Date of Award

Spring 3-30-2020

Semester of Degree


Document Type

Restricted Access Dissertation

Degree Name

Ph.D. in Environmental and Forest Biology


Environmental and Forest Biology

Major Professor

Stephen Teale

Steering Committee Member

Peter Silk

Steering Committee Member

Ann Hajak


The Eurasian woodwasp, Sirex noctilio Fabricius (Hymenoptera: Siricidae), is a destructive forest pest in pine plantations of the Southern Hemisphere. S. noctilio can kill pine trees by injecting a pathogenic fungus, Amylostereum areolatum Boidin along with a phytopathogenic venom. The larvae live within the living wood layer of its host trees and adults congregate at the upper canopy level for mating. Extensive research has been directed toward the development of management strategies, including biological control. Ibalia leucospoides (Hymenoptera: Ibaliidae) is a larval parasitoid that has been widely introduced as a biological control agent for the invasive woodwasp in the Southern Hemisphere. Semiochemical-based lures, some of the most effective tools for detection of invasives, are not well developed for S. noctilio. In this study, the chemistry of attractive components of A. areolatum volatiles to both S. noctilio and I. leucospoides females was identified and evaluated in the laboratory and field. A female-produced sex pheromone, 10-oxo-decanoic acid, was discovered for S. noctilio which was attractive in laboratory assays. In addition, laboratory assays demonstrated a multi-component sex pheromone for I. leucospoides, produced by females. Understanding insect behavior and semiochemistry will lead to the development of lures, and this will open up new opportunities in S. noctilio management.