A Portable High-Throughput DNA Barcoding Approach for Bulk Detection of Helicoverpa armigera

The Old World Bollworm, Helicoverpa armigera (Hubner), is a highly destructive agricultural pest that recently invaded South America and Puerto Rico. Rapid detection and response is crucial to preventing its invasion into North America. However, it is very difficult to distinguish between it and H. zea (Boddie), a closely related pest that is native to the New World. Morphological species identification is only possible through dissection of adult male genitalia; larvae and adult females cannot be distinguished. Real-time PCR techniques can identify H. armigera using variation in the rRNA internal transcribed spacer regions 1 &2 (ITS1 & ITS2). However, the reliance on single genes could overlook hybridized invaders. To improve our abilities to quickly detect H. armigera DNA in pest surveillance material, we adapted the handheld, Oxford Nanopore MinION, for rapid and portable sequencing of DNA barcodes to simultaneously sequence multiple genes from bulk DNA of unknown species, which can originate from domestic trap surveys.