DISPERSAL OF NORTHERN AND WESTERN CORN ROOTWORMS IN RELATION TO SEX, SIZE, AND REPRODUCTIVE STATUS IN THE SOUTH DAKOTA AREAWIDE MANAGEMENT SITE

Authors: French, Bryan; Chandler, Laurence - Larry; Hammack, Leslie; Beck, David

Submitted to: Entomological Society of America Regional Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 3/2/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Dispersal is a means by which gene flow occurs among populations. We report on dispersal in relation to sex, size and reproductive status of the northern and western corn rootworms (NCR and WCR) in the SD areawide management site. We used emergence cages and sticky traps to capture corn rootworms (CRW) within cornfields. We used sticky traps to capture CRW between soybean and cornfields. Male NCR had larger head capsule sizes than females from all traps. Female WCR tended to be larger than males except for those captured in the borders. For males and females of both species captured between fields, more beetles were captured in the lowest, middle, then highest traps. Sperm was found in the spermatheca in 97% and 96% of NCR and WCR. For NCR and WCR females, 46% and 16% had no eggs, 42% and 75% had unchorionated eggs, and 12% and 9% had chorionated eggs. More female WCR were captured flying from first year corn to soybean than from soybean to first year corn. More male NCR were captured above the corn canopy than were females, and for both female and male NCR, most were captured emigrating from the cornfields. Most female and male WCR were captured immigrating into the cornfields. Sperm was found in the spermatheca in 91% and 92% of NCR and WCR females captured above the corn canopy. For NCR and WCR females, 50% and 24% had no eggs, 35% and 68% had unchorionated eggs, and 15% and 8% had chorionated eggs.