216 THE PEANUT— THE UNPREDICTABLE LEGUME 



pounds without dusting. The peanuts were harvested before much loss 

 from shedding in the ground had occurred. Loss in the ground was re- 

 duced by dusting even after the plants were 90 percent defoliated. 

 Unpublished data (7) indicated effective control of velvetbean caterpillar 

 with cryolite, 10 percent toxaphene, 2 percent DDT, 1 percent gamma 

 BHC, 5 percent methoxychlor, 5 percent DDD, and 1 percent parathion 

 each at the rate of 25 pounds per acre. Five percent chlordane was less 

 effective. 



Cryolite at the rate of 20 pounds per acre is the standard recom- 

 mendation for control of velvetbean caterpillar on peanuts near harvest. 

 It is effective and does not injure the foliage. There is no serious residue 

 problem. DDT is highly effective at rates as low as 0.36 pound technical 

 material (18 pounds 2 percent dust) per acre (161). It is cheaper and 

 faster acting than cryolite. Residue studies, however, have shown that 

 DDT persists on the peanut foliage which is used as hay. The DDT 

 residue on 13 samples of hay collected in Alabama in 1946 varied from 

 2 to 31 p.p.m., depending upon the interval between dusting and harvest 

 and the rainfall during the period (6). All samples of hay containing less 

 than 7 p.p.m. were from fields on which approximately 6 inches of rain 

 fell over the 4- to 5-week period between dusting and harvest. In practice, 

 peanuts are sometimes harvested within 10 days after dusting. When the 

 DDT-treated hay is fed to livestock, the DDT is stored in the fat and 

 passed in the milk of the animals. Thus, it is ultimately passed on to 

 human beings where it is a possible health hazard, especially to young 

 children consuming large quantities of milk. For these reasons cryolite 

 is generally recommended in preference to DDT for velvetbean caterpillar 

 control on peanuts near harvest. 



In 1949, Wilson and Arant reported ( 160) that four applications of 

 2.5 percent DDT applied during the summer months for leafhopper 

 control usually control velvetbean caterpillar throughout the season. The 

 last application made approximately 30 days before harvest does not create 

 a serious residue problem. Where dusting is necessary within 30 days of 

 harvest, cryolife or 5 percent methoxychlor is recommended. 



Fall Armyworm J 



Importance. The fall armyworm, Laphygma frugiperda (A. & S.), is 

 a periodic pest of peanuts in Alabama, Florida and Georgia. Some 

 damage occurs each season in these States, and not infrequently the insect 

 is present in sufficient numbers to cause complete defoliation of peanuts. 



Few references to fall armyworm damage to peanuts are found in 



