Changes in Oak Gall Wasps Species Diversity (Hymenoptera: Cynipidae) in Relation to the Presence of Oak Powdery Mildew (Erysiphe alphitoides)

• Author(s) / Creator(s)

  • Erbilgin, N.
  • Ghosta, Y.
  • Zargaran, M.R.

• Plant-mediated interactions usually lead to multipartite interactions in a community of organisms. To evaluate the impact of oak powdery mildew Erysiphe alphitoides infestation on the distributions of cynipid oak gall wasps (Hymenoptera: Cynipidae), a field survey was conducted in West Azerbaijan Province, Iran, in 2 consecutive years of 2009-2010. Multiple samples were taken from both infected and uninfected trees (Quercus spp.) at 4 different sites where maximum activity of E. alphitoides occurred and cynipid galls exhibited complete development. The species diversity and richness of gall-forming wasps were estimated and also parameters such as Simpson's index, Shannon's H', and the Sorensen similarity quotient were calculated. Data were also analyzed by independent-samples t-test to compare the mean numbers of galls occurring on infected and uninfected trees. Results clearly indicated that the highest richness and diversity of oak gall-forming wasps were consistently found on uninfected trees at all study sites in the 2 consecutive years. Further, the number and diversity of gall-forming wasps were negatively correlated with the extent (percentage) of pathogen infection, and trees with the heaviest E. alphitoides infection had the lowest numbers of gall-forming wasps. In addition, E. alphitoides decreased the rate of Sorensen's coefficient between regions where oak trees infected with E. alphitoides were sampled. This study demonstrates plant-mediated interactions between a native pathogen and a community of gall-forming insects on oak trees.

• Date created

  2012

• Subjects / Keywords

  • Oak forest
  • Species diversity
  • Cynipid gall wasps
  • Tree-mediated interactions
  • Abundance

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R3S17SS4R

• License

  © 2012 Biodiversity Research Center, Academia Sinica, Taipei. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.