A minimalist approach to the effects of density-dependent competition on insect life-history traits
A minimalist approach to the effects of density-dependent competition on insect life-history traits
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DOI：
10.1046/j.1365-2311.2002.00430.x
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发表时间：
2002-08-01
影响因子：
2.2
通讯作者：
Michalakis, Y
中科院分区：
文献类型：
--
作者：
Agnew, P;Hide, M;Michalakis, Y
1.密度依赖型竞争对生活史性状的表型和基因型表达具有重要影响，是调节种群生长的重要因素。特别是对于昆虫来说，幼虫之间依赖密度的竞争通常与幼虫死亡率增加、成熟延迟和成虫尺寸减小有关。这里报告的工作的目的是测试是否建立的表型效应的密度依赖性竞争的生活史性状可以复制在一个实验设计，需要最少数量的个人。埃及伊蚊的幼虫饲养密度的一个，两个，或三个人每个标准果蝇小瓶和六个不同的条件下幼虫的食物供应。这种设计要求每个独立重复相对较少的个体，并包括对照处理，其中以每瓶一只幼虫的密度饲养的个体与其他幼虫没有密度依赖性的相互作用。幼虫密度的增加或食物供应的减少导致幼虫死亡率的增加、化蛹的延迟以及在较短时间内饿死的较小的成虫的出现（指示营养储备较少的出现）。雌蚊比雄蚊相对较大（以翅长来衡量），但雄蚊往往存活更长时间。这些差异增加幼虫的食物供应增加，这两个性状的相对重要性，每一个性别的健身。特别强调了营养储备对男性生殖成功的作用。这种最低限度的方法可能会提供一个有用的模型，研究密度依赖的竞争对昆虫生活史性状的影响。
1. Due to its effects on the phenotypic and genotypic expression of life-history traits, density-dependent competition is an important factor regulating the growth of populations. Specifically for insects, density-dependent competition among juveniles is often associated with increased juvenile mortality, delayed maturity, and reduced adult size.2. The aim of the work reported here was to test whether the established phenotypic effects of density-dependent competition on life-history traits could be reproduced in an experimental design requiring a minimal number of individuals. Larvae of the mosquito Aedes aegypti were reared at densities of one, two, or three individuals per standard Drosophila vial and in six different conditions of larval food availability. This design required relatively few individuals per independent replicate and included a control treatment where individuals reared at a density of one larva per vial experienced no density-dependent interactions with other larvae.3. Increased larval densities or reduced food availability led to increased larval mortality, delayed pupation, and the emergence of smaller adults that starved to death in a shorter time (indicating emergence with fewer nutritional reserves).4. Female mosquitoes were relatively larger than males (as measured by wing length) but males tended to survive for longer. These differences increased as larval food availability increased, indicating the relative importance of these two traits for the fitness of each sex. The role of nutritional reserves for the reproductive success of males was highlighted in particular.5. This minimalist approach may provide a useful model for investigating the effects of density-dependent competition on insect life-history traits.