512 FORAGE PLANTS AND THEIR CULTURE 



or on the seeds when in storage. The greatest amount of 

 damage is done when the peas are in storage. Each female 

 lays as a rule 1 egg on a seed, but this does not deter other 

 females from doing the same. The larva upon hatching 

 burrows into the seed, if necessary first penetrating the 

 pod. Under very favorable conditions the whole life 

 cycle from egg to adult may take place in 18 days, but 

 under ordinary conditions 30 days or more is required. 

 Under indoor conditions at Washington, D.C., 6 or 7 

 broods occur in a year. This rapid reproduction continues 

 until all the peas are practically all destroyed. 



Fumigation by carbon bisulfide is probably the best 

 method of destroying the weevils in stored seeds. The 

 seeds are put in an airtight bin or other receptacle and 

 fumigated 48 hours, using 2 to 3 pounds of carbon bisul- 

 fide for each 1000 cubic feet of space. The bisulfide 

 is poured in shallow pans or dishes on top of the seed, and 

 as the gas volatilizes, it sinks between the seeds, as it is 

 heavier than air. When the fumigation is complete, 

 the seed should be thoroughly aired, as otherwise the 

 germination may be affected. 



