Conservative biological control promotes the use of native natural enemies to limit the size and growth of pest populations. Although spiders constitute one of the most important groups of native predators in several crops, their trophic ecology remains largely unknown, especially for several generalist taxa. In laboratory, we assessed the predatory behaviour of a wandering spider (the wolf spider Lycosa thorelli (Keyserling, 1877) against several arthropods varying in size and trophic positions, all found in South American soybean and rice crops. As prey we used the bug Piezodorus guildinii (Westwood, 1837) as well as larvae and adults of the moth Spodoptera frugiperda (Smith, 1797), both being considered important pests in Uruguayan crops. We also used several non‐pest arthropods as prey, sarcophagid flies, carabid beetles and wolf spiders. All prey were attacked in more or less high, although not statistically differing, proportions. However, carabids were not consumed, and bugs were consumed in significantly lower proportions than flies. A negative correlation was found between prey size and acceptance rate. Immobilization times were longer against larvae when compared to moths and flies, while predatory sequences were longer for bugs when compared to flies, moths and spiders. In addition, we found a positive effect of prey size on predatory sequence length and complexity. Our results confirm the ability of spiders to attack and feed upon prey with different morphologies, included well‐defended arthropods, and their potential use as natural enemies of several pests in South American crops.

中文翻译：

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蜘蛛捕食者的营养生态实验评估：对乌拉圭作物生物防治的影响

保守的生物防治促进使用天然天敌来限制害虫种群的规模和增长。虽然蜘蛛是几种作物中最重要的本地捕食者群体之一，但它们的营养生态在很大程度上仍然未知，特别是对于一些通才类群。在实验室中，我们评估了流浪蜘蛛（狼蛛 Lycosa thorelli (Keyserling, 1877) 对几种不同大小和营养位置的节肢动物的捕食行为，这些节肢动物都在南美大豆和水稻作物中发现。我们使用臭虫 Piezodorus 作为猎物guildinii (Westwood, 1837) 以及草地贪夜蛾 (Spodoptera frugiperda) 的幼虫和成虫 (Smith, 1797)，两者都被认为是乌拉圭作物中的重要害虫。我们还使用了几种非害虫节肢动物作为猎物、石螟蝇、甲虫和狼甲虫蜘蛛。尽管没有统计学差异，但所有猎物都或多或少地受到攻击。然而，carabids 没有被消耗，并且昆虫被消耗的比例明显低于苍蝇。发现猎物大小和接受率之间呈负相关。与飞蛾和苍蝇相比，幼虫的固定时间更长，而与苍蝇、飞蛾和蜘蛛相比，昆虫的捕食序列更长。此外，我们发现猎物大小对捕食序列长度和复杂性有积极影响。我们的结果证实了蜘蛛攻击和捕食不同形态猎物的能力，包括防御良好的节肢动物，以及它们作为南美作物中几种害虫的天敌的潜在用途。然而，carabids 没有被消耗，并且昆虫被消耗的比例明显低于苍蝇。发现猎物大小和接受率之间呈负相关。与飞蛾和苍蝇相比，幼虫的固定时间更长，而与苍蝇、飞蛾和蜘蛛相比，昆虫的捕食序列更长。此外，我们发现猎物大小对捕食序列长度和复杂性有积极影响。我们的结果证实了蜘蛛攻击和捕食不同形态猎物的能力，包括防御良好的节肢动物，以及它们作为南美作物中几种害虫的天敌的潜在用途。然而，carabids 没有被消耗，并且昆虫被消耗的比例明显低于苍蝇。发现猎物大小和接受率之间呈负相关。与飞蛾和苍蝇相比，幼虫的固定时间更长，而与苍蝇、飞蛾和蜘蛛相比，昆虫的捕食序列更长。此外，我们发现猎物大小对捕食序列长度和复杂性有积极影响。我们的结果证实了蜘蛛攻击和捕食不同形态猎物的能力，包括防御良好的节肢动物，以及它们作为南美作物中几种害虫的天敌的潜在用途。与飞蛾和苍蝇相比，幼虫的固定时间更长，而与苍蝇、飞蛾和蜘蛛相比，昆虫的捕食序列更长。此外，我们发现猎物大小对掠食性序列长度和复杂性有积极影响。我们的结果证实了蜘蛛攻击和捕食不同形态猎物的能力，包括防御良好的节肢动物，以及它们作为南美作物中几种害虫的天敌的潜在用途。与飞蛾和苍蝇相比，幼虫的固定时间更长，而与苍蝇、飞蛾和蜘蛛相比，昆虫的捕食序列更长。此外，我们发现猎物大小对捕食序列长度和复杂性有积极影响。我们的结果证实了蜘蛛攻击和捕食不同形态猎物的能力，包括防御良好的节肢动物，以及它们作为南美作物中几种害虫的天敌的潜在用途。