Variation in Larval Thermal Tolerance of Three Saproxylic Beetle Species
Variation in Larval Thermal Tolerance of Three Saproxylic Beetle Species
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DOI：
10.1093/ee/nvac091
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发表时间：
2022-11-08
影响因子：
1.7
通讯作者：
Yanoviak，Stephen P.
中科院分区：
文献类型：
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作者：
Lawhorn，Kane A.;Yanoviak，Stephen P.
温度是限制生物分布的关键非生物条件，森林昆虫对极端温度特别敏感。虽然有翅的成年昆虫通常能够逃离不利的温度，但其他不太灵活的昆虫（例如，幼虫）必须经受住当地的小气候条件才能生存。在这里，我们测量了幼虫的热耐受性的三个saperylytic甲虫种，是常见的居民粗木质残体（CWD）在北美东部的温带森林：Lucanus elaphusFabricius（Lucanidae），Dendroides canadensisLatreille（Pyrochroidae），andOdontotaenius disjunctusIlliger（Passalidae）。我们确定了它们的临界热最大值（CTmax）如何随体型（质量）而变化，并测量了代表这些物种所占据的微生境范围的CWD的热剖面。平均CTmax在三个物种之间存在差异，并且随着种内质量的增加而增加。然而，质量是不是一个很好的预测物种之间的耐热性。变温率和时间对幼虫的CTmax也有影响，但仅福特.加拿大龙属elaphus分别。相对干燥的CWD内的加热剖面有时超过甲虫幼虫的CTmax，CWD的较深部分通常较冷。CTmax的种间差异不能完全解释的微生境协会，但结果表明，在森林内的一些物种的分布可能会受到当地的极端温度。了解腐甲幼虫对栖息地变暖的反应将有助于预测气候变化和栖息地破碎化加剧下群落结构和生态系统功能的变化。
Temperature is a key abiotic condition that limits the distributions of organisms, and forest insects are particularly sensitive to thermal extremes. Whereas winged adult insects generally are able to escape unfavorable temperatures, other less-vagile insects (e.g., larvae) must withstand local microclimatic conditions to survive. Here, we measured the thermal tolerance of the larvae of three saproxylic beetle species that are common inhabitants of coarse woody debris (CWD) in temperate forests of eastern North America:Lucanus elaphusFabricius (Lucanidae),Dendroides canadensisLatreille (Pyrochroidae), andOdontotaenius disjunctusIlliger (Passalidae). We determined how their critical thermal maxima (CTmax) vary with body size (mass), and measured the thermal profiles of CWD representing the range of microhabitats occupied by these species. Average CTmaxdiffered among the three species and increased with mass intraspecifically. However, mass was not a good predictor of thermal tolerance among species. Temperature ramp rate and time in captivity also influenced larval CTmax, but only forD. canadensisandL. elaphusrespectively. Heating profiles within relatively dry CWD sometimes exceeded the CTmaxof the beetle larvae, and deeper portions of CWD were generally cooler. Interspecific differences in CTmaxwere not fully explained by microhabitat association, but the results suggest that the distribution of some species within a forest can be affected by local thermal extremes. Understanding the responses of saproxylic beetle larvae to warming habitats will help predict shifts in community structure and ecosystem functioning in light of climate change and increasing habitat fragmentation.