Thesis
Evaluating the toxicity of candidate organic and conventional insecticides on Western grape leafhopper (Erythroneura elegantula) and Virginia creeper leafhopper (Erythroneura ziczac) (Hemiptera: cicadellidae) under vineyard and laboratory conditions
Washington State University
Master of Science (MS), Washington State University
2016
Handle:
https://hdl.handle.net/2376/101028
Abstract
Wine grape production has doubles in Washington State over the past 20 years with over 20,000 Ha in 2016. Simultaneously consumer demand for organic products has increased. Controlling leafhopper pests with organically acceptable methods has proved to be a major obstruction in the production of organically certified wine grapes. Routine outbreaks have resulted in substantial economic loss. With improved and organically approved methods for leafhopper control more wine grape growers would choose to produce wine grapes in organic certification programs. The western grape leafhopper (Erythroneura elegantula Osborn 1928) and the Virginia creeper leafhopper (Erythroneura ziczac Walsh 1862) are the two leafhopper pests frequently observed in Washington State vineyards. Herein, we vineyard-tested the efficacy of several candidate bio-insecticides and conventional insecticides against E. elegantula and E. ziczac leafhoppers. This study included the initial testing of several alternative candidate insecticides for leafhopper control. Controlled laboratory bioassays also were completed, and the LC50 and LC90 were calculated for the non-systemic insecticides tested. Of the bio-insecticides tested, pyrethrum (Pyganic TM) was the only product that provided effective control of leafhoppers in both the vineyard and laboratory components of this study. In vineyard efficacy tests all the conventional insecticides significantly (P<0.05) reduced leafhopper abundance compared to untreated controls. Flupyridifurone (SivantoTM) was the most efficacious of the conventional insecticides tested and the only insecticide that provided 100% mortality of leafhoppers in the vineyard. We demonstrated that organic viticulturists could apply pyrethrum to control outbreaks of E. ziczac. We also demonstrated that there are several effective conventional insecticides that can be added to conventional vineyard Integrated Pest Management programs in Washington State.
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Details
- Title
- Evaluating the toxicity of candidate organic and conventional insecticides on Western grape leafhopper (Erythroneura elegantula) and Virginia creeper leafhopper (Erythroneura ziczac) (Hemiptera: cicadellidae) under vineyard and laboratory conditions
- Creators
- Jonathan Scott O'Hearn
- Contributors
- Douglas B. Walsh (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Entomology, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525298901842
- Language
- English
- Resource Type
- Thesis