Real-time PCR assay to detect brown marmorated stink bug, Halyomorpha halys (Stål), in environmental DNA.

BACKGROUND: Early detection before establishment and identification of key predators are time-honored strategies towards effective eradication or control of invasive species. The brown marmorated stink bug (BMSB), Halyomorpha halys, is a recent exotic pest of several important crops in North America and Europe. Resulting widespread applications of insecticides have countered years of careful integrated pest management and are leading to the resurgence of other agricultural pests. Environmental DNA (eDNA) has been used effectively to detect aquatic invasives. RESULTS: We developed a real-time PCR (qPCR) assay for BMSB in a conserved region of the ribosomal DNA interspacer 1 (ITS1). We validated this assay on worldwide populations of BMSB and tested its specificity and sensitivity against other US Pentatomidae species and on guano of big brown bat, Eptesicus fuscus, which we confirmed is a BMSB predator in New Jersey. We also detected BMSB DNA after rapid (and inexpensive) HotSHOT DNA extractions of soiled paper from cages briefly holding BMSB, as well as from discarded exuviae. CONCLUSION: Given the high sensitivity of our assay to BMSB environmental DNA (eDNA) in terrestrial samples, this tool should become a cost-effective approach for using eDNA to detect terrestrial invasive species and their key predators. © 2016 Society of Chemical Industry.