weevil and the bollworm (Heliothis zea (Boddie)) in field-plot experiments con- 

 ducted in 1958. Sprays containing calcium arsenate at 7 lbs., Monsanto CP-7769 

 (hexaethyl (ethylthiomethylidine) triphosphonate) at 0.5 pound, or dicapthon at 

 1.0 lb. per acre were as effective in boll weevil control as dieldrin at 0.38 lb. 

 or Guthion (0,0-dimethyl S-(4-oxo- 3H- 1 ,2,3-benzotriazine- 3-methyl) phos- 

 phorodithioate) at 0.25 lb. per acre. 



1959 - Enkerlin S., Dieter. Different concentrations of Thiodan for the control of cotton 

 insects. J. Econ. Ent. 52(6):1 068- 1 069. 



Three small-plot experiments were conducted in Mexico to evaluate the ef- 

 fectiveness of Thiodan (6,7,8,9, 10, 10-hexachloro, 1 ,5,5a,6,9,9a-hexahydro- 6,9- 

 methano-2,4,3-benzodioxathiepin- 3-oxide) in the control of cotton fleahopper 

 ( Psallus seriatus (Reut.)), bollworm ( Heliothis zea (Boddie)), cabbage looper 

 ( Trichloplusia ni (Hbn.)), and boll weevil (Anthonomus grandis Boh.). Dust 

 formulations were used for the first and third experiments, and sprays for the 

 second. Thiodan 3% and 4% dust as well as sprays containing 0.52 and 0.32 

 kilograms of technical thiodan per hectare gave good results compared with 

 other commonly used insecticides. 



1959 - Mistric, W. J., Jr., and E. J. Spyhalski. Response of cotton and cotton pests to 

 thimet seed-treatment. J. Econ. Ent. 52(5):807- 81 1 . 



Coker 100W cottonseed treated with Thimet (0,0-diethyl S-(ethylthio) 

 methyl phosphorodithioate) was evaluated in replicated field tests at 4 widely 

 separated locations in North Carolina during 1955-56. Thimet exhibited pro- 

 nounced effects both upon the cotton plant and upon the pests which attack cotton. 

 Thimet seed-treatments were particularly effective in controlling thrips, 

 Frankliniella fusca (Hinds), F. exigua (Hood), F. tritici (Fitch), Thrips tabaci 

 (Eind„), and the cotton aphid, Aphis gossypii (Glov.), until the time of squaring. 

 This material afforded seasonal protection from spider mites, Tetranychus 

 cinnabarinus (Bois.) and T. telarius (L.). Thimet was partially effective in re- 

 ducing boll weevil infestations throughout the season, but the use of this mate- 

 rial favored the development of bollworm, Heliothis zea (Boddie), and tobacco 

 budworm, H. virescens (F.), infestations. Delayed fruiting of cotton appeared to 

 be the most detrimental characteristic associated with the use of Thimet. 

 However, certain adverse effects upon the germination, emergence, and vegeta- 

 tive growth of cotton were also noted. 



1959 - Parencia, C. R., Jr. Comparative yields of cotton in treated and untreated plots 

 in insect-control experiments in central Texas, 1939-1958. J. Econ. Ent. 

 52(4):757-758. 



Field experiments for the control of cotton insects have been conducted each 

 year since 1939, when the U. S. D. A. Cotton Insects Laboratory was established 

 at Waco. The primary objective has been to evaluate insecticides and methods of 

 application against the various pests. Yields from fields or plots treated with 

 candidate insecticides have been compared with those receiving a standard in- 

 secticide and with those receiving no treatment. The insects of primary im- 

 portance in most years were the boll weevil ( Anthonomus grandis Boh.) and the 

 bollworm ( Heliothis zea (Boddie)). The average increase in yield from treated 

 over untreated plots was 309 pounds of seed cotton per acre, or 41.8%. 



1959 - Walker, J. K., Jr., and R. L. Hanna. Field plot insecticide tests for the control 



of the boll weevil and the bollworm in 1958. Tex. Agr. Expt. Sta. Prog. Rpt. 2069. 

 Jan. 26. 



Five field plot tests designed to give information on the effectiveness of 

 several insecticides were conducted in the Brazos River Valley. Chlorinated 

 hydrocarbon materials as a group appeared to be less effective for the control of 

 the boll weevil than most other insecticides tested. Sevin gave excellent boll 

 weevil control. Other materials showing promise were dicapthon and Trithion. 



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