2 weeks. Exposure of eggs to 600 r did not 

 affect hatch or subsequent development; 

 whereas, 2,400 r drastically reduced hatch and 

 prevented subsequent development. 



51. Davich. T. B., Lindquist, D. A., and 

 Hacskaylo, J. Implanting boll weevil eggs in 

 cotton squares for systemic insecticide and 

 host-plant-resistance studies. Jour. Econ. Ent. 

 58: 366-368. 1965. 



A simple technique involving infestation of 

 cotton squares with eggs of the boll weevil can 

 be used in systemic insecticide and host-plant- 

 resistance studies against the larvae. Adult 

 weevil yields from implanted eggs averaged 

 57.9 percent and 76.9 percent in two tests. 

 Adult yields were generally higher from 

 squares remaining on plants from 3 to 7 days 

 and measuring 9.1 to 13.0 mm. long. 



52. Davis, J. W., Cowan, C. B., Jr., and 

 Parencia, C. R., Jr. Field experiments with 

 insecticides on cotton for control of the boll 

 weevil, bollworm, and cotton leafworm in 1961. 

 Jour. Econ. Ent. 55: 688-692. 1962. 



Stauffer R-1504 compared favorably in con- 

 trol of the boll weevil with Sevin or Guthion. 

 Geigy 30494, Methyl Trithion, and Bayer 41831 

 were as effective as methyl parathion. In two 

 experiments endrin plus DDT gave control 

 equal to that obtained with toxaphene plus 

 DDT but not equal to that obtained with Sevin 

 or Guthion. Dusts or sprays of toxaphene plus 

 DDT and Strobane plus DDT were equally ef- 

 fective against boll weevils and bollworms, but 

 were less effective than Guthion plus DDT 

 against boll weevils. Results are given of tests 

 against bollworms and cotton leafworms. 



53. Davis, J. W., Parencia, C. R., Jr., and 

 Cowan, C. B., Jr. Field experiments for con- 

 trol of thrips, cotton fleahoppers, and over- 

 wintered boll weevils in 1960. Jour. Econ. 

 Ent. 54: 966-970. 1961. 



Good kills of overwintered boll weevils were 

 obtained with Shell Compounds SD-5539 and 

 SD-5533, Geigv 30494, Methyl Trithion, and 

 Bayer 29493. Bayer 30911 was ineffective. 

 American Cyanamid Anti-feeding Compound 

 24055 was ineffective against thrips, the cotton 

 leafhopper, and overwintered boll weevils. 



54. Dunn, H. A., Compiler. Cotton boll wee- 

 vil (Anthonomus grandis, Boh.) abstracts of 

 research publications, 1843-1960. U.S. Dept. 

 Agr. Misc. Pub. 985, 194 pp. 1964. 



An annotated bibliography. 



55. Earle, N. W., and Newsom, L. D. Ini- 

 tiation of diapause in the boll weevil. Jour. 

 Insect Physiol. 10: 131-139. 1964. 



It was found that diapause could be induced 

 by 11-hour and suppressed by 13-hour photo- 

 periods. The immature stages were sensitive to 

 photoperiod. Adults were not. Response to pho- 

 toperiod was modified by temperature and food, 

 but maturity of the host plant had little or no 



effect. Ability to diapause differed in strains 

 of different geographical origin. 



56. Earle, N. W., Walker, A. B., Burks, 

 M. L. Storage and excretion of steroids in the 

 adult boll weevil. Compar. Biochem. and Phys- 

 iol. 16: 277-288. 1965. 



Anthonomus grandis required about 20 mg. 

 of cholesterol per 100 g. of diet for sustained 

 egg production and normal longevity. Nutri- 

 tional and radiotracer experiments indicated a 

 high rate of replacement of body cholesterol. 

 The mean life span for adult weevils on sterol- 

 deficient diets was 14 days compared with the 

 normal range of 55 to 89 days for controls. 

 Sterol-deficient females laid almost no eggs. 

 Significant amounts of sterol were carried over 

 from the larval to the adult stage. A high per- 

 centage of the cholesterol in newly emerged 

 adults was replaced within 15 days by labeled 

 cholesterol in the diet. Fat weevils contained 

 more sterol esters than lean weevils, but about 

 the same amount of free sterols was found in 

 fat and lean groups. The boll weevil is the only 

 insect in which dietary sterol has been shown 

 to be essential for adult survival. 



57. Enkerlin, S. D. Effectiveness of cal- 

 cium arsenate for control of cotton pests under 

 conditions of Apocado, Nuevo Leon [Mexico]. 

 Agronomia [Monterrey] 96:2-7. Sept. 1964. 

 [In Spanish.] 



Results of field tests for control of Anthono- 

 mus grandis, Alabama argillacea, and Buccu- 

 latrix thurberiella in 1960, 1961, and 1962 

 indicated that calcium arsenate was more effec- 

 tive than the six other insecticides tested. 



58. Enkerlin, S. D., and Fernandez, F. 

 The effect of calcium arsenate against the cot- 

 ton boll weevil Anthonomus grandis (Bohe- 

 man) and other cotton pests. Folia Ent. Mex. 

 5:3-20. 1964. [In Spanish.] 



During 3 consecutive years eight different 

 insecticides were used at the rate of 15 kg. 

 dust/ha. ; in each ha. 30,000 cotton plants were 

 planted. The effect of calcium arsenate was 

 compared with other insecticides in common 

 use in cotton pest control. The 3-year average 

 shows that treatment with calcium arsenate 

 gave better results than that with other insec- 

 ticides; BHC was the least successful. The ap- 

 plication of insecticides at the beginning of 

 July is recommended. As to crop yields, hep- 

 tachlor and calcium arsenate gave best results. 

 The maximum economic returns are obtained 

 with calcium arsenate. 



59. Everett, T. R. Feeding and oviposition 

 reaction of boll weevils to cotton, althea, and 

 okra flower buds. Jour. Econ. Ent. 57: 

 165-166. 1964. 



Okra is not a host plant of the boll weevil. 

 Althea is only moderately acceptable. Labora- 

 tory observations suggest the presence of con- 

 stituents in the perianth that are repellent to 



