238 
Journal of Agricultural Research 
Vol. II, No. 3 
starting of the experiment to the death of the last boll weevil. The 
longevity was surprisingly great, only one boll weevil dying in less than 
24 days, and the average for both sexes being 25.3 days, with a maximum 
of 40 days. It is evident that the blooms are better food than the buds. 
The longevity of the bloom-fed boll weevils is much greater than of those 
fed either on cotton bolls or leaves and compares well with the longevity 
on squares. 
The pollen is the first choice of the boll weevils. One weevil will soon 
destroy every anther in a large bloom and usually emerges covered with 
pollen. However, in practically every case there is more or less feeding 
on the corolla itself. This frequently takes the form of large areas eaten 
from a beginning on the margin of a petal, but often the petal is merely 
riddled with small holes. 
By far the greatest number of experiments on feeding Hibiscus syriacus 
were series where buds, blooms, and young fruit were offered to the boll 
weevils every day. 
Some boll weevils were reared in the laboratory and placed on Hibiscus 
immediately after emergence, while others were collected in the field and 
consequently had fed first on cotton. 
Three lots of boll weevils collected in the field—12 in all—were used. 
In two lots they were collected in the field, brought to the laboratory, 
and were immediately placed in tumblers with a base of moist sand and 
containing fresh buds, blooms, and young fruit of Hibiscus syriacus . In 
the other lot, hibernated individuals that had been collected some days 
previously and fed on cotton squares until the time of starting the exper¬ 
iment were used in the same manner. The four pairs collected in the 
field were in copulation at the time of capture. When possible, the food 
was changed often enough to give a constant supply of fresh buds, 
blooms, and young fruit. 
The boll weevils all began feeding immediately after being placed with 
the Hibiscus. In a total of 53 examinations feeding was found in all but 
2 cases. Both of these were found toward the last of a series when only 
one boll weevil remained, affording striking evidence of the readiness 
with which they fed on Hibiscus even when accustomed to cotton. 
An analysis of feeding by the parts of the plant attacked gives the 
following: Corolla, 40 times; stamens, 40 times; buds, 14 times; and 
young fruit, 6 times. This shows the very decided preference for the 
bloom. 
Although the females used in two series were in copulation when col¬ 
lected in the field, only one egg was secured during the experiment. 
This egg was deposited normally in a bud 31 days after the female had 
been placed on Hibiscus. It hatched, and the larva lived until about 
half grown. During its life it consumed much of the tissue of the bud. 
The maximum longevity was 36 days, the average being 16 days. 
While this longevity is short when compared with that on cotton, it cer¬ 
tainly shows that it is possible for the boll weevil accustomed to feeding 
on cotton to subsist for a long time on Hibiscus. 
Three series of boll weevils reared in the laboratory were used in 
another experiment—one lot in the spring, one in summer, and one in 
the fall. In all of these experiments the boll weevils were reared on 
cotton bolls or squares in the laboratory. They were then placed imme¬ 
diately in tumblers containing a layer of moist sand and offered a mixture 
of buds, blooms, and young fruit every day until the supply of food was 
exhausted. 
