There is a growing evidence that consistent interindividual differences in behavior, that is, behavioral types, can play an important role in key ecological processes such as predator–prey interactions, which in turn can have direct implications on biological control. Behavioral types of generalist predators may affect these interactions through individual differences in predators’ prey preferences and the breadth of predators’ trophic niches. This study examined how the multivariate nature of behavior, namely foraging aggressiveness, activity level, and risk-taking behavior, determines prey selection and trophic niche of the generalist agrobiont spider Philodromus cespitum. In laboratory experiments, we determined the repeatability of these behaviors and the preference between crickets, moths, fruit flies, and collembolans. We found that all three behaviors were moderately to strongly repeatable but there were no correlations between them, thus they did not form a behavioral syndrome. Only foraging aggressiveness influenced the prey selection of philodromid spiders and the more aggressive individuals had wider trophic niches because they incorporated prey that were more difficult to capture in their diet. In addition, more aggressive individuals killed a greater quantity of particular prey types while other prey types were killed at a similar rate by both aggressive and nonaggressive individuals. The differences in philodromids’ foraging aggressiveness, therefore, affected not only the overall prey density but also resulted in different prey community composition. As pest density and composition can both affect crop performance, further research needs to investigate how the interindividual behavioral differences of generalist natural enemies cascade down on the crops.

中文翻译：

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觅食的侵略性决定了通才生物控制物种的营养生态位。

越来越多的证据表明，行为上一致的个体间差异（即行为类型）在诸如捕食者与猎物之间的相互作用等关键生态过程中可以发挥重要作用，而这反过来又可能对生物控制产生直接影响。通才型捕食者的行为类型可能会通过捕食者偏好的个体差异和捕食者营养小生境的广度来影响这些互动。这项研究检查了行为的多元性质，即觅食的侵略性，活动水平和冒险行为，如何确定通才的农用生物蜘蛛Philodromus cespitum的猎物选择和营养位。在实验室实验中，我们确定了这些行为的可重复性，以及determined，飞蛾，果蝇和collembolans之间的偏好。我们发现，这三种行为均具有中等至强烈可重复性，但它们之间没有相关性，因此它们没有形成行为综合症。只有觅食的侵略性会影响嗜食性蜘蛛的猎物选择，而更具攻击性的个体则具有较宽的营养位，因为它们掺入了在饮食中更难捕获的猎物。此外，攻击性更强的个人杀死了大量特定类型的猎物，而攻击性和非攻击性个人以相似的比率杀死了其他猎物。因此，嗜线虫的觅食攻击力有所不同，不仅影响了整个猎物的密度，而且导致了不同的猎物群落组成。由于害虫的密度和成分都可能影响农作物的生长，因此需要进一步的研究来研究通才天敌的个体行为差异如何在农作物上逐步下降。