952 I. M. Hawuey 
were used in rearing the plum curculio. Johannsen (1911) thinks the 
species is attracted by decaying matter in the soil. Berger (1908) found 
the insect working in cut surfaces of seed potatoes that showed decay. 
Schoene (1916) has often bred the insect on cabbage, and believes the 
species is attracted to that plant by decomposition in parts of it. Black- 
man and Stage (1918) bred the species on a decaying root of larch. 
The insect has been reported also in Europe. It was found on sea 
kale in England, and Ritzema Bos (1890) reported finding the species 
platura (which, as already noted, is a composite of cilicrura and tricho- 
dactyla) on human excrement, on asparagus, on leek (Allium porrum), and 
on shallot (A. ascalonicum). More recently this species has been dis- 
cussed, under the name Chortophila cilicrura, as a pest of rye and corn in 
Silesia (Oberstein, 1916). Kornauth (1916) reports trichodactyla as 
injurious to beans in Moravia. 
' Under field conditions in western New York during the progress of the 
present study, larvae of Hylemyia cilicrura have been found in beans, 
peas, corn, seed potatoes, and alfalfa roots. Baits of decaying materials 
were placed near the laboratory, and later examination showed the fol- 
lowing to contain maggots: cabbage, bean pods, bean vines, grass stems, 
clover roots, and clover stems. Two larvae have been found in mustard 
growing near a bean field, and two flies were bred from larvae taken in 
late summer in the roots of quack grass (Agropyron repens). The species 
has been reared also from pupae found in a pile of rich soil that had been 
taken from beneath decaying stumps. The writer has never bred the 
fly from manure. : 
From these data it may be seen that the list of known hosts is both 
large and varied, including not only healthy and decaying vegetable tissue, 
but also animal tissue. It is probable that this list is far from complete. 
The first flies taken each spring have been found by sweeping old wheat 
fields, and the writer believes that wheat, oats, and possibly other grains, 
may constitute important late-season hosts; but as yet sufficient data 
are not available for proof of this. Mature females of the second brood, 
taken in July, were numerous near sod and quack grass, and these 
also may be common winter hosts of the insects. 
NATURE OF INJURY TO BEANS 
The larvae of the seed-corn maggot may feed on three parts of a bean 
seedling—the plumule, the cotyledons, and the radicle. The injury to each 
part of the plant is here discussed separately. 
Injury to the plumule 
When the small larva locates a source of food in a sprouting bean, it 
usually crawls between the cotyledons, or seed leaves, and feeds on the 
two leaflets of the plumule and on the small bud of the growing tip between 
