Studies on integrated control of Panonychus ulmi in New Zealand apple orchards

Abstract

Attempts were made to utilise a strain of Typhlodromus pyri Scheut. resistant to azinphos-methyl in an integrated programme to control Panonychus ulmi (Koch). Initial populations of P. ulmi were high, and T. pyri was not able to regulate the numbers of this pest. Populations of T. pyri were reduced by all rates of azinphos-methyl tested but subslantial numbers survived even the highest rates. ‘Plictran’ proved to be selective in its toxicity to the mites, favouring survival of T. pyri and mortality of P. ulmi.