|Lopez, Juan De Dios|
Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2006
Publication Date: 6/16/2006
Citation: Blanco, C.A., Sumerford, D.V., Lopez, J., Hernandez, G. 2006. Mass mating behavior of heliothis virescens (lepidoptera: noctuidae) males captured in pheromone traps mated with laboratory-reared females: measures of reproduction, egg production and adult mortality. Journal of Cotton Science. Volume 10 page 105-113
Interpretive Summary: Since 1996, the Southern Insect Management Research Unit of USDA-ARS in Stoneville, Mississippi has received thousands of field-captured bollworm (corn earworm) male moths to test their susceptibility to Bacillus thuringiensis (Bt) protein(s) expressed by transgenic (Bt) cotton. This task serves to monitor potential Bt resistance in the field as well as generate data for industry to fulfill their annual registration requirements. Of those tested moths, information on the proportion of males that actually mated with the laboratory females and produce offspring can not be easily obtained. These data (copulation frequency, offspring, mortality of moths, etc.) are of the outmost importance to calculate the effective genetic diversity of the tested samples. From the information generated in this study, our data indicate that it takes two days for field-captured males to produce their most genetically diverse offspring, an important finding to improve our current methodology of monitoring bollworm for resistance to Bt cotton.
Technical Abstract: Testing the offspring of field-captured bollworm (Helicoverpa zea) moths offers reliable indicators of their natural behavior and susceptibility to insecticides. In this study laboratory-reared females mass mated for one to five days with pheromone trap-captured (wild) or laboratory-reared males were studied in order to assess the highest genetic diversity potential and peak female offspring. Females mated with wild males obtained their highest number of copulations, produced the largest proportion of fertile eggs and lived longer when mass mated for 2 days. Field captured moths copulated at a lower frequency than laboratory-reared males. Feral females mated with laboratory males had significantly higher spermatophores (1.71+ 0.06) than feral females mated with feral males (0.43 + 0.06). Higher mortality was observed in laboratory-reared males and females in the presence of the opposite sex than under same-sex mass mating conditions at the same crowding ratio, indicating that copulations carry important consequences in longevity. From the information obtained, offspring of wild males and laboratory females mass mated for two days obtained the optimal sampling of the genetic diversity of population for monitoring Helicoverpa zea for resistance to Bt proteins.