aid in the control of many destructive insects such as aphids, 
scales, psyllids, spittlebugs, mealybugs, and lepidopterous larvae. 
A few species are plant feeders but they are seldom injurious. 
Adults are usually brightly colored and are frequently striped, 
spotted, or banded with yellow. Some resemble wasps; others look 
like small bumblebees. The males have the peculiar habit of 
hovering almost completely motionless in the air and then darting 
swiftly to one side when disturbed. The maggots of insect feeding 
species are sluglike. The body tapers toward the front end and 
the body contents are visible through the integument. Wirth, 
Sedman, and Weems (787) published a list of the syrphids occur- 
ring in America north of Mexico. 
FAMILY CONOPIDAE 
THICK-HEADED FLIES 
Conopid flies are thinly pilose or nearly bare, elongate, and of 
moderate size. The head is broader than the thorax, and the 
abdomen is elongated and constricted. The antennae are 3-seg- 
mented, the third segment bearing a dorsal arista. Adults fly 
slowly and are usually seen around flowers. The larvae are soli- 
tary internal parasites, mainly of Hymenoptera. One species 
parasitizes grasshoppers and crickets. 
FAMILY TEPHRITIDAE 
FRUIT FLIES 
Fruit flies are fairly small and usually have spotted or banded 
wings. The larvae are usually pale yellowish and taper slightly 
toward the front. Eggs of most species are deposited in healthy, 
living tissue and the larvae feed in various parts of plants. Cer- 
tain species produce root and stem galls and a few are leaf 
miners. Others develop in fleshy fruits or in the seeds or ovaries 
of flowers. Many species are highly destructive of fleshy fruits 
and vegetables throughout the world. A few of the species occur- 
ring in the woodlands or forests of eastern United States are 
discussed below. 
The apple maggot, Rhagoletis pomonella (Walsh), an important 
pest of apple, also breeds in the fruit of hawthorn, choke cherry, 
plum, and dogwood. The adult is dark colored and a little smaller 
than the house fly. Each wing is crossed by four dark bars which 
merge together. Three or four white bands run across the dorsum 
of the abdomen. The cherry fruit fly, R. cingulata (Loew), breeds 
in the fruit of wild cherry. Adults are black except for yellow 
margins on the thorax, two white cross bands on the abdomen, 
and a dark band on each wing. They are smaller than house flies. 
The black cherry fruit fly, R. fausta (O. S.), breeds in wild cherry 
throughout the same area as does the cherry fruit fly. Adults 
resemble those of the cherry fruit fly except for the abdomen 
which is entirely black. The walnut husk fly, R. completa Cresson, 
breeds in the husks of black walnut in the Central States. Feeding 
424 
