Effect of elevated atmospheric CO2 on oviposition behavior in Manduca sexta moths
Effect of elevated atmospheric CO2 on oviposition behavior in Manduca sexta moths
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DOI：
10.1111/j.1365-2486.2005.00989.x
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发表时间：
2005-08-01
影响因子：
11.6
通讯作者：
Hildebrand, JG
中科院分区：
文献类型：
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作者：
Abrell, L;Guerenstein, PG;Hildebrand, JG
飞蛾能够以极高的灵敏度检测环境二氧化碳 (CO2) 的变化，但二氧化碳在这些昆虫和其他昆虫的生物学中的作用尚不清楚。尽管二氧化碳已被证明会影响螟蛾 Cactoblastis cactorum 的产卵（产卵）行为和天蛾 Manduca sexta 的花蜜觅食，但有关二氧化碳在这些物种的行为生物学中的一般作用的信息仍然缺乏。为了正确评估环境中温室气体水平的稳步上升可能如何改变不同物种的行为，需要比较数据。在生物圈 2 号中进行的实验探讨了环境二氧化碳水平的变化是否对六角蛾的产卵行为产生影响。在第一个系列的实验中，在飞行笼内测量了产卵情况，其中二氧化碳浓度接近环境水平或升高（400、800 或 1200 ppm）。对于每个浓度，用作产卵场所的寄主植物都是在与飞行笼内环境相匹配的二氧化碳水平下从种子中生长出来的。在同质二氧化碳水平下，我们观察到在测试浓度下产卵行为没有显着差异。在第二个系列的实验中，两组寄主植物被组装在飞行笼内，每组寄主植物都被一个微型自由空气二氧化碳富集（FACE）环包围。在这个选择测试中，一组测试植物周围产生了人为高二氧化碳的动态羽流，而第二组（对照组）周围释放了环境二氧化碳。对两个植物群的卵进行计数后，雌性 M. sexta 对在对照植物上产卵表现出较小的偏好。因此，与在类似动态流动条件下测试的 C. cactorum 雌性相比，M. sexta 雌性产卵并未受到 CO2 升高的强烈抑制。为了进一步研究这一现象，我们使用电生理记录，发现 M. sexta 中的 CO2 受体细胞与 C. cactorum 中的细胞不同，不容易受到环境 CO2 水平升高的影响。因此，这些发现表明，CO2 背景水平升高对 M. sexta 的 CO2 检测系统生理学的影响程度小于 C. cactorum，这与在环境 CO2 水平升高的情况下观察到的两个物种之间产卵行为的差异很好地相关。 C. cactorum 的寄主植物是景天类酸代谢植物，在分支表面产生夜间二氧化碳汇，而 M. sexta 寄主植物是呼吸性 CO2 的夜间来源。我们假设，全球环境二氧化碳水平的突然持续增加将不同程度地改变飞蛾的行为和生理机能，这些飞蛾利用二氧化碳汇和源作为感官线索来寻找寄主植物。
Moths can detect changes in environmental carbon dioxide (CO2) with extremely high sensitivity, but the role of CO2 in the biology of these and other insects is not well understood. Although CO2 has been demonstrated to influence egg-laying (oviposition) behavior of the pyralid moth Cactoblastis cactorum and nectar foraging of the sphingid moth Manduca sexta, information about the generalized role of CO2 in the behavioral biology of these species is lacking. Comparative data are necessary to properly assess how the behaviors of different species may be modified by steadily rising levels of greenhouse gases in the environment. Experiments carried out in Biosphere 2 addressed whether changes in ambient CO2 levels play a role in the oviposition behaviors of M. sexta moths. In the first series of experiments, oviposition was measured inside a flight cage with different levels of nearly ambient or elevated CO2 (400, 800 or 1200 ppm). For each concentration, hostplants used as oviposition sites were grown from seed at a CO2 level that matched the environment inside the flight cage. Under homogenous levels of CO2, we observed no significant difference in oviposition behavior at the concentrations tested. In a second series of experiments, two groups of hostplants, each surrounded by a mini free-air CO2 enrichment (FACE) ring, were assembled inside a flight cage. In this choice test, a dynamic plume of artificially high CO2 was generated around one group of test plants, while ambient CO2 was released around the second (control) group. After eggs were counted on both plant groups, M. sexta females showed a small preference for ovipositing on the control plants. Therefore, in contrast to C. cactorum females tested under similar dynamic flow conditions, M. sexta female oviposition was not strongly inhibited by elevated CO2. To investigate this phenomenon further, we used electrophysiological recording and found that the CO2 receptor cells in M. sexta, unlike those in C. cactorum, are not readily affected by elevated levels of ambient CO2. These findings therefore suggest that elevated background levels of CO2 affect the physiology of the CO2 detection system of M. sexta to a lesser extent than that of C. cactorum, and this correlates well with the observed differences in oviposition behavior between the two species under elevated levels of environmental CO2. Hostplants of C. cactorum are crassulacean acid metabolism plants that generate nocturnal CO2 sinks on the cladode surfaces, whereas, M. sexta hostplants are nocturnal sources of respiratory CO2. We hypothesize that the abrupt and continuing increase in global ambient CO2 levels will differentially alter the behavior and physiology of moths that use CO2 sinks and sources as sensory cues to find hostplants.