976 I. M. Hawtey 
examined on July 19, the beans that were planted about one inch deep | 
were nearly all up, those planted three inches deep were about half thru | 
the soil, and none of those planted five inches deep were yet above ground. — 
In another wet field 100 seeds were planted at depths of one, three, and | 
five inches, on July 16. On July 23 there were, in the one-inch planting, 
57 plants; of which 4 were snakeheads; in the three-inch planting there 
were 35 plants, of which 5 were snakeheads; and none of the beans planted 
five inches deep had appeared above ground. In the laboratory field, under 
rather warm. dry conditions in July, 1918, it was found that beans planted 
three inches deep came up nearly as quickly as those planted more shallow. 
Summary of preventive measures 
The results of experiments on artificial control measures, such as coating 
the seed before planting and treating the soil with materials of a repellent 
nature, afford small hope for their future successful development. As a 
result of a study of some of the factors governing infestations, the possible 
preventive measures that have been discussed in the foregoing pages are 
summarized in the following paragraphs. 
The seed-corn maggot is more serious as a pest when the months of 
May and June are rainy, and the ground is cold and wet at bean-planting 
time, than under other conditions. The greatest injury results when 
several unfavorable years occur in succession. Hylemyza cilicrura thrives 
when oviposition takes place under wet conditions; and therefore it is wise 
to plant when the soil is dry and the earth is warm. The soil should srst 
be well fitted with a disk or a harrow, and then rolled, and finally, after a 
few warm days have dried out the top soil, the beans should be planted. 
if the field is fertilized in order to hasten the germination of the seed, there 
is a still better chance of getting a stand. However, fields fertilized with 
fresh manure just before plowing often show a heavy infestation of mag- 
gots, and so this condition should be guarded against in wet years. 
As maggots developing from eggs deposited on newly tilled ground are 
often found in decaying matter in the soil, it is sometimes wise to fit a 
field early, before most of the flies are sexually mature. The ground will 
then be dried and less attractive to flies for oviposition by the time they 
come out. The presence of many flies of this species crawling over newly 
turned soil between plowing and planting time is a good indication that 
seed planted there will probably be infested. In 1918, 1919, and 1920, 
sexually mature flies were most numerous in the fields at Perry from May 
25 to June 10. In 1919 the greatest number were present about June 4, 
and in 1920 about June 2. If the weather permits, it is better to plant 
ahead of this brood. If this is impossible, planting should be delayed 
until the fltes are less common. 
It is extremely important that beans should not be planted too deep in 
wet soil, If they are, some of the seed will rot and the maggots will destroy 
