Loop-mediated isothermal amplification (LAMP) assay for identification of Australian Plague Locust (APL),...

The Australian Plague Locust (APL), Chortoicetes terminifera, the most important pest locust in Australia, can cause significant damage to crops and grasslands when present in high numbers. We have developed a new LAMP (loop-mediated isothermal amplification) assay specifically targeting APL for rapid diagnostics to support locust management. We tested five DNA extraction methods for potential near-field use and designed an APL gBlock as a synthetic positive control. The performance of new LAMP assay was assessed against a panel of eleven closely related Australian grasshopper species (family Acrididae). The optimised LAMP assay produced amplification only from APL DNA, on average in 18.0 ± 2.9 min, with an anneal derivative of 79.9 ± 0.5 °C, and gBlock produced a different anneal derivative of 83.5 ± 0.5 °C. The LAMP assay was sensitive to very low levels of DNA, with detection down to 0.2 picogram of APL DNA. The speed of application and accurate identification results generated, enables this scalable assay to be easily used in the field as a new tool for APL control, providing positive/negative results within an hour. This capability will prove an essential aid during sporadic APL population growth events, when accurate species-level identification of substantial numbers of nymphs, prior to adult locusts swarming, is a critical aspect of pest management.