Detecting host–parasitoid interactions in an invasive Lepidopteran using nested tagging DNA metabarcoding

Abstract

Determining the host-parasitoid interactions and parasitism rates for invasive species entering novel environments is an important first step in assessing potential routes for biocontrol and integrated pest management. Conventional insect rearing techniques followed by taxonomic identification are widely used to obtain such data, but this can be time-consuming and prone to biases. Here, we present a next-generation sequencing approach for use in ecological studies which allows for individual-level metadata tracking of large numbers of invertebrate samples through the use of hierarchically organised molecular identification tags. We demonstrate its utility using a sample data set examining both species identity and levels of parasitism in late larval stages of the oak processionary moth (Thaumetopoea processionea-Linn. 1758), an invasive species recently established in the United Kingdom. Overall, we find that there are two main species exploiting the late larval stages of oak processionary moth in the United Kingdom with the main parasitoid (Carcelia iliaca-Ratzeburg, 1840) parasitising 45.7% of caterpillars, while a rare secondary parasitoid (Compsilura concinnata-Meigen, 1824) was also detected in 0.4% of caterpillars. Using this approach on all life stages of the oak processionary moth may demonstrate additional parasitoid diversity. We discuss the wider potential of nested tagging DNA metabarcoding for constructing large, highly resolved species interaction networks.

Limited dispersion and quick degradation of environmental DNA in fish ponds inferred by metabarcoding

“…Extracted DNA samples were amplified with a vertebrate-specific primer pair (Riaz et al, 2011) that targets a 106-bp fragment of the mitochondrial 12S rRNA region in fish, using a two-step PCR protocol for library preparation that implements a nested tagging approach (Kitson et al, 2019). Previous eDNA metabarcoding studies of marine mesocosms and coastal ecosystems showed that this fragment has a low false-negative rate for bony fishes (Kelly, Port, Yamahara, & Crowder, 2014;Port et al, 2016).…”

Mu-DNA: a modular universal DNA extraction method adaptable for a wide range of sample types

“…A double-indexed library was prepared following a 2-step PCR based protocol (Kitson et al 2018) using primers for the vertebrate 12S mitochondrial gene region (Riaz et al 2011, Kelly et al 2014. In short, an initial PCR reaction amplified the target region using individually indexed 12S primers for each sample.…”

Introduction: Special issue on species interactions, ecological networks and community dynamics – Untangling the entangled bank using molecular techniques

“…Yet, equally importantly, we refer to the potential for handling and individual tagging (Kitson et al, 2019) of large numbers of samples, allowing the simultaneous characterization of massive numbers of ecological samples and taxa.…”

“…In particular, DNA metabarcoding based on nested tagging offers unique opportunities for constructing large, highly resolved species interaction networks (Kitson et al, 2019). Generation of data on species associations without rearing the organisms involved to morphologically identifiable stages bypasses both important biases and highly laborious stages of work (Kitson et al, 2019;Koskinen et al, 2019 lives. It is also the basis for grouping nodes into more and less similar blocks within webs, and for comparing the roles of such similar blocks among regions (e.g., "the role of blowflies in different ecosystems").…”