Host specificity testing, release and successful establishment of the broom gall mite (Aceria genistae) in Australia and New Zealand for the biological control of broom (Cystius scoparius)

A form of the eriophyid mite, Aceria genistae (Nalepa) was tested between 1999 and 2001 against 34 test plant taxa and cultivars from 12 tribes for its specificity towards the invasive shrub Scotch broom, Cytisus scoparius (L.) Link, and was shown to be highly specific. The mite was approved for release in Australia and New Zealand where redistribution and monitoring programs have been put in place. After three years, 106 releases of the mite have been conducted in Australia with a 32% establishment rate. In New Zealand, 40 releases have been made with 50% establishment. Both countries are continuing releasing this mite and are monitoring its establishment.