966 I. M. Hawtiry 
SEASONAL HISTORY 
Adult flies of the first brood are found in the fields from early in May | 
until the middle of June, and deposit their eggs on decaying material or | 
on moist soil about bean-planting time, during the last of May or early | 
in June. The maggots work in beans, corn, potatoes, or rotting vegeta- 
tion, and emerge as second-brood flies in July. These flies soon disappear 
in normal hot, dry summers, but apparently they deposit eggs about | 
decaying vegetable matter before they die. A few third-brood flies may — 
appear in August and September, some of which may hibernate; but most - 
of the flies taken in May of the next year are believed to come from the | 
midsummer brood of pupae which overwinter. 
CONTROL 
Control measures for Hylemyia cilicrura may be classed either as arti- : 
ficial, such as seed treatment and the use of baits, or as cultural. The | 
cultural methods involve studies of influential factors in the environment - 
of the insect, and of practices used in growing the crop which may affect | 
the extent of infestation by the maggots. The artificial methods are 
recorded first. | 
Artificial methods of control 
The studies in artificial control that have been directed against Hylemyza | 
cilicrura in the past have been concerned mainly with seed treatments and | 
with the application to the soil of such materials as would either kill the | 
maggots or act as repellents for the adult flies and thus prevent the depo- 
sition of eggs. Lintner (1882a) suggests soaking the seed in gas tar or > 
copperas to keep the maggots away, and Lugger (1896) says these. 
materials work well on a small scale. Headlee (1913) tried solutions of : 
corrosive sublimate, sulfocide, and potassium cyanide, in an effort to kill” 
the maggots and prevent oviposition by the flies, but his results were 
unsatisfactory. Later (1918) he tells of trying strips of tar, and also of. 
the application of sand treated with carbolic acid to the surface of the 
soil just after beans were planted. As a result of this treatment, a few 
more plants came up in the treated plots than in the checks. Still later” 
(1920), Headlee found that a repellent effect on the maggots resulted from 
treating lima beans with coal tar and dusting them with ashes, lime, or 
tobacco dust. Chittenden (1909) suggests that carbolic acid might act as- 
a repellent to the adult flies, and both he and Bruner (1910) advise the 
application of kainit, nitrate of soda, or sulfate or chloride of potash to 
the soil as a top dressing. In addition to discouraging oviposition, this 
practice is said to have the added advantage of stimulating plant gr owth. | 
While seed treatment and the application of insecticides to the soil may: 
be of value when used in a small way, these practices are of doubtful: 
importance as control measures on a field scale. An infestation of the’ 
