I960 - Bass, Max H., and James W. Rawson. Some effects of age, preimaginal habitat, 

 and adult food on susceptibility of boll weevil to certain insecticides,, J. Econ. 

 Ent. 53(4):534-536. 



Experiments were conducted to determine the toxicity of Guthion 

 (0,0 -dimethyl S-(4-oxo- 1,2, 3-benzotriazin- 3-(4H)-ylmethyl) phosphor odithioate), 

 BHC, and toxaphene to the boll weevil under certain conditions of preimaginal 

 habitat, adult food source, and weevil age. There was a 48- and 6l-fold difference 

 in the LD-50 of BHC and toxaphene, respectively, between the easiest to kill group 

 (square-reared, bloom-fed, 2-day-old) and the hardest to kill group of weevils 

 (boll-reared, boll-fed, 9-day-old). The LD-50 values were relatively constant in 

 all tests using Guthion. 



The susceptibility of boll weevils to BHC and toxaphene was influenced to a 

 greater extent by the adult food source than the age of the weevil or its preimag- 

 inal habitat. 



Based on LD-50 values, the order of susceptibility of the boll weevil to BHC 

 and toxaphene was: boll-reared < square-reared, square-fed < bloom-fed, 

 boll-fed < square-fed, and 9-day-old < 2-day-old weevils. 



I960 - Boyd, N. R., Jr., and B. W. Arthur. Biological degradation of 0,0-diethyl 0-naph- 

 thalimido phosphorothioate (Bayer 22408). J. Econ. Ent. 53(5):848-853. 



P 32 -labeled Bayer 22408 (0,0-diethyl O-naphthalimido phosphorothioate) 

 was converted to the oxygen analog, 0-ethyl phosphoric, 0,0-diethyl phosphoric, 

 0,0-diethyl phosphorothioic acids and at least 3 other metabolites by rats, 

 several species of insects (including the boll weevil), and cotton plants. Differ- 

 ences in the degradation of Bayer 22408 by the 3 biological systems were not the 

 result of the number of metabolites but of the amount of each metabolite formed. 

 Bayer 22408 was stable in insects and most of the absorbed material was re- 

 covered as administered; the oxygen analog was formed to a limited extent. Rats 

 degraded Bayer 22408 rapidly to water-soluble phosphoric acids, which were 

 eliminated primarily in the urine. Some Bayer 22408 escaped degradation and 

 was eliminated intact in the feces. Bayer 22408 was not effective as an animal 

 systemic against several ectoparasites feeding on treated rabbits. Bayer 22408 

 was quite stable on the foliage of cotton plants but was not translocated to 

 untreated portions of plants. 



I960 - Brazzel, J. R., and D. A. Lindquist. The effectiveness of chlorinated hydrocarbon 

 insecticide mixtures for control of resistant and susceptible boll weevils. J. 

 Econ. Ent. 53(4):551-554. 



The toxicity of toxaphene and DDT alone and combined in various propor- 

 tions on laboratory-reared toxaphene resistant and susceptible strains of the 

 boll weevil was studied. Toxaphene-DDT mixtures exhibited synergistic effects 

 on resistant weevils, but only additive effects for susceptible ones. A mixture 

 of 4 parts toxaphene and 1 part DDT was the most effective combination tested 

 against resistant weevils. A dosage of 5 to 15 micrograms of toxaphene in 

 combination with DDT was required to produce 50% mortality of resistant 

 weevils, regardless of the amount of DDT in the combination. 



No evidence of synergism was found using mixtures of toxaphene with 

 methoxychlor or DDE. A mixture of Strobane-DDT was slightly less effective 

 than toxaphene- DDT, but the synergistic effect was evident with resistant weevils. 

 Strobane is a mixture of chlorinated terphenes with about 66% of chlorine. 



No evidence was found of seasonal tolerance in field-collected boll weevils 

 to a 2-1 mixture of toxaphene-DDT. 



I960 - Burkhalter, Glenn F., and F. S. Arant. Boll weevil susceptibility to Toxaphene, 

 Endrin, and Guthion in five Alabama localities. J. Econ. Ent. 53(2):31 1-313. 



Laboratory experiments were conducted in 1956 and 1957 to determine the 

 susceptibility of the boll weevil, Anthonomus grandis Boh., to toxaphene, endrin, 

 and Guthion (0,-0-dimethyl S-(4-oxo- 1,2,3, -benzotriazin- 3-(4H)-ylmethyl) 

 phosphorodithioate) in five Alabama localities. The technical insecticides were 

 dissolved in acetone and applied topically to 2-day-old weevils reared from 



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