Maternal behaviours may explain riffle-scale variations in some stream insect populations
Maternal behaviours may explain riffle-scale variations in some stream insect populations
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母性行为可能解释了一些溪流昆虫种群的浅滩规模变化
DOI：
10.1111/fwb.12281
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发表时间：
2013
影响因子：
2.7
通讯作者：
Lancaster J
中科院分区：
文献类型：
--
作者：
Lancaster J
同一河流上的相似河道单元（浅滩）之间以及相似河流之间的幼虫昆虫的物种组成和丰度可能存在显着差异。这种变化的来源很大程度上无法解释，但很重要，因为这种空间变化可以影响人口和群落动态以及抽样方案的设计。一些水生昆虫的产卵和产卵行为是专门化的，卵产在特定的位置，这可能会影响溪流中卵和幼虫的空间分布。在相对较短的溪流长度（1公里）内，我们测试了产卵地点的数量是否影响整个河谷面积从80到460平方米的不同龄期幼虫的数量。我们研究了两种蜉蝣，即蜉蝣Baetis rhodani和石蛾Rhyacophila dorsalis，它们的幼虫是浅滩专家，成虫专门在浅滩的浮出岩石上产卵。为了进行比较，我们还检查了对照物种，黑蝇属，其幼虫也是浅滩专家，但成虫在尾随植被上产卵。作为替代假设，我们测试了每条浅滩幼虫的数量是否与栖息地可用性相关（通过浅滩面积测量）。 罗德尼安德R. 背侧鱼与每个浅滩的产卵地点数量呈正相关，但与浅滩区域无关。相比之下，早龄拟鱼（对照物种）的数量与任一预测变量均无关。对于后期龄期，浅滩面积是所有物种每浅滩幼虫数量的良好预测指标，尽管产卵地点的数量仍然可以解释 B 的许多变异。 罗德尼安德R. 背侧。这种分布模式的个体发生变化表明幼虫生活期间密度的调整，并且证据表明早期幼虫的密度依赖性死亡率。与水生昆虫幼虫数量的浅滩到浅滩的变化可以通过幼虫栖息地来解释的普遍观点相反，这项研究表明成虫行为的强烈影响，产卵地点的可用性可以解释某些物种的大量这种变化。这些结果挑战了关于水生昆虫种群的传统观点，水生昆虫种群的动态可能比之前认为的更加复杂和有趣。
Species composition and abundance of larval insects can vary significantly between similar channel units (riffles) on the same stream as well as between similar streams. The source of this variation is largely unexplained, but important because such spatial variations can influence population and community dynamics and the design of sampling programmes. The maternal and oviposition behaviours of some aquatic insects are specialised, such that eggs are laid in particular locations, and this could influence the spatial distribution of eggs and larvae within a stream.In a relatively short length of stream (1 km), we tested whether the number of oviposition sites influenced the number of larvae of different instars in whole riffles that ranged in area from 80 to 460 m2. We examined two species, a mayflyBaetis rhodaniand a caddisflyRhyacophila dorsalis, with larvae that are riffle specialists and adults that oviposit exclusively on emergent rocks in riffles. For comparison, we also examined a control species, blackfliesSimuliumspp., with larvae that are also riffle specialists, but adults that oviposit on trailing vegetation. As an alternative hypothesis, we tested whether the numbers of larvae per riffle were associated with habitat availability, as measured by riffle area.Numbers of early‐instarB. rhodaniandR. dorsaliswere positively associated with the numbers of oviposition sites per riffle, but not riffle areas. In contrast, numbers of early‐instarSimuliumper riffle (the control species) were not associated with either predictor variable. For later instars, riffle area was a good predictor of larval numbers per riffle for all species, even though the number of oviposition sites still explained much variation forB. rhodaniandR. dorsalis. This ontogenetic shift in distribution patterns suggests an adjustment of densities during larval life, and the evidence points to density‐dependent mortality of early‐instar larvae.Contrary to the prevailing view that riffle‐to‐riffle variations in the numbers of aquatic insect larvae can be explained by larval habitat, this study demonstrates a strong influence of adult behaviour, and oviposition site availability can explain significant amounts of this variation for some species. These results challenge traditional views about aquatic insect populations, which may have more complex and interesting dynamics than considered previously.