December, ’24] larson and fisher: weevils in dry beans 
633 
are only small quantities, they are not marketed but are stored to be 
used for seed the next year or to be mixed with the new crop and sold. 
Bean screenings and other small lots of beans may also be kept over the 
summer in some of the out-buildings about the farm. These beans fre¬ 
quently become weevily and are overlooked until they are practically 
ruined. Even in large commercial bean warehouses lots of weevil in¬ 
fested beans are held during the summer. Such infested seeds furnish 
the chief source of weevil infestation for the growing crop. They not 
only become unmarketable but they furnish material in which weevils 
are able to continue their development throughout the summer. 
In order to determine the potential possibilities for infesting a new 
crop, by securing information bearing on the approximate number of 
weevils which may emerge in storage and the time these weevils would 
fly from storage in search of new beans upon which to oviposit, as well as 
the duration of such infestations under conditions comparable to those 
obtaining in barns or other out-buildings on farms of Southern Cali¬ 
fornia, the writers infested a part of a bag of black-eyed cowpeas with the 
four-spotted cowpea weevil, Bruchus quadrimaculatus . 
On July 13, 1923, 25 pairs of B. quadrimaculatus were placed in an 
ordinary bean sack containing 69 pounds of “choice recleaned” black- 
eyed cowpeas. The bag was placed on a table inside of an insect cage 
built for this purpose. The cage was 8x6 feet and 6 feet high with a 
narrow door in one end. The top was covered with muslin. An IS 
inch strip of 16 mesh wire screen was placed around the entire upper and 
lower part of the cage; a 38-inch strip of muslin placed around the middle 
of the cage allowing an inch to lap over the upper and lower wire strips 
completed the covering. The screen wire and cloth were fastened se¬ 
curely with cleats at the edges. The door was covered with screen. 
This cage was thought to furnish conditions quite similar to those in 
many of the out-buildings and sheds in which left over bags of beans are 
stored in California. The out-door temperature was recorded in a 
screened insectary adjoining the cage on the south side; the daily means 
are recorded in Chart I. During the summer a piece of compo board 
was laid over the sack but later a window was put over it to keep off the 
rain. 
Throughout the experiment the weevils were counted as they were 
caught in small glass vials containing kerosene. Weevils at large in the 
cage were recorded daily for the most part. It will be appreciated that 
the date of capture indicates only the time when the weevils left the 
