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United States Department of Agriculture

Agricultural Research Service

Title: Size-Based Reproductive Behavior of Northern Corn Rootworms

Authors
item French, Bryan
item Hammack, Leslie
item Flaskey, Jason
item Beck, David

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 9, 2004
Publication Date: March 30, 2004
Citation: French, B.W., Hammack, L., Flaskey, J.S., Beck, D.A. 2004. Size-based reproductive behavior of northern corn rootworms. Abstract published to the world wide web by the North Central Branch of the Entomological Society of America and presented at the 2004 annual meeting, March 28-31, 2004, Kansas City, MO.

Technical Abstract: Male insects often compete for access to female ova. Where males compete directly for females, larger males frequently have mating advantages over smaller males. Additionally, many female insects often discriminate against potential mates based on body size. This discrimination can occur prior to mating (pre-copulatory), during mating (copulatory), and following mating (post-copulatory). Northern corn rootworms (NCR) are sexually dimorphic with respect to head capsule width, which correlates with pupal and adult body weight. Here, we report on NCR reproductive behavior in relation to male and female size. We used pupal weight (mg) as initial size indicators. We paired several combinations of large and small males with large and small females in 60 x 15 mm petri dishes. For each sex, large and small individuals were > and < 1 SD about the mean, respectively. We also paired average sized males and females for comparisons, which were within 1 SD of the mean for each sex. All individuals were sexually mature virgins obtained as pupae. We videotaped all unsuccessful mating pairs for at least two hours and successful mating pairs until copulation was completed. Females were housed individually with ample food, water, and oviposition dishes and placed in growth chambers. Oviposition dishes were changed weekly until the females died. Data are analyzed with respect to successful matings and fecundity. Not only is our data germane to evolutionary theory, it also may have important implications with respect to the evoluation of resistance to transgenic corn targeting rootworms.

Last Modified: 7/22/2014