136 



low level. The 8 applications of malathion in 1965 and 1966 and the 8 appli- 

 cations of azinphosmethyl in 1967 protected the top crop. The program did 

 not achieve eradication, probably because of the difficulty of thorough 

 treatment of small farms and the high reproductive potential of the surviving 

 weevils. The level of suppression achieved indicates that the method could 

 be used to reduce populations low enough to permit delivery of a high ratio 

 of stetile to surviving native weevils the following season. 



255. , and Leggett, J. E. 1969. Winter survival in Arizona of thurberia 

 weevils released from thurberia bolls. J. Econ. Entomol. 62: 467-470. 



Anthonomus grandis thurberiae Pip-^ce, released from hibernation cells in 

 bolls of wild cotton, Gossypium t'.iurberi Todaro, in December and February 

 survived until late June and July. Longevity of released weevils increased 

 when moisture was made available. However, a large percentage of weevils 

 remaining in hibernation cells were still alove when all released weevils 

 had died. In laboratory tests, released weevils readily moved to moist 

 niches. 



256. ; Leggett, J. E.; and Bonham, C. D. 1970. Winter survival of the 

 boll weevil complex in Arizona. J. Econ. Entomol. 63: 1071-1074. 



In Arizona, adult Anthonomus grandis Boheman from cultivated cotton emerged 

 from buried and unburied bolls throughout the winter whenever the temperature 

 exceeded the physiological threshold. Emergence was prevented by burying 

 the bolls to a depth of 30 cm. A few weevils were found during the winter 

 in desert trash adjacent to fields that had had large infestations the 

 previous growing season. Most overwintering weevils in Arizona did not meet 

 the criteria of full diapause associated with the southeastern boll weevil. 



