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ARS Home » Midwest Area » Columbia, Missouri » Plant Genetics Research » Research » Publications at this Location » Publication #348842

Research Project: Genetics and Genomics of Complex Traits in Grain Crops

Location: Plant Genetics Research

Title: Sugar preferences of western corn rootworm larvae in a feeding stimulant blend

Author
item Bernklau, Elisa - Colorado State University
item Hibbard, Bruce
item Bjostad, Louis - Colorado State University

Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2018
Publication Date: 7/1/2018
Citation: Bernklau, E.J., Hibbard, B.E., Bjostad, L.B. 2018. Sugar preferences of western corn rootworm larvae in a feeding stimulant blend. Journal of Applied Entomology. 142(10):947-958. https://doi.org/10.1111/jen.12540.
DOI: https://doi.org/10.1111/jen.12540

Interpretive Summary: The western corn rootworm is a major pest which has developed resistance to a number of management tactics. New tactics are needed to replace those being lost to resistance. Feeding behavior of the larvae is a potential area of vulnerability. Feeding behavior, and feeding intensity of western corn rootworm larvae were evaluated in response to synthetic feeding stimulant blends to determine larval preferences among the three maize-root sugars (glucose, fructose and sucrose) in the active blend and to determine if any single sugar can substitute for the 3-sugar combination in a feeding stimulant blend to simplify potential applications. These experiments demonstrated the strong affinity that western corn rootworm larvae have a for the natural sugars found in maize roots, and also showed that sucrose is the most preferred of the maize root sugars. This data will be applicable to future studies utilizing feeding stimulants to enhance the effectiveness of insecticides.

Technical Abstract: Feeding behavior, feeding intensity and staying behavior of neonate western corn rootworm larvae (Diabrotica virgifera virgifera LeConte) were evaluated in response to synthetic feeding stimulant blends to determine larval preferences among the three maize-root sugars (glucose, fructose and sucrose) in the active blend and to determine if any single sugar can substitute for the 3-sugar combination in a feeding stimulant blend. These experiments demonstrated the strong affinity that western corn rootworm larvae have a for the natural sugars found in maize roots, and also showed that sucrose is the most preferred of the maize root sugars. Only the blend containing sucrose at 30 mg/ml elicited feeding that was not significantly different than the natural glucose:fructose:sucrose blend. In subtraction bioassays, removal of sucrose from the blend resulted in significantly fewer larvae feeding. When the three-sugar blend was substituted with one of a number of various monosaccharides, significantly fewer larvae fed on all of the blends compared to the control blend with sucrose. In tests with blends containing individual di-or trisaccharides, only the blend with maltose was not significantly different than the control blend with sucrose. In feeding choice tests, larvae preferred a blend containing sucrose over blends with either glucose or fructose, but larvae chose equally between a blend with sucrose and a blend containing the three sugar-mixture found in maize roots. Based on these results, a feeding stimulant blend with glucose (30 mg/ml), fructose (4 mg/ml) and sucrose (4 mg/ml) elicits the strongest feeding response, but sucrose alone, in amounts equivalent to the total maize root-sugar concentration (30-38 mg per ml), could serve as a substitute for the 3-sugar mixture in a synthetic feeding stimulant blend.