Thesis
Efficacy of Nanophyes marmoratus Goeze (Coleoptera: brentidae) attack on Lythrum salicaria L. (Lythraceae) seed production and population dynamics in Eastern Washington
Washington State University
Master of Science (MS), Washington State University
2013
Handle:
https://hdl.handle.net/2376/106089
Abstract
Purple loosestrife, Lythrum salicaria, was first recorded in Washington State in 1929. This Eurasian native was originally introduced into the United States for aesthetic purposes. However, L. salicaria quickly became an invasive pest of wetlands and water bodies. Purple loosestrife outcompetes indigenous plants and does not provide food or shelter for native fauna. A series of exotic biological control agents were released beginning in 1991 to control this plant. Two chrysomelid beetles in the genus Galerucella were able to greatly reduce the numbers of L. salicaria in Washington State, but this caused researchers to overlook the impact of a third released agent- Nanophyes marmoratus. Nanophyes marmoratus, a member of the family Brentidae in the order Coleoptera, attacks the flower buds of L. salicaria in the larval stage, and is the only late season insect to feed on the plant. To get a better understanding of how N. marmoratus impacts L. salicaria in the state, plant populations were assessed at three sites near Moses Lake in eastern WA. At each site, a 50 m long transect was established and plants were v sampled every two weeks for three months. Each sample was analyzed for the presence of N. marmoratus. When the beetles are present they can completely eliminate seed output of infested buds. The beetles were found to infest up to 26% of all buds on an individual plant and were more likely to infest shorter inflorescence spikes than longer ones. A potential explanation for this outcome could be due to an avoidance behavior. Although there were not many incidences of predation or parasitism recorded, there could be some as yet undetectable variable that prevents N. marmoratus populations from attaining larger densities.
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Details
- Title
- Efficacy of Nanophyes marmoratus Goeze (Coleoptera: brentidae) attack on Lythrum salicaria L. (Lythraceae) seed production and population dynamics in Eastern Washington
- Creators
- Ryan James Rayl
- Contributors
- Richard Stanly Zack (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
- 99900525116201842
- Language
- English
- Resource Type
- Thesis