29 
THE COMMON BEAN WEEVIL OS THE COWPEA. 
During- the autumn of 1896, J had frequent occasion to observe the 
beetles of the common bean weevil. Bruchus obtectus Say. upon the 
experimental plats of cowpeas on the grounds of the Department of 
Agriculture. They were evidently engaged in ovipositing oil the 
plants, as specimens were reared later from the seed gathered from the 
held. In October Mr. Pratt found the insect at work in dried cowpeas 
that were on exhibition in the pods in the museum of the Department, 
which adjoins the experimental gardens. 
It has been noticed of this species the past year that it begins to 
issue from beans in the field in the neighborhood of the District of 
Columbia as early as October, when in the natural course of events 
the eggs for a new brood would be deposited in such pods as had 
cracked open so as to expose the seeds within. 
This species breeds in dried peas also, but whether it would attack 
this legume in the field where an abundance of beans were available 
as food remains to be seen. 
It is not a little singular that the same or similar parasites that 
affect the cowpea weevils have never been reared from the common 
bean weevil. 
DEVELOPMENT OF THE COMMON BEAN WEEVIL. 
Our present knowledge of the early literature of Bruchus obtectus 
extends no farther back than the time of Say's description in July of 
1831. The first economic account of the insect is credited to Asa Fitch, 
and appeared just 30 years later. Strangely enough it was not until 
1870 that the species attracted any marked attention. In that year a 
number of accounts appeared, including a half dozen articles and notes 
published in volume II of the American Entomologist. Longer or 
shorter accounts have appeared in great number in succeeding years, but 
in only one that has been seen by the writer was any attention paid to 
the duration of the different stages of the species. In Insect Life Vol. 
V. p. 80) Mr. M. V. Slingerland gave a brief statement of the develop- 
ment of the insect at Ithaca, N. Y., in dried beans, which may be 
summarized as follows: Egg. 12 to 20 days: larva, 24 to 41* days: papa, 
11 to 18 days; entire life cycle. IS to 80 days: the first figure repre- 
senting the period for warm weather, the higher number that for a 
colder period. 
Having spent considerable time in earlier years ;it Ithaca. 1 am able 
to speak from experience of the great difference in the climate where 
these experiments were conducted and that of the District of Columbia. 
To obtain a proper conception of the difference it should be added 
that, in addition to the latitude and elevation of the two places, Cor- 
nell University, where Mr. Slingerland's experiments were made, i< 
located upon a hill upward of 400 feet above the level o\ Cayuga 
