Lessons learned from phosphine resistance monitoring in Australia

Abstract

Purpose of review: Heavy reliance on phosphine to disinfest stored grain over the last few decades has led to the development of resistance in key stored grain insect pests around the globe jeopardising the long-term sustainability of this key fumigant. Australia is the only country in the world with a national resistance monitoring program which has, for over two decades, diagnosed, recorded and managed resistance to phosphine. The purpose of this review is to highlight the lessons learned from the Australian experience. Recent findings: Recent findings from the national resistance monitoring in Australia include: (1) strong resistance to phosphine in the lesser grain borer, Rhyzopertha dominica (F.); the psocid, Liposcelis bostrychophila Badonnel; and the flat grain beetle, Cryptolestes ferrugineus (Stephens); (2) strong resistances in R. dominica and L. bostrychophila have now been successfully managed through development of new fumigation protocols and changes to phosphine label; (3) identified resistance in C. ferrugineus, that is the highest level recorded so far for any stored grain pest and cannot be controlled with the current recommended dosages; (4) a nationally coordinated collaborative program balancing applied and basic research along with development and extension is the key to successful management of resistance to phosphine. Directions for future research: Research towards developing fumigation strategies to manage the strong level of resistance in C. ferrugineus at a range of temperatures is a priority as is development of an appropriate molecular phosphine resistance test. © 2011 Stewart Postharvest Solutions (UK) Ltd.