Using portable eDNA technologies for Australian Biosecurity: Khapra Beetle Case Study

Khapra beetle, Trogoderma granarium Everts, 1898, is a serious pest of stored grain products globally. This study tested laboratory and portable molecular technologies to detect khapra beetle environmental DNA extracted from dust samples collected during biosecurity responses to khapra beetle incursions in Australia. 

Airborne and floor dust samples were collected using handheld vacuum cleaners and eDNA was extracted using either field or laboratory-based extraction methods and then analysed using laboratory benchtop real time PCR machines and portable machines with two TaqMan and one LAMP-based assay. 

We showed that can successfully collect, extract, and amplify khapra beetle eDNA from dust samples by qPCR, but this was not successful using LAMP.  The portable technologies tested in this study (Franklin™ Real Time Thermocycler and Genie III) accurately amplified all tissue derived DNA during assay optimisation and field testing, highlighting the capacity of these technologies to complement biosecurity in confirming specimen ID. We have now been able to refine methods to minimize sample cross-contamination and have demonstrated the potential of portable molecular technologies as tools for biosecurity applications.  This study also showed that eDNA-based molecular detection methods can complement global trade biosecurity for one of the most invasive and important grain pests worldwide.