Building design, maintenance, and management can have significant impacts on accessibility and suitability for pest species. The brown marmorated stink bug, Halyomorpha halys (Stål), causes household nuisance pest problems because of its habit of using human homes as winter refuges. Studies were conducted to understand behaviors and characteristics relevant to this problem, including response to gravity, ability to pass through openings, responses to heat, and mortality estimations in wall assemblies. In the lab, winter shelter seeking bugs were shown to exhibit upward movement, and field observations of bugs on building exteriors gave similar results. In experiments testing the size limits on openings through which bugs could pass, height limited tests excluded most females at 4 mm, and all bugs at 3 mm. Pronotum width limited tests excluded most females at 8 mm and nearly all bugs at 7 mm. Accompanying measurements of over 900 bugs found an average female pronotum width of 8.33 mm and height of 4.03 mm, and male pronotum width of 7.47 mm and height of 3.50 mm, with minimum sizes indicating that only a small percentage of bugs will pass the smallest openings tested. Heat response experiments of shelter seeking bugs were first piloted outdoors, and then modified to be a forced choice indoor test. In outdoor tests on a flat plane wall section with alternating heated sections, bugs did not respond to thermal contrast but rather immediately walked off of the wall. In the indoor forced choice test, a box of four cavity walls was used. Bugs did not respond to the heated sections in either the adjacent or opposite configuration. Thermal simulation modeling was used to evaluate the possible effects of varying wall assembly materials and configurations on cold-related mortality of bugs overwintering in the cavity space behind cladding. Simulation results indicated that bugs electing to overwinter in the space between cladding and sheathing were at risk of freezing deaths, with mortality expectations increasing in better insulated buildings. The results of these studies will inform future control measures and impact studies in buildings. / Ph. D. / Building design, maintenance, and management can have significant impacts on accessibility and suitability for pest species. The brown marmorated stink bug, Halyomorpha halys (Stål), is a household pest because of its habit of using human homes as winter refuges. This research investigated the ability of these bugs to enter homes, and what happens once inside. This included responses to gravity and heat, studies of the body size and the ability to enter openings in building envelopes, and estimations of mortality due to freezing in wall assemblies using thermal simulation modeling. Bugs were shown in the laboratory and on the sides of buildings to consistently move upward. Bugs were given the ability to move along alternatingly heated and unheated sections of walls in search of winter shelter. The heated sections of walls did not elicit any response, suggesting that warmer portions of walls are not impacting the search for structure entrances. Bugs were shown to not pass through 3 mm tall or 7 mm wide openings, though female bugs tend to require even larger holes. Males are consistently smaller than females, at an average of 3.50 mm tall and 7.47 mm wide to the females’ average 4.03 mm height and 8.33 mm width. Thermal simulation modeling suggested that increasing the insulation in a building may influence the expected mortality rate of bugs that overwinter in the space between sheathing and cladding. These findings will help to create and target pest control methods, by helping design exclusion methods, identifying what openings need treatment, and indicating better orientations of traps. The thermal modeling results suggest possible effects of building design choices on the spread of H. halys, as well as possible problems associated with increased mortality within wall assemblies.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/82844 |
| Date | 17 April 2018 |
| Creators | Chambers, Benjamin Daniel |
| Contributors | Myers-Lawson School of Construction, Pearce, Annie R., Kuhar, Thomas P., Reichard, Georg, Leskey, Tracy C. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Dissertation |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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