Department of Entomology, Purdue University, West Lafayette, Indiana, United States of America.
PLoS One. 2019 Feb 7;14(2):e0211677. doi: 10.1371/journal.pone.0211677. eCollection 2019.
The global population growth of the bed bug, Cimex lectularius (L.), is attributed to their cryptic behavior, diverse insecticide resistance mechanisms, and lack of public awareness. Bed bug control can be challenging and typically requires chemical and non-chemical treatments. One common non-chemical method for bed bug management is thermal remediation. However, in certain instances, bed bugs are known to survive heat treatments. Bed bugs may be present after a heat treatment due to (i) abiotic factors associated with the inability to achieve lethal temperatures in harborage areas for a sufficient time period, (ii) re-infestation from insects that escaped to cooler areas during a heat treatment or (iii) development of physiological resistance that allows them to survive heat exposure. Previous research has investigated the optimal temperature and exposure time required for either achieving complete mortality or sublethally affecting their growth and development. However, no research has examined bed bug populations for their ability to develop resistance to heat exposure and variation in thermo-tolerance between different bed bug strains. The goals of this study were: i) to determine if bed bugs could be selected for heat resistance under a laboratory selection regime, and ii) to determine if bed bug populations with various heat exposure histories, insecticide resistance profiles, and geographic origins have differential temperature tolerances using two heat exposure techniques (step-function and ramp-function). Selection experiments found an initial increase in bed bug survivorship; however, survivorship did not increase past the fourth generation. Sublethal exposure to heat significantly reduced bed bug feeding and, in some cases, inhibited development. The step-function exposure technique revealed non-significant variation in heat tolerance between populations and the ramp-function exposure technique provided similar results. Based on these study outcomes, the ability of bed bugs to develop heat resistance appears to be limited.
全球臭虫（Cimex lectularius（L.））的种群增长归因于它们的隐匿行为、多样化的杀虫剂抗性机制以及公众意识的缺乏。臭虫的控制可能具有挑战性，通常需要进行化学和非化学处理。一种常见的非化学臭虫管理方法是热修复。然而，在某些情况下，已知臭虫能够在热处理后存活。在热处理后，臭虫可能会出现，原因有三：（i）由于在藏匿区无法达到足够致死温度的非生物因素，导致处理时间不够长；（ii）来自在热处理过程中逃到较冷区域的昆虫的再侵扰；（iii）发展出允许它们在热暴露下存活的生理抗性。先前的研究已经调查了实现完全致死或亚致死影响其生长和发育所需的最佳温度和暴露时间。然而，没有研究检查臭虫种群对热暴露的抗性发展以及不同臭虫株之间耐热性的变化。本研究的目的是：i）确定臭虫是否可以在实验室选择方案下选择耐热性，以及 ii）使用两种热暴露技术（阶跃函数和斜坡函数）确定具有不同热暴露史、杀虫剂抗性谱和地理起源的臭虫种群是否具有不同的温度耐受性。选择实验发现臭虫的存活率最初有所增加；然而，在第四代之后，存活率并没有增加。亚致死热暴露显著降低了臭虫的取食能力，在某些情况下还抑制了其发育。阶跃函数暴露技术表明种群之间的耐热性没有显著差异，斜坡函数暴露技术也提供了类似的结果。根据这些研究结果，臭虫发展耐热性的能力似乎是有限的。
