THE CHALCIS-FLY IN ALFALFA SEED, 9 
ment, emerge from the seeds, and deposit their eggs into the green 
pods growing on the same plant upon which they themselves were 
fostered. 
in view of this the seed crop should be so handled that the setting 
of pods will be as uniform as possible, and the crop should then be 
harvested as soon as the larger number of the pods are ripe. 
STACKING THE SEED CROP. 
It has been demonstrated that great numbers of chalcis-flies emerge 
from the seed pods at about the time the pods ripen, and continue to 
emerge indefinitely. In midsummer most of them, however, emerge 
Fig. 9.—An alfalfa seed field with check ridges and fence lines burned over to destroy the hibernating 
larv:e of the chalcis-fly. (Original.) 
within three or four weeks after the crop is harvested. Where later 
seed crops are grown, it is therefore advisable to stack the early crops 
as soon as possible, thus preventing the free emergence offered by 
leaving the crop in shocks on the field. 
DESTROYING BUR CLOVER. 
In some localities bur clover grows abundantly and matures its 
seed pods in early spring. The chalcis-flies thus have already com- 
pleted the development of an entire generation in the seeds of these 
plants before the alfalfa seed pods have developed in the fields. 
Under such conditions it would be well to destroy the bur clover pods 
by burning the fence lines in the spring. This can frequently be done 
after the plants mature and before the alfalfa seed crop comes on. 
CLEANING THE SEEDS. 
Some of the alfalfa seed-growing districts have organizations 
among the seed growers with officers having complete charge of clean- 
ing and marketing the seeds for the growers. The product handled 
