Department of Entomology, University of Kentucky, Lexington, KY.
Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC.
J Econ Entomol. 2020 Dec 9;113(6):2858-2863. doi: 10.1093/jee/toaa250.
The common bed bug (Cimex lectularius L.) is an obligate hematophagous ectoparasite that has significant impacts on human health and well-being. All life stages of bed bugs (except eggs) feed solely on blood, which is required to molt and reproduce. Bed bugs use multiple cues to locate their hosts, including heat, CO2, and body odors. Of these cues, detection of heat appears limited to a short distance of <3 cm. However, it remains unclear if bed bugs can detect radiant heat, what structure(s) are responsible for heat detection, and if heat detection via the antennae is required for feeding. In this study, bed bug response to radiant heat was evaluated using the two-choice T-maze assay with the heat source either in contact with the surface (i.e., conduction) or not in contact (i.e., radiation) in nonantennectomized bed bugs. Further, we systematically ablated the bed bug's antennal segments (distal tip, first segment, and all four segments) and assessed their responses to heat and feeding in a unique two-choice T-maze assay and individual feeding assays, respectively. Our two-choice assays with contact to or no contact with the surface indicated that bed bugs cannot detect radiant heat. Later, we found that the distal tip of the terminal antennal segment is responsible for orientation toward a heat source. However, >50% of the bed bugs fed even when the entire antenna was removed, suggesting redundancy in sensory cues that drive feeding. These results will be used to better understand the role heat plays in bed bug host attraction and design of traps.
常见的臭虫（Cimex lectularius L.）是一种专性吸血外寄生虫，对人类健康和福祉有重大影响。臭虫的所有生命阶段（除了卵）都只以血液为食，这是蜕皮和繁殖所必需的。臭虫使用多种线索来定位它们的宿主，包括热量、CO2 和体臭。在这些线索中，对热量的检测似乎仅限于<3 厘米的短距离。然而，目前尚不清楚臭虫是否能检测到辐射热，哪些结构负责检测热量，以及是否通过触角进行热量检测是进食所必需的。在这项研究中，使用带有热源的双选择 T 迷宫试验评估了臭虫对辐射热的反应，热源与表面接触（即传导）或不接触（即辐射）在非触角切除的臭虫中。此外，我们系统地消融了臭虫的触角节段（末端尖端、第一节和所有四个节段），并在独特的双选择 T 迷宫试验和单独的进食试验中分别评估了它们对热和进食的反应。我们的带有接触或不接触表面的双选择试验表明，臭虫不能检测到辐射热。后来，我们发现末端触角节段的尖端负责朝向热源定向。然而，即使整个触角被移除，超过 50%的臭虫仍然进食，这表明驱动进食的感觉线索存在冗余。这些结果将用于更好地理解热在臭虫宿主吸引和陷阱设计中的作用。
