Volatile semiochemical impact on trapping and distribution in maize of northern and western corn rootworm beetles (Coleoptera: Chrysomelidae)
1 Field studies evaluated plant attractants and analogues as tools to move corn rootworm beetles (Diabrotica spp.) into areas to be treated with toxic baits for population suppression via mass removal/annihilation of reproductive adults.
2 When dispensed from sticky traps in maize, 2-phenyl-1-ethylamine and 2-phenyl-1-ethanol captured more northern corn rootworm, Diabrotica barberi, than did 4-methoxyphenethanol. Only 2-phenyl-1-ethanol attracted the western corn rootworm, Diabrotica virgifera virgifera, but not until maize matured beyond milk stage.
3 Attraction of D. barberi to the amine, alone or blended with 2-phenyl-1-ethanol, occurred before and after maize flowered but not during intervening silk or blister stages. Attraction recurred during early milk stage at or before 50% emergence of adult female D. barberi or D. v. virgifera, respectively, and before populations declined for the season.
4 Synergistic interaction of 2-phenyl-1-ethylamine with 2-phenyl-1-ethanol in attracting D. barberi females did not occur until maize matured to late milk stage.
5 The amine-alcohol blend (0.44 point sources m−2) doubled the density of D. barberi but not D. v. virgifera when applied to small plots within mostly milk-stage or younger maize. Traps without bait within attractant-treated plots captured more female, but not male, D. barberi than did traps in untreated control plots, hinting that females accounted for most of the observed increase in beetle density.
6 The results suggest that attractants can be used despite phenological limitations to concentrate preovipositional females within field areas and thus to complement a variety of corn rootworm control strategies.
Document Type: Research Article
Affiliations: USDA, ARS, Northern Grain Insects Research Laboratory, 2923 Medary Avenue, Brookings, South Dakota 57006, U.S.A.
Publication date: May 1, 2003