Thesis
The effects of environmental factors on the phenology and abundance of overwintered Eustenopus villosus and Larinus curtus (Coleoptera: Curculionidae) on Centaurea solstitialis in Washington state
Washington State University
Master of Science (MS), Washington State University
12/2015
Handle:
https://hdl.handle.net/2376/103121
Abstract
The phenology and abundance of overwintered Eustenopus villosus (Boheman) and Larinus curtus (Hochhut) in relation to phenology of Centaurea solstitialis L. (Asteraceae: Cardueae) and environmental factors were studied in eastern Washington State in 2014 and 2015. Phenological development of C. solstitialis, ambient and soil temperatures, soil moisture, relative humidity, and abundance of E. villosus and L. curtus were recorded weekly or bi-weekly between early May when overwintered adults began to appear on C. solstitialis through mid-August when the last of the overwintered beetles had died. Three distinct phases of activity were evident for overwintered adults of both weevil species in 2014 and 2015. In phase one (pre-appearance phase) neither species was detected. Phase two represented the initial appearance and population increase of both weevil species. Phase three represented the decline in the abundance of both weevil species. In both 2014 and 2015 phenology of E. villosus was most highly correlated with increasing ambient temperature. In contrast, the phenology of overwintered L. curtus adults in 2014 was most correlated with increasing C. solstitialis cover and in 2015 with increasing ambient temperature. The decline phases of E. villosus adults were most correlated with phenological stages of C. solstitialis beyond the most advanced budding stage in both 2014 and 2015. The decline in abundance of overwintered L. curtus adults in 2014 was most correlated with C. solstitialis cover and in 2015 with advancing C. solstitialis phenological stages beyond the most advanced budding stage. This pattern of correlation indicates that the appearance of overwintered E. villosus and L. curtus adults and colonization of C. solstitialis are primarily influenced by ambient temperature, and that population decline of both species is likely a function of the weevils' completing their lifecycle. This latter phase has been shown in other studies to be synchronized with the phenology of C. solstitialis.
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Details
- Title
- The effects of environmental factors on the phenology and abundance of overwintered Eustenopus villosus and Larinus curtus (Coleoptera: Curculionidae) on Centaurea solstitialis in Washington state
- Creators
- Steven Edward Woodley
- Contributors
- Benjamin A. Zamora (Chair)Richard Stanly Zack (Committee Member) - Washington State University, Entomology, Department ofMark Swanson (Committee Member) - Washington State University, Environment, School of the (CAHNRS)
- Awarding Institution
- Washington State University
- Academic Unit
- Environment, School of the (CAHNRS)
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Number of pages
- 37
- Identifiers
- 99900525058901842
- Language
- English
- Resource Type
- Thesis