225 



thing else we have found, it is not the only source of boll weevil resistance 

 with which we are working. 



434. ; McCarty J. C, Jr.; Parrott, W. L.; Lindig, 0. H.; and McLaughlin, 

 R. E. 1972. Genetic characteristics of an ebony, pearl strain of boll 

 weevil. J. Econ. Entomol. 65: 1611-1623. 



A strain of Anthonomus grandis Boheman with 2 morphological mutants (ebony 

 body color and pearl eyes) has been mass reared at the USDA Boll Weevil Research 

 Laboratory. Ebony is controlled by a semidominant gene and pearl by a 

 recessive gene. The strain was developed by individual pair matings of 75 

 ebony, pearl, laboratory culture females with 75 wild-type males obtained 

 from southern Mississippi. In the F^ ebony, pearl weevils were recovered. 

 After 5.4 million insects (10.8 million gametes) were reared, a sample of 

 10,600 insects (21,200 gametes) was classified. The gene frequency of pearl 

 was 1.0. The gene frequency of ebony was 0.00033e to 0.9967E. This should 

 result in 1 weevil with wild-type body color in 10 million and all should have 

 pearl eyes. The inability to diapause is under genetic control and was segre- 

 gating in the F generation from the original cross. After 5.4 million insects 

 were reared (approximately 13 generations) the gene frequency was ca. 0.05d to 

 0.95D. Thus, the population had 2 very stable marker genes and was almost 

 homozygous for inability to diapause, a dominant, lethal gene in nature. 



435. ; McLaughlin, R. E.; Parrott, W. L.; and VJouters, C. J. J. 1970. 

 Eliminating Glugea gasti (Protozoa: Microsporidia) from genetic stocks 

 of the boll weevil. J. Econ. Entomol. 63: 1638-1639. 



We eliminated the microsporidian Glugea gasti McLaughlin from genetic 6tocks 

 of the boll weevil, Anthonomus grandis Boheman, capitalizing on the fact that 

 the disease is not transmitted by males, although the gonads are infected. 

 We crossed diseased, mutant males with healthy, wild-type females and recovered 



