Data from: A molecular diagnostic tool for the preliminary assessment of host-parasitoid associations in biological control programmes for a new invasive pest

Evaluation of host-parasitoid associations can be tenuous using conventional methods. Molecular techniques are well-placed to identify trophic links and resolve host-parasitoid associations. Establishment of the highly invasive Brown Marmorated Stink Bug, Halyomorpha halys (Hemiptera: Pentatomidae) outside Asia has prompted interest in the use of egg parasitoids (Hymenoptera: Scelionidae) as biological control agents. However, little is known regarding their host ranges. To address this, a DNA barcoding approach was taken wherein general PCR primers for Scelionidae and Pentatomidae were developed to amplify and sequence >500-bp products within the DNA barcoding region of the Cytochrome Oxidase I (COI) gene that would permit identification of key players in this association. Amplification of DNA from Pentatomidae and Scelionidae was consistent across a broad range of taxa within these families, and permitted detection of Scelionidae eggs within H. halys 1h following oviposition. In laboratory assays, amplification and sequencing of DNA from empty, parasitized eggs was successful for both host (100% success) and parasitoid (50% success). When applied to field-collected, empty egg masses the primers permitted host identification in 50 – 100% of the eggs analyzed, and yielded species-level identifications. Parasitoid identification success ranged from 33 – 67% among field-collected eggs, with genus-level identification for most specimens. The inability to obtain species-level identities for these individuals is due to the lack of coverage of this taxonomic group in public DNA sequence databases; this situation is likely to improve as more species are sequenced and recorded in these databases. These primers were able to detect and identify both pentatomid host and scelionid parasitoid in a hyperparasitized egg mass, thereby clarifying trophic links otherwise unresolved by conventional methodology.利用传统方法开展寄主-寄生蜂互作（host-parasitoid associations）的评估往往可信度有限。分子技术可有效识别营养联系（trophic links），并厘清寄主-寄生蜂互作关系。入侵性极强的茶翅蝽（Halyomorpha halys，半翅目：蝽科）在亚洲以外地区的定殖，引发了学界对利用卵寄生蜂（egg parasitoids，膜翅目：缘腹细蜂科（Scelionidae））作为生防天敌（biological control agents）的研究兴趣，但目前学界对这类卵寄生蜂的寄主范围仍知之甚少。 为解决这一问题，本研究采用DNA条形码（DNA barcoding）技术手段：针对缘腹细蜂科（Scelionidae）与蝽科（Pentatomidae）设计通用PCR引物（PCR primers），扩增并测序细胞色素氧化酶I（COI）基因的DNA条形码区域内长度大于500碱基对的扩增产物，以此实现该互作体系中关键类群的物种鉴定。 针对蝽科与缘腹细蜂科类群的DNA扩增在这两个科的广泛类群中均表现稳定，且可在茶翅蝽产卵后1小时内检测出其体内的缘腹细蜂科卵。室内生物测定（laboratory assays）结果显示，对空壳被寄生卵的DNA进行扩增与测序时，寄主样本的扩增成功率达100%，寄生蜂样本的成功率则为50%。 将该引物应用于野外采集的空卵块时，可在50%~100%的检测卵中实现寄主鉴定，且可获得物种级鉴定（species-level identifications）结果。野外采集卵样的寄生蜂鉴定成功率介于33%~67%之间，多数样本可获得属级鉴定（genus-level identification）结果。此类样本无法获得物种级鉴定结果的原因在于，公共DNA序列数据库（public DNA sequence databases）中缺乏该类群的序列数据；随着更多物种被测序并上传至这类数据库，这一现状有望得到改善。 该引物可在重寄生卵块（hyperparasitized egg mass）中同时检测并鉴定出蝽科寄主与缘腹细蜂科寄生蜂，从而厘清传统方法无法解析的营养联系。