291 



(2, 6-dif luoro-N-[ [ [4-(trifluoromethyl)phenyl]amino]carbaryl]benzaniide) in ace- 

 tone. Wlien the treatments were combined for 100,000 adults of mixed sexes, the 

 sterility level was 99±% when fumigation time was 90 min or more and the age of 

 the weevils at the time of treatment made little difference in the resulting 

 sterility level. Bisazir is a male sterilant, and penfluron inhibits the re- 

 productive potential of females, and both must be used to obtain sterility when 

 mixed sexes are treated. ■' 



556. McGarr, R. L., and Chapman, A. J. 1966. Initial field tests with methyl 

 parathion and EPN in Mexico against the boll weevil. J. Econ. Entomol. 

 59: 1529. 



Methyl parathion is now probably the insecticide most widely used for cotton in- 

 sects in the Western hemisphere. EPN (0-ethyl 0-p-nitrophenyl phenylphosphono- 

 thioate) though effective against several cotton insects has not been used ex- 

 tensively. This report describes the 1st field tests with these insecticides 

 against the boll weevil, Anthonomus grandis Boheman, near Manuel, Tamaulipas, 

 Mexico, in the winter of 1951-52. The early information on the performance of 

 the compounds was used when experiments were planned at laboratories in the United 

 States for the 1952 growing season. The record has historical value and the data 



should be made available to permit later determination of any resistance that 



*■ 

 boll weevils in this area may have developed to these insecticides. 



557. , and Wolfenbarger, D. A. 1968. Aerial applications of ultra-low-volume 

 methyl parathion for control of cotton insects. J. Econ. Entomol. 61: 

 1107-1108. 



In four field tests in .he lower Rio Grande Valley of Texas methyl parathion 

 applied at 1.0 to 1.5 lb per acre in an ultra-low-volume spray gave good con- 

 trol of the bollworm, Heliothis .zea. the tobacco budworm, H. virescens and the 

 boll weevil, Anthonomus grandis . The average yield in seed cotton/acre was 2544 

 lbs in the treated plots compared with 1066 lbs in the untreated plots. 



