toxaphene and a high tolerance to dieldrin. In field experiments much better 

 control was obtained with Sevin (1-naphthyl N-methyl carbamate) and such 

 organic-phosphorus compound as Guthion (0,0- dimethyl S- (4-oxo-3H- 1,2,3,- 

 benzotriazine-3-methyl) phosphorodithioate) and malathion than with toxaphene 

 and dieldrin. Dosages of toxaphene, dieldrin, and heptachlor 2 and 3 times those 

 effective in previous years, failed to control the cotton fleahopper. Sevin, Guthion, 

 malathion, toxaphene plus DDT, dieldrin plus DDT, and DDT alone were effective, 

 but DDT has not been used against the cotton fleahopper for 10 years in this area. 



1961 - Brazzel, J. R. Boll weevil resistance to insecticides in Texas in 1960. Tex. Agr. 

 Expt. Sta. Prog. Rpt. 2171. Mar. 4. 



A survey was conducted during I960 to determine the status of insecticide 

 resistance in the boll weevil in Texas. Boll weevils were collected from 20 areas 

 of the State and treated with endrin and toxaphene. Results indicated 4 general 

 areas with resistance levels sufficient to prevent economic control with these 

 insecticides; these areas include parts of Hidalgo, Brazos, Maverick, Robertson, 

 Burleson, and Bowie Counties. The central and north-central Texas areas ap- 

 peared to be intermediate insofar as resistance was concerned. Weevils obtained 

 from the remainder of the State were susceptible. There was evidence of a 

 considerable reversion to susceptibility in the Mumford area, the first in which 

 resistance was observed in 1956. 



Since the results of this investigation are based on limited data, the classi- 

 fications of areas as resistant or susceptible, in this report, should be considered 

 only as an indication of the situation in any particular area. 



NUTRITION 



1958 - Leigh, T. F., and Theo Watson. Food and the fat content of the cotton boll weevil. 

 Ark. Farm Res. p. 6. May-June. 



The relationship between food eaten and fat content was studied. Newly 

 emerged weevils from bolls contained 3.55% fat based on live weight, those newly 

 emerged from squares - 1.34%, emerged from squares and fed on terminal 

 growth 8 days - 2.21%, fed squares 8 days - 7.7%, and fed on bolls 8 days - 12.16% 

 fat. 



1958 - Vanderzant, Erma S., and T. B. Davich. Laboratory rearing of the boll weevil. 



A satisfactory larval diet and oviposition studies. J. Econ. Ent. 5 1(3):288-291 . 



Five generations of the boll weevil were reared aseptically from egg to 

 adult on a semi-synthetic diet containing soybean protein, sucrose, corn oil, 

 cholesterol, choline, vitamins, yeast extract, salts, cellulose alginate, agar, and 

 water. The adults were allowed to feed and oviposit on squares. Average egg 

 production was 3 eggs per female per day, with a maximum of 7 eggs. Cotton 

 cotyledons also were found to promote oviposition of newly emerged adults. 

 Weevils fed but did not oviposit on artificial diet unless cotton plant extracts 

 were added. Oviposition also occurred on squares ■without bracts and squares 

 that had been found, remolded, and coated with paraffin. 



1959 - Brazzel, J. R., T. B. Davich, and Klaus Raven. Rearing boll weevils on an artifi- 



cial diet. Tex. Agr. Expt. Sta. Misc. Pub. 353. Apr. 30. 



A technique was developed for rearing large numbers of boll weevils from 

 egg to adult in lots of 50 on an artificial diet under close confinement. The addi- 

 tion of a mixture of sorbic acid and methyl parahydroxybenzoate (methyl paraben) 

 to the diet eliminated the necessity of aseptic procedures. About 70% of the eggs 

 transferred to the diet developed into adults in 14 to 18 days. Weevils reared on 

 this media were uniform in size and averaged about 12 milligrams in weight. 



1959 - Earle, N. W., R. C. Gaines, and J. S. Roussel. A larval diet for the boll weevil 

 containing an acetone powder of cotton squares. J. Econ. Ent. 52(4):710-712. 



A larval diet for the boll weevil was developed using a protein source natural 

 to the species--an acetone powder from squares, bolls, or leaves from the cotton 



155 



