Monday, December 10, 2001 - 2:48 PM

Acoustic signals mediate host finding by Syngaster lepidus, a braconid parasitoid of Eucalyptus longhorned borers, Phoracantha spp

A. L. Joyce, J. G. Millar, and T. D. Paine. University of California, Department of Entomology, Riverside, CA

Syngaster lepidus (Braconidae) was introduced into California as a biological control agent of two Phoracantha spp. (Cerambycidae) which attack Eucalpytus. We investigated whether this parasitoid uses acoustic cues to find and accept its concealed larval hosts. Parasitoid Hymenoptera have been found to exhibit vibrokinesis, but few studies have distinguished between wasps exhibiting vibrokinesis or vibrotaxis to orient toward hosts. The Phoracantha larvae feed under ~1 cm of Eucalyptus bark in the cambium, and larval feeding is audible from a distance. The behavior of female Syngaster lepidus on Eucalyptus log sections containing individual Phoracantha larvae was videorecorded. An ethogram was created to describe the wasp behaviors. Parasitoid orientation toward the host larvae was compared in the presence and absence of larval feeding sounds, and results are reported.

Species 1: Hymenoptera Braconidae Syngaster lepidus
Species 2: Coleoptera Cerambycidae Phoracantha recurva (eucalyptus longhorned borer)
Keywords: vibrotaxis, host finding

The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA