974 I. M. Hawiey 
before or after these dates. Since the larvae already in the soil may 
attack the newly planted seed, it is wise to delay planting for a few days 
after all the eggs have been deposited. This would extend the time for 
probable infestation in 1919 and 1920 from May 28 to about June 15. 
Unfortunately, it is not always possible to choose the time of planting as 
suggested above. Weather conditions may prevent planting in May, 
before the flies are mature, and if beans are put in too late in June they 
may not ripen before they are killed by frost. Seasons vary so much from 
year to year that no absolute rule can be given; but, if weather permits, 
it is best to plant before the oviposition period of the flies, when the last 
of the petals have fallen from late apple trees. 
Relation of kind and condition of soil to maggot infestation 
Abundant moisture provides favorable conditions for the development 
of Hylemyza cilicrura, as is shown on page 970. Beans on heavy soil, 
which holds moisture, grow more slowly, decay, and furnish conditions 
attractive to the flies for oviposition. In 1917 one side of a bean field 
near Perry was badly infested, while the remainder, which was planted on 
the same day, was free from injury. An examination of the soil in the 
infested part showed it to be heavy and sticky, while the unattacked beans 
were growing in lighter soil of a sandy constituency, which was relatively 
dry. The division between the two types of soil was very marked, and the 
good and the poor beans followed this line closely. Well-drained fields 
are not attacked as often as are those where the drainage is poor. Low 
and wet spots, where water may collect in otherwise good fields, often 
yield poor beans. ‘This is in part the result of maggot work, but it may 
often be due to the decay caused by the excess of moisture in the soil. 
Warm, dry soil that is well fitted furnishes ideal conditions for the 
growth of beans. In soil of this kind they will germinate quickly, and when 
once above ground there is little chance of serious injury from maggots. 
In wet seasons it is best to delay planting until the soil can be well fitted. 
A field should be dragged and rolled, and the top layer of earth allowed to 
dry out and become warmed by the sun. 
Influence of preceding crop and time of fitting a field, on maggot attack 
Heavy infestations of Hylemyia cilicrura have been found on land that 
had previously been in potatoes, corn, tomatoes, wheat, oats, and beans, 
as well as in clover and alfalfa sod. Many infestations have followed sod, 
since the upturned roots of decaying clover and alfalfa furnish good breed- 
ing condifions for maggots, and since clover forms a part of a regular 
rotation of beans, wheat, and clover which is practiced in western New 
York. Just as serious outbreaks have been found, however, where the 
preceding crop was beans, especially if the field had an. abundance of 
quack grass and weeds. In the writer’s garden there was a patch of 
quack grass. This was turned under, and beans and peas planted on 
