicularis , 

 smaller, paler, and more conical in shape than the true house-fly. 



Every one who has undertaken to rear butterflies and moths from their 

 caterpillars has been compelled to make the acquaintance of certain heavy- 

 bodied bristly flies which appear now and then from a cocoon or chrysalid 

 in place of the expected moth or butterfly. These are Tachina-flies, and in 

 their appearance and parasitic habits are representative of the large sub- 

 family of house-fly cousins known as Tachiniinae. The females fasten their 

 eggs to the skin of young caterpillars, the hatching larvae burrow into the 

 body of their crawling host and feed on its body-tissues Sometimes the 

 caterpillar is killed before it can pupate, but usually not, spinning its cocoon 



