970 I: M. Haw tery 
carabid beetles. No dead flies were seen in the field outside of the pans, 
and later, when the beans came up, there was no reduction in the number 
of snakeheads near the pans. Pans were placed in other fields, and, tho 
many flies were captured, no great benefit was noticeable when the beans 
were examined two weeks later. 
Before planting was done in this field, which was very wet, the seed was 
drenched with kerosene. Eight days after planting, the counts showed 
49 maggot-infested seeds out of 110 that were examined. When the seed 
was treated overnight with carbon disulfid, 17 out of 57 beans contained 
larvae of H. cilicrura. A check had 28 infested seeds in 50. Altho 
neither material injured the germination of the seed, there was little if any 
repellent effect produced. 
Beans were treated also with arsenate of lead in the form of a strong 
paste. This was allowed to dry and the seed was then placed in the 
ground with a bean planter. The poison so injured the seed that only 
about 15 per cent germinated. A check showed an 85-per-cent stand. 
Neither seed treatment nor other artificial control measures have given 
promise of success. No satisfactory material has been found, and nothing 
that looks promising for tests on a large scale has been discovered. 
Natural and cultural methods of control 
There are many factors bearing on the presence or the absence of 
Hylemyta cilicrura in a field. Some of these are discussed in the following 
pages, and practices which are in the nature of preventives are pointed out. 
Moisture and temperature as factors in the life of the seed-corn maggot 
Hylemyia cilicrura has been found to be a serious pest in. New York 
when the early summer is rainy. This increased injury in moist seasons 
is apparently due to the tendency of the cultivated hosts to decay in the 
wet soil, thus becoming attractive to the flies as a place for oviposition. It 
seems probable, also, that maggots already in the soil feeding on other 
decaying vegetation, are attracted to the beans when they begin to 
decay. 
In June of 1916 and also of 1917, the rainfall far exceeded the normal. 
In 1917 the June rainfall (6.4 inches) was more than twice the monthly 
average for the previous twenty years, and the damage from H. cilicrura 
was severe 1n all the bean-growing sections of the State. July of that year 
was rainy also, and thruout that month flies could be taken easily, altho 
normally they are scarce at that season. The years 1918, 1919, and 1920 
were nearly normal, and the loss was slight. In table 6 are given data 
from the United States Weather Bureau at Rochester, New York. 
In periods of drought such as prevailed at Perry during July and August 
of 1918, flies are difficult to find. By July 22, 1918, only six flies of many 
hundreds were still alive in the cages, and on the following day not a fly 
