BIONOMIC OF CAMPOLETIS CHLORIDEAE (HYM:ICHNEUMONIDAE)AS A PARASITOID OF THE COTTON BOLLWORM HELICOVERPA ARMIGERA (LEP:NOCTUIDAE) *

The bionomics of Campoletis chlorideae and the regularity of its seasonal fluctuations were studied in Changsha district,Hunan province. Field investigation indicated that there were ten generations of C. chlorideae a year, of which seven occurred in cotton fields. Three peaks of cotton bollworm parasitization by C. chlorideae were observed, early May to late June, mid August to early September, mid September to mid October respectively. One peak occurred in tomato and tobacco fields, the other two in cotton fields. The parasitization rate ranged from 25.1%- 63.1%. The total development time from egg to adult ranged from 13.0 days at 32℃ to 75.5 days at 11.6℃. Each wasp could parasitize the 5-23 second instar larvae of tobacco caterpillar. C. chlorideae could parasitize the cotton bollworm, beet armyworm and tobacco caterpillar, but preferred the cotton bollworm larvae. C. chlorideae could parasitized 1st-3rd instar larvae of the tobacco caterpillar, but seldom parasitzed 4th-6th instar larvae. Moreover, C. chlorideae preferred second instar larvae. Theoretical models for developmental speed, adult longevity and the influence of temperature were proposed. The overwintering of C. chlorideae Uchida was also discussed. Moreover, methods for utilization of C. chlorideae Uchida in crop protection were presented and the bionomics of Campoletis chlorideae in both the Yangtze River Valley and Yellow River Valley were compared.

4代棉铃虫对夏播高粱的为害特点

4代棉铃虫对高粱的为害轻重与高粱播种茬口时间有相关性,对夏播高粱的为害重于麦套高粱。在夏播高粱茬口中,4代棉铃虫为害轻重与品种特性有相关性,对穗型紧凑型品种的为害重于穗型松散型品种。在适合的天气条件下,4代棉铃虫成虫盛期与夏播高粱扬花期相遇是其重发生的主要原因。针对4代棉铃虫在夏播高粱上的为害特点,提出了因地制宜选择合适的抗虫品种、提早播期的农业防治措施。