In the tropics, antagonistic seed predation networks may have different properties than mutualistic pollination and seed dispersal networks, but the former have been considerably less studied. We tested whether the structure of antagonistic tripartite networks composed of host plants, insects developing within seeds and fruits, and their insect parasitoids could be predicted from plant phylogenetic distance and plant traits. We considered subsets of the networks (‘subnetworks') at three rainforest locations (Panama, Thailand, Papua New Guinea), based on insect families, plant families or plant functional groups. We recorded 3197 interactions and observed a low percentage of realized interactions, especially in Panama, where insect host specificity was higher than in Thailand or New Guinea. Several factors may explain this, including insect faunal composition, incidence of dry fruits, high fruit production and high occurrence of Fabaceae at the Panamanian site. Host specificity was greater among seed-eaters than pulp-eaters and for insects feeding on dry fruits as opposed to insects feeding on fleshy fruits. Plant species richness within plant families did not influence insect host specificity, but site characteristics may be important in this regard. Most subnetworks were extremely specialized, such as those including Tortricidae and Bruchinae in Panama. Plant phylogenetic distance, plant basal area and plant traits (fruit length, number of seeds per fruit) had important effects on several network statistics in regressions weighted by sampling effort. A path analysis revealed a weak direct influence of plant phylogenetic distance on parasitoid richness, indicating limited support for the ‘nasty host hypothesis'. Our study emphasizes the duality between seed dispersal and seed predation networks in the tropics, as key plant species differ and host specificity tends to be low in the former and higher in the latter. This underlines the need to study both types of networks for sound practices of forest regeneration and conservation.

中文翻译：

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热带雨林中以种子和果实为食的昆虫的宿主特异性和相互作用网络

在热带地区，对抗性种子捕食网络可能具有与互惠授粉和种子传播网络不同的特性，但前者的研究却少得多。我们测试了是否可以从植物系统发育距离和植物性状预测由寄主植物、种子和果实内发育的昆虫及其寄生蜂组成的拮抗三方网络的结构。我们考虑了三个热带雨林地点（巴拿马、泰国、巴布亚新几内亚）的网络子集（“子网络”），基于昆虫科、植物科或植物功能组。我们记录了 3197 次交互并观察到实现交互的百分比很低，特别是在巴拿马，那里的昆虫宿主特异性高于泰国或新几内亚。有几个因素可以解释这一点，包括昆虫动物群组成、干果的发生率、水果产量高和巴拿马遗址豆科的高发生率。食种子者的寄主特异性高于食果肉者，以及以干果为食的昆虫，而不是以肉质果实为食的昆虫。植物科内的植物物种丰富度不会影响昆虫寄主的特异性，但在这方面，地点特征可能很重要。大多数子网络都非常专业，例如巴拿马的 Tortricidae 和 Bruchinae。植物系统发育距离、植物基面积和植物性状（果实长度、每个果实的种子数）对通过抽样工作加权的回归中的几个网络统计数据具有重要影响。路径分析揭示了植物系统发育距离对寄生蜂丰富度的直接影响较弱，表明对“讨厌的宿主假设”的支持有限。我们的研究强调了热带地区种子传播和种子捕食网络之间的二元性，因为关键植物物种不同，而且前者的寄主特异性往往较低，而后者较高。这强调需要研究两种类型的网络，以实现良好的森林再生和保护实践。