313 



608. ; Cleveland, T. C; Daum, R. J.; and Bell, M. R. 1969. Development 

 of the bait principle for boll wee\ 11 control. IV. Field tests with a 

 bait concaiaing a feeding stimulant and the sporozoans Glugca gasti 

 and Mattesia grandis . J. Invertebr. Pathol. 13: 429-441. 

 Bait containing feeding stimulant and one of two protozoan pathogens (Ma ttesia 

 grandis or Glugea gasti ) was tested against field populations of boll weevils 

 (Anthonomus grandis ) in the fall of 1966 throughout the season in 1967. In 

 1966, the weevils that subsequently diapaused responded well to the bait since 

 60-80% had ingested the red marker dye. Also, although the quantity of the 

 pathogen was limited, both diseases were found in the populations. In 1967, 

 50-70% of the weevil population present in late June and early July (overwinter- 

 ed weevils) ingested bait containing G. gasti , and as many as 80% were diseased. 

 In contrast, the F, and ensuing reproducing generations present from mid- July 

 through August did not respond well: only 2-19% were marked, and only 11-25% 

 were diseased. Then after August 31, as the weevils began to enter diapause, 

 the population again responded well, and 50-70% were marked and diseased. 

 Also, over 60% of the weevils subsequently collected from woods trash from 

 winter hibernation sites were marked and diseased. The treatment with the 

 pathogens in 1967 caused 96% winter mortality of boll weevils compared with 

 84% in nearby untreated areas. In addition, large populations of insect preda- 

 tors were found in the treated area, and several gallons of one species were 

 collected in samples of woods trash examined in April 1968. 



609. ; Daum, R. J.; and Bell, M. R. 1968. Development of the bait principle 

 for boil-weevil control. III. Field-cage tests with a feeding stimulant 

 and the protozoan Mattesia grandis (Neogregarinida) and a microsporidian. 

 J. Invertebr. Pathol. 12: 168-174. 

 When Mattesia grandis or a microsporidian were incorporated into a bait contain- 

 ing a feeding stimulant and a marker dye, and tested for suppression of a caged 



