No longer a west-side story – pesticide resistance discovered in the eastern range of a major Australian crop pest, Halotydeus destructor (Acari: Penthaleidae)

Abstract

The redlegged earth mite, Halotydeus destructor (Tucker) (Acari: Penthaleidae), is an important pest of pastures, broad-acre crops, and vegetables across southern Australia. Populations of H. destructor in Western Australia have been known to be resistant to pyrethroid and organophosphorus pesticides since 2006 and 2014, respectively. Resistant populations are currently widespread across Western Australia’s southern growing region but have, until now, remained undetected in the large south-eastern Australian range of H. destructor, despite ongoing resistance screening since 2006. Following reports of a field control failure in the Upper South East district in South Australia in 2016, resistance testing determined this South Australian population was resistant to pyrethroid and organophosphorus pesticides. The levels of resistance discovered were similar to resistant H. destructor populations in Western Australia, which are associated with chemical control failures. This work confirms for the first-time that pesticide resistant populations of H. destructor are no longer isolated to Western Australia.