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Weevils in Beans and Peas. 35 
and his neighbors are willing to get together and pledge to treat 
their seeds in storage.. Many adult weevils fly to fields from storage, 
or remain in fields harvested in a slack manner. A negligent neighbor 
may be the cause of much neighborhood infestation by the flying of 
his weevils to developing crops or into warehouses. 
Community effort to reduce weevil losses can be made effective in 
localities where beans and peas are grown on a commercial scale. It 
is doubtful if concerted action can be secured in towns or cities where 
there are many small gardens yielding but a few seeds, for these small 
quantities of seed are of too little value to move their owners to ac- 
tion. The University of California during 1918-1920 conducted a 
campaign of community effort, in San Mateo County, Calif., directed 
against the broad-bean weevil (p. 19) and found that by working 
through the county agent and fumigating the crops after they were 
placed in storage the infestation in the field was reduced from 43 
per cent in 1918 to 21 per cent in 1919 and to 17.8 per cent in 1920. 
The county agricultural agent has here a worth-while field for action 
along with his many others. To succeed, all farmers in a district 
should treat their seeds and destroy promptly refuse from cleaning 
machines. 
TREATMENT DOES NOT PREVENT REINFESTATION. 
Treatment of legumes subject to infestation by weevils that can 
breed generation after generation in storage will not keep them free 
from weevils if they are stored so that adult weevils can get to them 
and lay eggs on them. The application of remedial measures may 
kill all weevils in the seed at the time of treatment, but it should be 
remembered that no treatment has a lasting effect in preventing rein- 
festation from outside sources. Seeds once treated should be stored 
in rooms free from adult weevils, or placed in tight barrels or sacks 
made of closely woven material, and should be examined occasionally 
as a guard against subsequent infestation. 
When large quantities of seeds are brought together under one 
roof, they usually represent the crops of many farmers whose local 
conditions may have varied to such an extent that one carload lot of 
seed may be free of infestation while the next may be slightly or 
heavily infested. Experimental work has proved that sacking seeds 
in one thickness of hght-weight close-weave muslin will prevent un- 
infested seed from becoming infested- even though there are many 
weevils and weevilly seeds close by. It is not practical in large seed 
warehouses to use sacks of light-weight muslin, yet a study in 1917- 
18 of conditions in large warehouses containing many carload lots 
of seed indicates the value of closely woven sacks. Jute sacks with 
