Oviposition behaviour and response of Monochamus scutellatus (Coleoptera: Cerambycidae) to conspecific eggs and larvae

Abstract

Abstract The oviposition behaviour of white‐spotted sawyer beetle Monochamus scutellatus (Say) (Coleoptera: Cerambycidae) females was studied under laboratory and field conditions. Females walked over the bark surface and stopped to palpate it with their labial and maxillary palpi. Once a potential oviposition site was located, the female excavated a scar in the bark with her mandibles, deposited an egg and brown plug in the scar and inserted her mandibles again into the scar prior to leaving the area. Female M. scutellatus preferred to lay eggs on bolts containing no eggs (control) to those containing eggs from other females, but did not show this preference when provided with control bolts and those containing their own eggs. When females were provided with bolts containing their own eggs and bolts containing eggs from other females, they laid more eggs on bolts containing their own eggs. Females laid more eggs on control bolts than on bolts containing their own larvae or larvae from other females. The brown plug in the oviposition scar may provide a protective barrier to the egg, a chemical message that the site is occupied, or both.