Host location in bed bugs is poorly understood. Of the primary host-associated cues known to attract bed bugs – CO2, odors, heat – heat has received little attention as an independent stimulus. We evaluated the effects of target temperatures ranging from 23 to 48°C on bed bug activation, orientation and feeding. Activation and orientation responses were assessed using a heated target in a circular arena. All targets heated above ambient temperature activated bed bugs (initiated movement) and elicited oriented movement toward the target, with higher temperatures generally resulting in faster activation and orientation. The distance over which bed bugs could orient toward a heat source was measured using a 2-choice T-maze assay. Positive thermotaxis was limited to distances <3 cm. Bed bug feeding responses on an artificial feeding system increased with feeder temperature up to 38 and 43°C, and declined precipitously at 48°C. In addition, bed bugs responded to the relative difference between ambient and feeder temperatures. These results highlight the wide range of temperatures that elicit activation, orientation and feeding responses in bed bugs. In contrast, the ability of bed bugs to correctly orient towards a heated target, independently of other cues, is limited to very short distances (<3 cm). Finally, bed bug feeding is shown to be relative to ambient temperature, not an absolute response to feeder blood temperature.
The authors declare no competing or financial interests.
Z.C.D. and C.S. designed the study and wrote the manuscript. Z.C.D. and R.M. performed the experiments. Z.C.D. analyzed the data.
This research was supported in part by the Blanton J. Whitmire endowment, the Pest Management Foundation of the National Pest Management Association, the US Department of Housing and Urban Development Healthy Homes program (NCHHU0017-13), the Alfred P. Sloan Foundation (2013-5-35 MBE), the National Science Foundation (IOS-1456973), and an award from the National Institute of Environmental Health Sciences (P30ES025128) to the Center for Human Health and the Environment. Z.C.D. was supported by the David R. Nimocks, Jr Fellowship and the North Carolina Pest Management Association Fellowship, and scholarships from the Entomological Society of America. Deposited in PMC for release after 12 months.
- Received May 20, 2016.
- Accepted September 14, 2016.
- © 2016. Published by The Company of Biologists Ltd