mated in the fall and in the fall and spring. 

 Jour. Econ. Ent. 56: 180-181. 1963. 



Oviposition capabilities, viability of eggs 

 produced, amount of feeding, and longevity 

 were determined. From 8 to 20 percent of fe- 

 male weevils were incapable of producing eggs. 

 Females not allowed to remate in the spring 

 produced about 50 percent fewer eggs than 

 those that remated, but the oviposition and pre- 

 oviposition periods were not significantly 

 different. Among groups of weevils that 

 emerged normally there was no difference in 

 longevity between females remated in the 

 spring and those mated only the previous fall. 



168. Taft, H. M., and Jernigan, C. E. Ele- 

 vated screens for collecting boll weevils flying 

 between hibernation sites and cottonfields. 

 Jour. Econ. Ent. 57: 773-775. 1964. 



The equipment was designed for comparing 

 flight movements of boll weevils leaving hiber- 

 nation sites in the spring and those leaving a 

 cottonfield to enter hibernation sites in the fall. 

 Weevils flew out of the cottonfields at greater 

 altitudes than out of the hibernation sites. The 

 equipment could be used for studies of other 

 flying insects. 



169. Thomas, J. G., and Brazzel, J. R. A 

 comparative study of certain biological phe- 

 nomena of a resistant and a susceptible strain 

 of the boll weevil, Anthonomus grandis. Jour. 

 Econ. Ent. 54: 417-420. 1961. 



An increase of 12.5 hours in the develop- 

 mental period of the resistant strain over the 

 susceptible strain and a 22 percent decrease in 

 the fecundity of the resistant females were the 

 most significant biological differences observed. 

 No differences were observed in mortality rates, 

 sex ratios, length of preoviposition and ovi- 

 position periods, or percentage egg hatch. 



170. Tippins, H. H., and Beckham, C. M. 

 Variations in susceptibility to endrin of four 

 boll weevil populations. Ga. Agr. Res. 3(1): 

 4-5. 1961. 



The toxicity of endrin to 2-day-old boll wee- 

 vils reared from cotton squares collected peri- 

 odically from single fields in four counties in 

 Georgia was determined during 1960. The wee- 

 vils from Gordon County were highly suscepti- 

 ble to endrin. Weevils from Early and Sumter 

 Counties exhibited resistance to endrin. Those 

 from Pike County were intermediate in reac- 

 tion to this insecticide. This is not interpreted, 

 however, as meaning that all weevils in the 

 three counties are resistant to endrin. The data 

 apply only to the weevil populations in the par- 

 ticular fields sampled. Additional studies are 

 needed to delimit the areas of resistance. 



171. Tippins, H. H., and Beckham, C. M. 

 Boll weevil resistance to several chlorinated 

 hydrocarbon insecticides in Georgia. Jour. 

 Econ. Ent. 55: 944-947. 1962. 



Studies were conducted in the laboratory on 

 weevils collected in 16 counties in Georgia. Only 



those weevils from extreme northern counties 

 were highly susceptible to endrin. There was 

 some indication of reversion to susceptibility 

 to endrin in 1959 and 1960. However, little or 

 no difference was found in the susceptibility 

 of weevils after a change in field applications 

 from chlorinated hydrocarbon to organic phos- 

 phate insecticides during 1961. Resistance to 

 BHC and toxaphene was established. Two years' 

 results showed field-collected weevils of un- 

 known age to be 50 to 210 times harder to kill 

 than 2-day-old square-reared weevils. 



172. Vanderzant, E. S. Nutrition of the 

 adult boll weevil: Oviposition on defined diets 

 and amino acid requirements. Jour. Insect 

 Physiol. 9: 683-691. 1963. 



Boll weevil adults were fed and oviposited 

 on defined diets consisting of casein, amino 

 acids, sugars, corn oil, cholesterol, inositol, cho- 

 line, mineral salts, B-vitamins, agar, and water. 

 No extractives of the cotton plant were needed 

 to induce egg laying. Good oviposition also was 

 obtained in protein-free diets in which amino 

 acids and dextrin were substituted for casein. 

 No eggs were obtained when arginine, histi- 

 dine, isoleucine, leucine, lysine, threonine, tryp- 

 tophan, valine, methionine, or phenylalanine 

 were omitted one at a time from the diet. Eggs 

 were laid by females fed diets containing the 

 10 indispensable amino acids, glutamic acid, 

 and glycine as the only sources of nitrogen for 

 protein formation. 



173. Vanderzant, E. S. Nutrition of the 

 boll weevil larva. Jour. Econ. Ent. 56: 357- 

 362. 1963. 



Dietary requirements of larvae reared on a 

 purified casein diet are reported. 



Compounds of myo-inositol are just as ef- 

 fective in promoting growth as free inositol. 

 Choline is needed and cannot be replaced by 

 betaine, carnitine, or ethanolamine. Dietary fat 

 improves development of the larvae and per- 

 mits more larvae to become adults. Sterols are 

 indispensable for growth; cholesterol, stigmas- 

 terol, and sitosterol can all be used. 



Six B-vitamins found to be needed in casein 

 diets are pantothenic acid, thiamine, riboflavin, 

 pyridoxine, niacinamide, and folic acid. Biotin 

 was not required. In tests performed, antime- 

 tabolites of thiamine, biotin, and pantothenic 

 acid did not interfere with growth. 



Sodium alginate, used in previous diets as a 

 stabilizer, was found to inhibit growth. 



174. Vanderzant, E. S. Axenic rearing of 

 the boll weevil on defined diets: amino acid, 

 carbohydrate, and mineral requirements. 

 Jour. Insect Physiol. 11: 659-670. 1965. 



Boll weevils were reared from egg to adult 

 on defined diets composed of amino acids, sug- 

 ars, fatty acids, cholesterol, choline, inositol, 

 B vitamins, mineral salts, agar, and water. 

 Yields and weights of adults and their rates of 

 development were similar to those obtained 



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