632 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
and Anapkoidea luna; the larval parasites, Bathyplectes curculionis , 
Bathyplectes corvina, and Tetrastichus incertus; and the prepupal and 
pupal parasites, Dibrachoides dynastes and Necremnus leucarthros. 
With the exception of Anapkoidea luna , all these parasites were shown 
to be able to live under a rather large range of climatic conditions. In 
view of this fact, it seems probable that most of them could survive a 
climate like that of Utah, and leaving out of consideration the possible 
need of undiscovered alternate hosts for some of them to complete their 
life cycle, it seems practicable to colonize all of them. There is a con¬ 
siderable difference in the extent of parasitism by these species in differ¬ 
ent seasons and sections, and in different fields in the same section, 
doubtless owing in part to the effect of climate, cultural systems, and 
disease upon the numbers of the host. Neither cultural systems nor 
diseases appear to check the alfalfa weevil in the United vStates to as 
great an extent as in Europe. The greater numbers of weevils present, 
therefore, may afford a better opportunity for the work and multipli¬ 
cation of parasites and increase their effectiveness, as seems to have 
been the case with Bathyplectes curculionis. 
THE POSSIBILITIES OF WEEVIL DEVELOPMENT IN 
NEGLECTED SEEDS IN WAREHOUSES* 
By A. O. Larson, Associate Entomologist, and C. K. Fisher, Junior Entomologist, 
Stored Product Insect Inevstigations, Bureau of Entomology, 
U. S. Department of Agriculture 
Abstract 
Bean growers as well as commercial bean warehouses usually keep lots of beans 
and cowpeas over the summer. Such lots of seeds furnish ideal breeding places for 
the common bean weevil, Bruchus obtectus, and for the four-spotted cowpea weevil, 
B. quadrimaculatus. They frequently become weevily and furnish the chief source 
of weevil infestation for the growing crop. Heavy infestations in the field have been 
traced directly to small lots of weevily seeds. 
The experiments here recorded show that several broods of weevils may develop 
in a small lot of seeds. Most of the weevils fly away in search of new material on 
which to oviposit, but enough remain among the original seeds to keep up the 
infestation until practically all the available food has been removed. Sixty-nine 
pounds of black-eyed cowpeas produced approximately 368,000 emerged weevils or 
4p2 adults for each seed, and were reduced 62 per cent in weight. 
Bean growers frequently have small lots of beans of one or more 
varieties left over after the spring planting is completed. Because they 
*In this article any storehouse about the farm is considered a warehouse as well 
as all commercial bean warehouses. 
