Response of Torymus sinensis, a parasitoid of the gallforming Dryocosmus kuriphilus, to olfactory and visual cues

Ignazio Graziosi, Lynne K. Rieske

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


Torymus sinensis (Hymenoptera: Torymidae) has been manipulated extensively in biological control programs targeting the globally invasive Asian chestnut gall wasp, Dryocosmus kuriphilus (Hymenoptera: Cynipidae). The life cycle of T. sinensis is synchronized with gall wasp larval development to allow effective gall wasp population suppression and a reduction in gall formation. In spite of its extensive use for biological control, relatively little is known about its host location and host acceptance behavior. We investigated T. sinensis host location behavior using a Y-tube olfactometer. Adult females were tested for their response to olfactory and visual cues associated with D. kuriphilus galls and chestnut foliage. Adult parasitoids were not attracted by the odor of fresh galls alone, and had a negative response to the visual cues of galls and chestnut foliage when odor cues were not provided. However, the combination of olfactory and visual stimuli provided by a fresh gall coupled with chestnut foliage elicited a strongly positive response. This positive response persisted even when the fresh gall was replaced by an inert surrogate gall, provided the visual stimulus remained and the olfactory cues from fresh galls were available. Our results indicate that both visual and olfactory cues are required to enable T. sinensis to successfully find suitable hosts. These findings improve our understanding of the stimuli that influence T. sinensis host location behaviors leading to successful gall wasp parasitization, and may enhance our ability to manipulate T. sinensis for gall wasp management.

Original languageEnglish
Pages (from-to)137-142
Number of pages6
JournalBiological Control
Issue number2
StatePublished - Nov 2013

Bibliographical note

Funding Information:
The authors thank Kenneth Haynes, Gary Micsky and Lori Nelson for assistance and advice. Kenneth Haynes and John Obrycki kindly reviewed an earlier version of this manuscript. This work was funded in part by the Italian Fulbright Commission (to IG) and McIntire Stennis Funds from the Kentucky Agricultural Experiment Station . The information reported in this paper (No. 13-08-04 ) is part of a project of the Kentucky Agricultural Experiment Station and is published with the approval of the Director.


  • Asian chestnut gall wasp
  • Biological control
  • Host location
  • Olfactometer

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Insect Science


Dive into the research topics of 'Response of Torymus sinensis, a parasitoid of the gallforming Dryocosmus kuriphilus, to olfactory and visual cues'. Together they form a unique fingerprint.

Cite this