Weevils in Beans and Peas. 35 
but four strands to the inch (such as shown in Fig. 28) are no protec- 
tion to the seeds within the sacks and do not prevent weevils develop- 
ing in the sacks from crawling out and migrating to and laying their 
eges upon seeds in other sacks of similar weave. But seeds sacked in 
heavy cotton sacks of close weave with 24 strands to the inch are ap- 
parently perfectly protected from infestation from without (Fig. 
29). Some such sacks contained badly damaged and heating seed 
but the infestation was held within them and prevented from spread- 
ing to adjoining sacks by the tightness of the sacks. The common 
bean weevil, the cowpea weevil, and the four-spotted bean weevil can 
eat holes in paper sacks and escape, but do not eat through cloth. 
There is a great deal in favor of a tight cloth sack, not only for 
protecting uninfested seeds from infestation from outside sources 
but also in preventing infestations from spreading. 
O 
