Behavioral Response by Hylobius pales, Pachylobius picivorus (Coleoptera: Curculionidae) and Xylotrechus sagittatus (Coleoptera: Cerambycidae) to Trap Visual and Olfactory Cues and an Estimate of Trap Efficiency

Abstract

A modified Tilles trap and the pyramidal Tedders trap alone or in combination with 2-way pitfall traps were used in north Florida to determine trap capture efficiency and the roles of visual and olfactory cues in the behavior of 2 species of root-feeding weevils, Hylobius pales (Herbst) and Pachylobius picivorus (Germar) (Coleoptera: Curculionidae), and a cerambycid, Xylotrechus sagittatus (Germar) (Coleoptera: Cerambycidae). The 3 species responded strongly to olfactory cues provided by a 5:1 ratio of ethanol and turpentine. Visual cues followed olfactory cues in the host finding and selection hierarchy and were important in the trap response of H. pales and X. sagittatus, but less important for P. picivorus. The Tedders trap captured 18% of the total of the P. picivorus, >70% of the H. pales and >80% of the X. sagittatus. Response to odor and visual cues was more directed toward the point source in H. pales when compared with P. picivorus. More than 80% of P. picivorus landed some distance away from the trap and moved toward it. In contrast, less than 30% of H. pales landed away from or failed to enter the Tedders trap. The numbers of X. sagittatus trapped were greater in traps that were elevated off the ground. Response to the modified Tilles trap confirmed and supported the findings in the other trap configurations. Use of this methodology has potential for monitoring populations of these beetles and determining the behavior and biology of other insect species.