Dec. ii, 1916 
Syntomaspis druparum 
491 
Crab apples, both cultivated and wild, are very frequently infested, 
but invariably to a less extent than the small wild seedlings of the true 
apple, and it is evident that the latter is the natural host of the insect. 
On one occasion the opportunity offered to compare the infestation in 
these two classes of fruit where wild crabs and wild seedlings were found 
growing side by side. Only about 50 per cent of the crabs were infested, 
and rarely more than one seed to the fruit contained larvae, while the 
infestation in the seedling apples was practically 100 per cent, unin¬ 
fested seeds being scarce. 
Although the fruit of the common mountain ash (Sorbus americana) 
has been repeatedly and extensively examined, the writer has never 
found any trace of infestation by this or any other chalcid. 
Neither pears nor the fruit of Crataegus sp. exposed to the attack of 
the chalcid in cages were infested, although attempts at oviposition on 
the latter were repeatedly observed and many fruits were exposed to 
attack and later examined. 
LIFE HISTORY OF THE CHALCID 
The life-history data given below were obtained very largely by propa¬ 
gation of the apple-seed chalcid on wild seedling fruit at North East, Pa., 
and involved the examination of many hundreds of apples. The female 
insects were caged on fruit for one day in cages constructed of mica 
lamp chimneys and cheesecloth (PI. 40, D). 
EMERGENCE IN SPRING 
The insects reared in 1914 were from a lot of apples that had been kept 
in Washington, D. C., during the previous winter and until about May 
15, when they were shipped to North East, Pa. The earlier spring of. 
Washington undoubtedly hastened somewhat the emergence of some of 
the earlier reared adults, for they began to emerge from the seeds on May 
26, which was some time before the apples at North East were at the 
proper stage for oviposition. However, they did not begin to appear in 
numbers until after the middle of June, the heaviest emergence occurring 
during the week of June 22-29 anc ^ the last on July 5. The adults 
reared in 1915 were from apples that passed the winter in an unprotected 
wire cage at North East. The first to emerge appeared on June 16 and 
the last on July 16, with the heaviest emergence, as in 1914, during about 
the last week of June. 
There appears to be very little, if any, difference in the time of emerg¬ 
ence of the sexes. In the more normal emergence of 1915 a few males 
appeared before any females, and the few belated individuals that emerged 
after the first few days of July were all females. But during every other 
day of the emergence season some individuals of each sex appeared. 
