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2nd generation larvae that are subject to summer diapause. The 

 intensity of this diapause varies depending on the prevailing 

 temperatures and is apparently terminated by lower fal 1 temperatures. 

 If diapause is broken in late September, the larvae will complete 

 their development and pupate, producing 2nd generation adults by mid- 

 October or later. These adults will then deposit fast-developing 

 eggs, diapause eggs, or a combination of both. If they are diapause 

 eggs, they will eventually produce the 1st generation of adults for 

 the succeeding year. If they are nondiapause eggs, the resulting 

 larvae will be subject to cool fall and winter temperatures and may 

 enter diapause, producing lst-generation adults for the next season. 



In a three-generation (tri vol tine) strategy, the lst-generation 

 adults emerge in late March or early April, early enough to produce a 

 complete, nondiapausing 2nd generation before the summer's heat. 

 Second generation adults then deposit fast-developing eggs that hatch 

 in eight to ten days, producing 3rd-generation larvae that are subject 

 to summer diapause. These do not pupate until fall, and the resulting 

 adults deposit nondiapause eggs, diapause eggs or a mixture of both, 

 as in a bi vol tine program. In either case, the eggs or larvae are 

 subject to winter diapause. 



A 4th generation is possible if 3rd-generation larvae develop 

 normally and pupate in late summer, producing adults by early 

 September. These adults will most likely lay 100% nondiapause eggs 

 and the resulting 4th generation larvae will be able to complete their 

 development before diapause-inducing fall and winter temperatures set 

 in. Any progeny from this 4th generation will be subject to diapause. 



