Corn rootworms in North Dakota: A state-wide survey and a comparison of two sticky traps for monitoring adult activity

Monday, November 17, 2014
Exhibit Hall C (Oregon Convention Center)
Veronica Calles Torrez , Entomology, North Dakota State University, Fargo, ND
Janet Knodel , Plant Pathology, North Dakota State University, Fargo, ND
Mark A. Boetel , Entomology, North Dakota State University, Fargo, ND
Patrick Beauzay , Plant Pathology, North Dakota State University, Fargo, ND
Corn rootworms (Coleoptera: Chrysomelidae: Diabrotica spp.) are major pests of corn, Zea mays L. (Poaceae), in North America. Corn is an important crop for ethanol fuel production and livestock feed in North Dakota, with about 3.5 million acres being harvested in 2013. Since the 1990s, this pest has been become increasingly difficult to control through adaptations to various pest management strategies. The objectives of this study were to determine the geographic distribution, density, and species composition of Diabrotica species in North Dakota and to compare the effectiveness of yellow Pherocon AM/NB and green ScentryTM Multigard sticky traps for monitoring these pests. From August to October of 2013, 29 fields in 18 North Dakota counties were monitored for corn rootworm beetle activity by using the two sticky trap types. Western corn rootworms, Diabrotica virgifera virgifera LeConte, and northern corn rootworms, D. barberi Smith & Lawrence, were most common in the southeast region of the state. Densities of both species in that part of the state were at about 10 beetles per trap per week. Northern corn rootworms were more abundant in northern region of the state, but at low densities. Overall, the yellow Pherocon AM/NB traps were found to be better for monitoring corn rootworm adults in this experiment, as they captured significantly more beetles than the green ScentryTM Multigard sticky traps (t-test, P<0.026). Further survey work is needed to more accurately define Diabrotica species distributions in North Dakota.