Feasibility of establishing a tritrophic pest management system in the greenhouse industry: An approach to utilization of pathogenic fungi for control of western flower thrips, and pathogenic fungi with predators for synergistic control of cabbage looper

Western flower thrips (WFT), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), and cabbage looper, Trichoplusia ni Hubner (Lepidoptera: Noctuidae), are both serious agricultural and horticultural pests.; Beauveria bassiana (Balsamo) Vuillemin is an important ubiquitous entomopathogen. The main goal of this thesis was to test several isolates of B. bassiana, isolated from insects and soil in Alberta, Canada against WFT and cabbage looper including its natural predator Podisus maculiventris (Say) (Hemiptera: Pentatomidae).; A whole-insect bioassay system clearly demonstrated the inter- and intra-strain variability in effectiveness inherent to all B. bassiana strains tested herein.; Four isolates, 3, 7, 25 and 35 performed better than the commercially available B. bassiana-based mycoinsecticide, Emerald BioAgriculture's isolate GHA, when tested against adult female WFT in replicated, comparative, whole-insect bioassays. Isolate 3 also performed better than GHA when tested on cabbage looper, and resulted in a synergistic effect if used in conjunction with P. maculiventris. These strains of B. bassiana demonstrate commercial potential as biological control agents.