Semiochemicals From Fungal Associates of Bark Beetles May Mediate Host Location Behavior of Parasitoids

  • Author(s): Sullivan, Brian T.; Berisford, C. Wayne
  • Date: 2004
  • Source: Journal of Chemical Ecology, Vol. 30, No. 4, April 2004
  • Station ID: --

Abstract

In laboratory olfactometer bioassays, females of two hymenopteran parasitoid species, Roptrocerus xylophagorum (Ratzeburg) (Hymenoptera: Pteromalidae) and Spathius pallidus (Ashmead) (Hymenoptera: Braconidae), were attracted to odors from bark or bolts of loblolly pine, Pinus taeda L., colonized by bluestain fungi (genus Ophiostoma) associated with the parasitoids' bark beetle hosts. Mock-inoculated bolts and bark were less attractive or unattractive in these bioassays. Bark infested with host larvae that lacked their fungal and other normal microbial associates was attractive to R. xylophugorum females, but was less so than bark infested with larvae possessing their normal complement of associated microbes. In contrast, in oviposition bioassays, R. xylophagorum females spent approximately equal time searching, made similar numbers of oviposition attempts, parasitized similar percentages of hosts, and laid similar numbers of eggs in bark fragments infested with either associate-free or associate-bearing host larvae. Furthermore, in field bioassays using bluestain-inoculated or mock-inoculated loblolly pine bolts as sources of attractants, the numbers of parasitoids attracted by the two treatments did not differ significantly and the two treatments were less attractive than bolts naturally infested with bark beetle larvae. Whereas our laboratory olfactometer data suggest that bark beetle fungal associates may enhance attraction of some parasitoids, our bioassays with associate-free hosts indicate that associate-produced are not required for short-range host location and parasitization. In addition, our field trials indicated that long-range attraction of parasitoids to the host-fungi-tree complex is not caused simply by an interaction between bluestain fungi and tree tissues.

  • Citation: . . Semiochemicals From Fungal Associates of Bark Beetles May Mediate Host Location Behavior of Parasitoids. Journal of Chemical Ecology, Vol. 30, No. 4, April 2004.

Pristine Version Available

An uncaptured, or “pristine” version of this publication is available. It has not been subjected to OCR and therefore does not have any errors in the text. However, it is a larger file size and some people may experience long download times.

Download “Pristine” Publication
(PDF; 1.2 MB)


Requesting Publications

You can order print copies of our publications through our publication ordering system. Make a note of the publication you wish to request, and visit our Publication Order Site.

Publication Notes

  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
  • Our on-line publications are scanned and captured using Adobe Acrobat. During the capture process some typographical errors may occur. Please contact the SRS webmaster if you notice any errors which make this publication unuseable.
  • To view this article, download the latest version of Adobe Acrobat Reader.