An Assessment of Nysius wekiuicola Populations and Thermal Microhabitat Conditions on Cinder Cones of the Maunakea Volcano, Hawai‘i
Date
2018-02
Authors
Contributor
Advisor
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Narrator
Transcriber
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
The endemic Hawaiian wēkiu bug (Nysius wekiuicola) is a carnivorous scavenger that only inhabits volcanic cinder cones above ~3,500 m elevation on the mountain, Maunakea, Hawai‘i. As a species of conservation concern threatened by invasive species, climate change, and habitat alteration, a greater understanding of wēkiu bug populations and habitat use through time is needed to inform habitat restoration efforts and conservation management decisions. In this study, locations on a high elevation and a lower elevation cinder cone were sampled using attractant traps in a buffered random design six times from June 2016- 2017 to examine wēkiu bug distribution patterns within cinder cone habitats and across seasons. A generalized linear mixed model (GLMM) was used to explore the relative importance of cinder cone characteristics (topographic aspect, surficial minerals, and elevation) hypothesized to influence wēkiu bug distributions. Additionally, thermal conditions were described and compared within the insects’ habitat (within 2-30 cm depth of cinder substrate). Results indicate that wēkiu bugs had a highly aggregated distribution, with up to 40 times higher bug densities at the higher elevation cinder cone, and the density of bugs changed within and between cinder cones throughout the year. Our GLMM indicated that sample month, topographic aspect, and elevation on a cinder cone influences wēkiu bug distributions with abundance increasing with elevation within a cinder cone, and the highest captures are predicted to be on the northeast aspects of the higher elevation cinder cone year-round. Temperature data shows multiple microclimates exist throughout cinder cone habitats at any given time, and the ash substrate layer could provide an important habitat refuge for the wēkiu bug, as this layer rarely freezes. We recommend preserving contiguous cinder cone habitats for the persistence of the wēkiu bug, and monitoring populations in a random sample design in known or restored habitats to effectively monitor wēkiu bug densities.
Description
Keywords
Conservation biology, Wildlife management, Entomology, Alpine Stone Desert, Cinder Cones, Habitat Restoration, Maunakea, Microhabitat, Wēkiu bug
Citation
Extent
112 pages
Format
Geographic Location
Time Period
Related To
Related To (URI)
Table of Contents
Rights
All UHH dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Rights Holder
Local Contexts
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.