Influence of the community of associates on Sirex noctilio brood production is contextual. (1st November 2019)

• Record Type: Journal Article
• Authors: Haavik, Laurel J.; Slippers, Bernard; Hurley, Brett P.; Dodds, Kevin J.; Scarr, Taylor; Turgeon, Jean J.; Allison, Jeremy D.
• Is Part Of: Ecological entomology. Volume 45:Number 3(2020)
• Page Start: 456
• Page End: 465
• Publication Date: 2019-11-01
• Subjects: Biotic resistance -- enemy release -- invasive species -- natural enemy exclusion -- wood borer; Insects -- Ecology -- Periodicals; Entomology -- Periodicals; 595.7
• DOI: 10.1111/een.12810
• Languages: English
• ISSNs: 0307-6946

Abstract

Abstract : 1. Competition and predation are important components of biotic resistance, which helps define the invasibility of an ecosystem. 2. To search for evidence of biotic resistance to the European woodwasp, Sirex noctilio Fabricius, in North America, cages were used to experimentally exclude the community of associates (natural enemies and competitors) from infested logs. Specifically, the study assessed S. noctilio brood production in pine forests in Ontario and New York, where there was a rich existing community of associates (other wood borers, bark beetles and associated fungi, and parasitoids), and in South Africa, where siricid wasps and pines are not native and a similar associate community is not present. In addition, in Ontario, associates were excluded by size, and for different periods of time to identify important associates and their temporal dynamics. 3. Evidence was found that biotic factors limit S. noctilio in North America, whereby exclusion of natural enemies and competitors had a positive influence on the abundance or presence of S. noctilio brood in Ontario and New York. This influence was absent in South Africa. 4. It is unclear which member(s) of the associated insect community in North America were most important in limiting S. noctilio brood production, although they probably acted quickly (< 2 weeks) following S. noctilio oviposition. 5. Further study is needed to determine whether associates have limited S. noctilio populations in pine forests throughout northeastern North America, and which specific natural enemies and/or competitors are important. Abstract : A manipulative field experiment was established in three different countries to evaluate whether natural enemies and/or predators (associates) limited S. noctilio brood production. Biotic factors limited S. noctilio brood in North America, where an associate community exists, but not South Africa, where the associate community is largely absent. Associates that limited S. noctilio in North America were not identified, though they were present shortly after S. noctilio oviposition.