Experiments designed to evaluate the potential of non-pheromonal attractants for concentrating corn rootworm beetles within field plots were done in commercial maize in Brookings Co., SD over 3 years. Plots measuring 9.1 x 9.1 m were treated with 36 evenly spaced, attractant dispensers. Each released 2-phenyl-1-ethylamine and 2-phenyl-1-ethanol at estimated rates of 1.5 and 0.8 mg/day, respectively. This binary blend primarily affects northern corn rootworm, Diabrotica barberi Smith & Lawrence, but data were also collected for western corn rootworm, Diabrotica virgifera virgifera LeConte. Most attempts to concentrate beetles in maize plots were done during late vegetative and milk stages. These were the earliest stages when beetle olfactory responses to sticky traps baited with the binary blend were demonstrable, although synergy between blend components in attracting northern corn rootworm females was not evident until maize developed beyond early milk stage. Beetle counts made 2, 24 and 48 h after treatment on maize plants located about midway between attractant sources indicated that treated plots contained almost twice as many northern corn rootworm beetles, at a minimum, as did matched control plots. Captures on sticky traps without lure that were placed in attractant-treated plots suggested that the increase was attributable to more female beetles. Unlike sticky traps, medicine-vial traps without lure produced low captures not varying between treatments. No significant effects on western corn rootworm densities or trap captures occurred. Only about 50% of northern corn rootworm females emerged from the soil by milk stage, when female responsiveness to the binary blend recurred following its loss during maize silking. These results suggest attractants could reduce field areas requiring treatment with the cucurbitacin-based toxic baits that are under evaluation as tools to curtail corn rootworm oviposition via annihilation of females.
Species 1: Coleoptera Chrysomelidae Diabrotica barberi (northern corn rootworm)
Species 2: Coleoptera Chrysomelidae Diabrotica virgifera virgifera (western corn rootworm)
Species 3: Zea mays (maize)
Keywords: attractants, corn rootworm beetles
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA