Diapause in the boll weevil (Coleoptera : Curculionidae) : Life-stage sensitivity to environmental cues
Diapause in the boll weevil (Coleoptera : Curculionidae) : Life-stage sensitivity to environmental cues
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DOI：
10.1093/aesa/92.3.396
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发表时间：
1999-05
影响因子：
2.3
通讯作者：
T. Wagner;E. Villavaso;J. Willers
中科院分区：
文献类型：
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作者：
T. Wagner;E. Villavaso;J. Willers
本研究考察了密西西比州北部田间和模拟田间环境下自然发生的棉铃象鼻虫的滞育反应。在七月、八月和九月收集了含有早期象鼻虫的方块，并将每组的子样本安装到实验室中类似的动态环境中。通过这种方式，一些象鼻虫在田间和实验室（对照）之间经历了不间断的光周期和温度，而其他象鼻虫在田间和实验室（处理）之间经历了时间上的向前或向后的转变。结果表明，在生命早期阶段，个体对滞育诱导或避免日长和温度的选择性敏感性独立于后期阶段，而在晚期阶段（包括成年）则独立于早期阶段。例如，一些个体似乎主要在生命早期或晚期阶段敏感，并且根据这些时候收到的环境线索，他们可能会也可能不会在成年后形成滞育表型。然而，获得滞育的增益或损失速率取决于部分或全部生命周期期间象征刺激的强度和持续时间。如果在整个生命周期中持续提供适当的线索，那么滞育在种群中的表达将最大化。任何时候提示的改变都会增加或减少滞育象鼻虫的百分比，其相对效果与原始刺激的强度和持续时间有关。一旦达到了滞育诱导刺激的阈值，人们似乎对环境变化的反应更加敏感。这些结果可以解释研究中滞育观察到的一些变异性。
This study examines the diapause response in naturally occurring boll weevils under field and simulated field environments of north Mississippi. Squares containing early-stage weevils were collected in July, August, and September and subsamples from each group were installed into similar dynamic environments in the laboratory. In this manner, some weevils experienced uninterrupted photoperiods and temperatures between the field and laboratory (controls), and others experienced a shift forward in time or backward in time between the field and laboratory (treated). Results indicate selective sensitivity among individuals to diapause-inducing or averting daylengths and temperatures during early life stages independent of later stages and during late stages (including adults) independent of earlier stages. For example, it appears that some individuals are sensitive primarily during the early or late life stages, and depending on the environmental cues received at these times, they may or may not develop the diapause phenotype as adults. However, the rates of gain or loss in the acquisition of diapause depend on the intensity and duration of the token stimuli during part or all of the life cycle. If the proper cues are sustained throughout the life cycle, then the expression of diapause in the population will be maximized. Alteration in cues at any time will increase or decrease the percentage of weevils in diapause, with the relative effect related to the intensity and duration of the original stimuli. Once they receive a threshold to diapause-inducing stimuli, populations appear to be more responsive to environmental change. These results may explain some of the variability observed in diapause among studies.