Title: Female fecundity and longevity in Northern Corn Rootworm (Coleoptera: Chrysomelidae) in relation to multiple mating and body size Authors
|Hammack, Leslie -|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 14, 2011
Publication Date: March 15, 2011
Citation: French, B.W., Hammack, L. 2011. Female fecundity and longevity in Northern Corn Rootworm (Coleoptera: Chrysomelidae) in relation to multiple mating and body size. Entomological Society of America North Central Branch annual meeting, Minneapolis MN, March 13-16, 2011. Technical Abstract: A single mating generally supplies female insects with enough sperm to fertilize a lifetime of eggs; however, many females mate repeatedly during their lifetime. It is believed that female northern corn rootworm mate only once in their lifetime. We paired combinations of large, small, and average sized male and female northern corn rootworm in Petri dishes. Copulating females were caged individually with ample food, water, and an oviposition dish and placed in growth chambers. Each week until death, females were provided with oviposition dishes and the opportunity to mate with an average sized male. Of 201 copulating females, 63 mated twice and five mated three times, but neither the proportion of females that copulated more than once nor their age at first copulation varied with cross type. Females tended to re-mate at a younger age when originally mated to small males. We found no differences in longevity or in total and viable egg numbers with cross type. Females that mated more than once lived longer than singly mated females. These females also laid more eggs and viable eggs. Should greater longevity of multiply mated females and thus their greater fecundity occur under field conditions, then reproductive success of these females should exceed that of singly mated females. Female corn rootworms resistant to Bt corn could enhance offspring survival by maximizing fertilization of their eggs by Bt resistant males. Further research on the reproductive biology of corn rootworms is needed to fully understand the evolution of Bt resistance.