INSECT PESTS 215 



factors influencing abundance, such as climatic conditions, diseases, para- 

 sites and predators. 



Control — Natural enemies and climatic conditions are of value in re- 

 ducing the population of the velvetbean caterpillar but cannot be de- 

 pended upon for control. Douglas (46) reported seven species of birds, a 

 predaceous wasp, a hymempterous parasite, and a parasitic fungus at- 

 tacking the caterpillar. Hinds and Osterberger (73) reported several 

 parasites and predators, including a Tachinid, Winthemia rufopicta 

 Bigot, which parasitized as high as 70 percent of the caterpillars. They 

 also described a parasitic fungus identified (46) as Spicaria prasina 

 (Maulk.) Saw, considered synonymous with Botrytis rileyi observed by 

 Watson (148). Apparently the same fungus, described by Purswell 

 (122), has caused 30 percent fatality to velvetbean caterpillars in fields 

 near Dothan, Alabama. Insect enemies of the velvetbean caterpillar 

 include Sphex pictipennis (Walsh), Solenopsis geminata (F.), Calosoma 

 sayi (Dej.), C. scrutator Fabr., Posidus maculiventris, Proxy s punctu- 

 latus, Stir&trus anchor ago (Fab.), Ephialtes aequalis (Prov.), Ophion 

 bilineatum Say, and Brachymeria ovata (Say). Dry weather also appears 

 to be detrimental to the multiplication of velvetbean caterpillar. 



Insecticidal control of the velvetbean caterpillar on peanuts has been 

 found profitable. Early control practices consisted of applying arsenicals, 

 such as Paris Green, lead arsenate, and calcium arsenate, but consider- 

 able burning of foliage resulted on some crops. Douglas (46) found 

 sodium fluosilicate is highly effective and safe on soybeans. Ellisor and 

 Floyd (51) found cryolite to be somewhat less toxic to velvetbean 

 caterpillar than calcium arsenate and acid lead arsenate, but the degree 

 of toxicity indicated the possibilities of cryolite as a control for the insect. 

 Guyton (65) reported the effective use of lead arsenate on peanuts 

 without injury to foliage. Eddy (48) and Bissell and Alden (16) recom- 

 mended cryolite on peanuts. English (52) found cryolite and 3 percent 

 DDT dusts highly effective. Moderate gains in yield of peanuts resulted 

 from one timely application of these dusts, and where digging was de- 

 layed 10 days fewer peanuts were lost in the soil on the dusted plots 

 than on untreated areas. The retention of the pods by the dusted plants at 

 harvest was especially significant and accounted for most of the benefit 

 - derived from dusting. Cryolite, DDT, and benzene hexachloride have 

 been reported as highly effective (6). DDT protected peanuts over the 

 longest period ; protection given by benzene hexachloride was the short- 

 est. Complete protection from caterpillar damage resulted in gains in 

 yields of 302 to 573 pounds of dry peanuts per acre on land yielding 946 



