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Evidence for regional variation in the thermal biology of Dendroctonus rufipennis (Kirby) (Coleoptera: Curculionidae, Scolytinae) in Colorado

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dc.contributor.authorDell, Isaac Hans, author
dc.contributor.authorDavis, Seth, advisor
dc.contributor.authorKondratieff, Boris, committee member
dc.contributor.authorRedmond, Miranda, committee member
dc.contributor.authorStephens, Sky, committee member
dc.date.accessioned2019-01-11T16:05:21Z
dc.date.available2020-01-08T16:05:19Z
dc.date.issued2018
dc.description.abstractDendroctonus rufipennis (Kirby) (Coleoptera: Curculionidae, Scolytinae), the spruce beetle, is native to the forests of western North America where it is the primary cause of Engelmann spruce Picea engelmannii Parry ex Engelm. mortality. This study is an effort to further the knowledge of ecological conditions that affect D. rufipennis flight phenology, abundance, and fitness traits. Spruce beetle populations were monitored for two years at high elevation spruce forest sites; during this period of time 32,881 spruce beetles were captured, as well as significant quantities of off-target species. Trapping sites were classified by variation in thermal trends using hierarchical cluster analysis which revealed statistical support for two groups of sites (cold' and 'warm'). A logistic function was used to model cumulative proportion of trap capture by day-of-year for all sites; and modeled phenologies indicated that beetles from cold sites terminate their flight period significantly earlier than beetles from warm sites. Additionally, the flight season is prolonged at warm sites, suggesting that hosts at warmer sites are exposed to beetle pressure for longer periods of time. At higher latitudes, the flight period was significantly longer than at lower latitudes, but there was no relationship between spruce beetle flight phenology and elevation. There was a significant female bias in the sex ratio at cold sites, but sex ratios were even at warm sites. Fitness traits (body size) varied along both latitudinal and elevational gradients; a negative correlation between elevation and pronotal width was observed indicating that beetles were smaller at high elevations, but beetles tended to be larger at high latitudes. Correlations between spruce beetle abundances in traps and the abundances of predators and competitors were evaluated, but there was no evidence that either feeding guild was negatively impacting spruce beetle abundances. The results of this study suggest that fine scale environmental variation must be considered when managing or monitoring spruce beetle populations, as both site-level thermal variability and latitude are associated with variation in the flight period and corresponding biotic pressure on host trees.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.identifierDell_colostate_0053N_15196.pdf
dc.identifier.urihttps://hdl.handle.net/10217/193249
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relation.ispartof2000-2019
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.titleEvidence for regional variation in the thermal biology of Dendroctonus rufipennis (Kirby) (Coleoptera: Curculionidae, Scolytinae) in Colorado
dc.typeText
dcterms.embargo.expires2020-01-08
dcterms.embargo.terms2020-01-08
dcterms.rights.dplaThis Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
thesis.degree.disciplineForest and Rangeland Stewardship
thesis.degree.grantorColorado State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (M.S.)

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