Weevils in Beans and Peas. 91 
tion each year and can not start new generations in dried seed in 
storage. That is, such beetles as emerge from the seeds in storage 
have developed exclusively from eggs laid in the field upon the green 
pods and can do no further injury in warehouses. 
WHY WEEVILS LIMIT ACREAGE PLANTED TO CERTAIN 
LEGUMINOUS FOOD CROPS. 
It has been pointed out already that infestation nearly always 
takes place in the field while the crop is maturing. With garden or 
Canada peas, lentils, and broad or Windsor beans infested with the 
pea weevil, the lentil weevil, and the broad-bean weevil, respectively, 
this is always the case, for these weevils never breed in dried seeds. 
Other species that breed in dried seeds, as well as in the field, may 
spread in storage to uninfested seeds and badly infest them. It is 
generally known that the colder the winters the shorter the growing 
season and the fewer the bean and pea weevils that survive the 
cold of winter and are ready to fly to the fields to start the infesta- | 
tion of the growing crop by laying eggs upon the pods. The farther | 
south one goes the more mild the winters become, the longer the} 
growing season, and the greater number of weevils that can live} 
through the winter. 
As far south as the District of Columbia and the adjacent tide- 
water country of adjoining States, therefore, overwintering weevils 
attack the beans and peas in large numbers and succeed in years 
favorable for them in laying so many eggs upon the pods that each 
developing bean becomes affected and often may support as many as 
20 to 28 weevil grubs. Because of the long, warm falls and the 
length of time the plants are allowed to remain in the field after the 
crop has ripened, either standing in the ground or pulled and stacked, 
these grubs are given every opportunity to develop into adults or. at 
least to become very well grown in an unusually large number of 
cases, and therefore they cause greater damage than do weevils in 
bean fields farther north. Thus beans grown in latitudes south 
of New York City, except in higher altitudes, as in the mountainous 
regions of the Alleghenies, become more infested than those grown 
_ north of that latitude. As weevils in beans are not killed so easily 
as are many other insects, and as their presence in numbers in beans 
is objectionable whether beans are grown for food or for planting, 
even when the grubs have been killed (see Fig. 22), the growing of 
beans on a commercial scale for dried seeds has largely been given 
up in our more southern latitudes. This explains the question often 
asked why beans and peas grown in portions of California, Michigan, 
New York, Washington, Oregon, or Idaho, or even in Canada, find 
their way into our southern markets, which one would expect should 
