Dissertation
Ecology, biology, and management of wireworms (Coleoptera: Elateridae) in Pacific Northwest cereal crops
Doctor of Philosophy (PhD), Washington State University
01/2015
Handle:
https://hdl.handle.net/2376/118196
Abstract
Wireworms, the soil-dwelling larvae of click beetles (Coleoptera: Elateridae), have re-emerged as significant pests of cereal crops in the Pacific Northwestern United States. Wireworms are difficult to manage because their movement through different soil depths makes accurate in-season sampling difficult, and significant damage can be done to crops before wireworms are identified and management strategies are implemented. The overall aim of this research study was to improve our knowledge of the biology and ecology of wireworms so more effective integrated pest management strategies can be developed. In Chapter 1 we provide a broad overview of wireworms and their impacts in cropping systems. Subsequent chapters then focused on the specifics of Pacific Northwest cropping systems. In Chapter 2 we conducted a large-scale survey to examine the distribution and ecology of wireworm species in the Pacific Northwest cereal fields. This survey revealed 13 different wireworm species, collected in samples taken from 160 fields distributed across 20 counties in Washington, Oregon, and Idaho. Three species, Limonius infuscatus, L. californicus, and Selatosomus pruininus represented approximately 90% of wireworms collected. The dominant species detected varied across counties, indicating that landscapes and climate factors play a major role in species distribution. In Chapter 3 we examined the differences in seasonal population dynamics of the two Limonius species. Our results show that as spring moves into summer L. californicus feeds more aggressively, whereas L. infuscatus is less aggressive and decreases in abundance as crop season progresses. These data indicate that management strategies need to be tailored to the species seasonal phenology so more effective control can be achieved. In Chapter 4 we investigated whether diverse wireworm communities are more impactful than single species at inflicting damage to wheat plants. Our results revealed that wireworms are more productive and cause considerably higher damage to crops if present as a single species in the field rather than as a multi-species complex. In particular, L. californicus and S. pruininus were highly impactful species, while L. infuscatus had significantly reduced impacts. Overall, our results suggest that management of wireworms needs to be tailored to the specific species present in a field.
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Details
- Title
- Ecology, biology, and management of wireworms (Coleoptera: Elateridae) in Pacific Northwest cereal crops
- Creators
- Ivan Milosavljevic
- Contributors
- David W Crowder (Advisor)Walter S Sheppard (Committee Member)Arron H Carter (Committee Member)Aaron D Esser (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Entomology, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 192
- Identifiers
- 99900581837501842
- Language
- English
- Resource Type
- Dissertation