Data from: Molecular detection of trophic links in a complex insect host-parasitoid food web

Previously, host-parasitoid links have been unveiled almost exclusively by time-intensive rearing, while molecular methods were used only in simple agricultural host-parasitoid systems in the form of species specific primers. Here we present a general method for molecular detection of these links applied to a complex caterpillar-parasitoid food web from tropical rainforest of Papua New Guinea.
We DNA barcoded hosts, parasitoids and their tissue remnants and matched the sequences to our extensive library of local species. We were thus able to match 87% of host sequences and 36% of parasitoid sequences to species, and infer subfamily or family in almost all cases.
Our analysis affirmed 93 hitherto unknown trophic links between 37 host species from a wide range of Lepidoptera families and 46 parasitoid species from Hymenoptera and Diptera by identifying DNA sequences for both the host and the parasitoid involved in the interaction.
Molecular detection proved especially useful in cases where distinguishing host species in caterpillar stage was difficult morphologically, or when the caterpillar died during rearing.
We have even detected a case of extreme parasitoid specialization in a pair of Choreutis species which do not differ in caterpillar morphology and ecology.
Using the molecular approach outlined here leads to better understanding of parasitoid host specificity, opens new possibilities for rapid surveys of food web structure and allows inference of species associations not already anticipated.

此前，寄主-拟寄生者（host-parasitoid）间的营养联系几乎完全通过耗时耗力的饲养实验得以揭示，而分子方法此前仅以物种特异性引物的形式，应用于简单的农业寄主-拟寄生者系统中。
本研究提出了一种通用的分子检测方法，用于揭示这类联系，并将其应用于巴布亚新几内亚热带雨林中一个复杂的鳞翅目幼虫-拟寄生者食物网。
我们对寄主、拟寄生者及其组织残体开展了DNA条形码（DNA barcode）分析，并将所得序列与我们构建的大型本地物种序列库进行比对。最终，我们成功将87%的寄主序列与36%的拟寄生者序列匹配至具体物种，且几乎所有样本均可推断其所属亚科或科。
通过比对交互双方——寄主与拟寄生者的DNA序列，我们的分析确认了93个此前未被报道的营养联系，涉及37种隶属于多个鳞翅目（Lepidoptera）科的寄主物种，以及46种隶属于膜翅目（Hymenoptera）与双翅目（Diptera）的拟寄生者物种。
分子检测方法在两类场景中尤为实用：一是鳞翅目幼虫阶段的寄主物种难以通过形态学区分，二是饲养过程中幼虫死亡的情况。
我们甚至在一对幼虫形态与生态学特征并无差异的宽卷蛾属（Choreutis）物种中，发现了一例极端的拟寄生者寄主特化案例。
采用本文所述的分子检测方法，能够增进我们对拟寄生者寄主专一性的认知，为食物网结构的快速调查提供全新可能，同时还可推断出此前未被预想的物种间互作联系。