SOUTH DAKOTA STUDIES PROVIDE NEW INSIGHT INTO ROOTWORM MANAGEMENT

Authors: Chandler, Laurence - Larry; Patterson, Debra; Riedell, Walter; French, Bryan; FULLER, BILLY - SOUTH DAKOTA STATE UNIV

Submitted to: Internet Web Page
Publication Type: Other
Publication Acceptance Date: 9/30/2003
Publication Date: 9/30/2003
Citation: Chandler, L.D., Hartman, D.A., Riedell, W.E., French, B.W., Fuller, B.W. 2003. South dakota studies provide new insight into rootworm management. Available: www.areawiderootworm.info/final_report.pdf

Interpretive Summary: In 1997, the South Dakota areawide management site was entered into the ARS-sponsored corn rootworm areawide management program, which was used to illustrate the management of corn rootworms over large geographic areas. This site had substantial corn rootworm populations and damage to corn produced annually in the same fields. From 1997 to 2002, 50 to 60 cornfields per year were scouted for corn rootworm populations and damage. Fields were treated with semiochemical baits to manage rootworm populations when threshold levels were met, monitored for effects of baits on beneficial insect populations, used to study corn rootworm beetle movement, and to develop and evaluate new corn rootworm monitoring systems and bait technologies. This site provided new insights into rootworm population ecology and management. In 1997 western and northern corn rootworms were equally distributed across the site, with more westerns noted in continuous cornfields. By 2000 northern corn rootworms were established as the predominant species with substantial numbers emerging from rotated cornfields. Western corn rootworm beetles were managed with semiochemical baits, but northerns were more difficult to manage due to differences in their behavior and subsequently displaced westerns as the primary pest species. New insecticide baits were evaluated that assisted the commercialization process, resulting in two new products on the market. New corn rootworm beetle traps were evaluated resulting in new sample methodology. Insecticide baits were found to be minimally disruptive to beneficial arthropod populations. Areawide management provided a more environmentally sensitive tool for rootworm management.

Technical Abstract: In 1997, the South Dakota areawide management site was entered into the ARS-sponsored corn rootworm areawide management program, which was used to illustrate the management of corn rootworms over large geographic areas. This site had substantial Diabrotica populations and damage to corn produced annually in the same fields. From 1997 to 2002, 50 to 60 cornfields per year were scouted for Diabrotica populations and damage. Fields were treated with semiochemical baits to manage rootworm populations when threshold levels were met, monitored for effects of baits on beneficial insect populations, used to study corn rootworm beetle movement, and to develop and evaluate new corn rootworm monitoring systems and bait technologies. This site provided new insights into Diabrotica population ecology and management. In 1997 D. virgifera virgifera and D. barberi were equally distributed across the site, with more D. v. virgifera noted in continuous cornfields. By 2000 D. barberi were established as the predominant species with substantial numbers emerging from rotated cornfields. D. v. virgifera beetles were managed with semiochemical baits, but D. barberi were more difficult to manage due to differences in their behavior and subsequently displaced D. v. virgifera as the primary pest species. New insecticide baits were evaluated that assisted the commercialization process, resulting in two new products on the market. New corn rootworm beetle traps were evaluated resulting in new sample methodology. Insecticide baits were found to be minimally disruptive to beneficial arthropod populations. Areawide management provided a more environmentally sensitive tool for rootworm management.