Factors influencing cannibalism in the wolf spider Pardosa agrestis (Araneae, Lycosidae)
Factors influencing cannibalism in the wolf spider Pardosa agrestis (Araneae, Lycosidae)
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DOI：
10.1007/s002650050570
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发表时间：
1999-04
影响因子：
2.3
通讯作者：
F. Samu;S. Toft;B. Kiss
中科院分区：
文献类型：
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作者：
F. Samu;S. Toft;B. Kiss
同类相食的倾向在蜘蛛中是众所周知的，并且可能是影响种群大小的一个重要因素。狼蛛，Pardosa agrestis，是中欧农业栖息地中占主导地位的非结网蜘蛛。初步的实地观察表明，延长生殖期，这导致在一个非常广泛的大小分布的少年龄期。我们假设，如果同类相食是由大小的差异，特别是在猎物稀少的时期，这些人口可能会受到同类相食的生态意义的方式。对juvenileP进行了实验室研究。Agrestisin arenas。我们分析了同类相食的以下几个具体方面：（1）对手之间的体重比的影响;（2）体重本身的影响;（3）饥饿程度在决定蜘蛛同类相食倾向中的作用。体重和饥饿的作用在单独的实验中进行了分析，在这两种情况下，通过控制另一个变量。结果表明，同类相食与体重比和饥饿度均呈强正相关，但个体的绝对大小/年龄不能预测同类相食事件的发生。这些实验产生了一个合理的假设，即同类相食可能是真实的种群调节中的一个重要现象，应该在未来的实地实验中专门测试这一假设。
Cannibalistic tendencies are well known in spiders and may be a significant factor influencing population size. The wolf spider,Pardosa agrestis, is the dominant non-web-building spider in a wide range of central European agricultural habitats. Preliminary field observations indicated an extended reproductive period, which results in a very wide size distribution of juvenile instars. We hypothesised that if cannibalism is enhanced by differences in size, especially during periods when prey is scarce, these populations might be susceptible to cannibalism in an ecologically significant way. Laboratory studies were conducted on juvenileP. agrestisin arenas. We analysed the following specific aspects of cannibalism: (1) the effect of the weight ratio between the opponents; (2) the effect of weight per se, and (3) the role of hunger level in determining cannibalistic tendencies of spiders. The role of weight and hunger were analysed in separate experiments, in both cases by controlling for the other variable. The results showed that cannibalism was strongly positively correlated with both weight ratio and hunger, but absolute size/age of an individual could not predict the occurrence of a cannibalistic event. These experiments generated the plausible hypothesis that cannibalism might be an important phenomenon in the regulation of real populations, which should be tested specifically in future field experiments.