Methyl bromide fumigation for eliminating macadamia felted coccid (Eriococcus ironsidei Williams) from propagating material

Abstract

The only known food-plants of Eriococcus ironsidei Williams, an important pest of macadamia in south-eastern Queensland, are Macadamia ternifolia (integrifolia) and M. tetraphylla. It is suggested that because plantations derived from uninfested nursery trees can remain free of infestation for many years, the disinfestation of propagating material such as budwood, scion wood or nursery trees is worth while. Fumigation of seedlings of M. ternifolia with methyl bromide at 55 g/m3 for 2 h at 20 deg C and 70% RH eliminated infestations of E. ironsidei. This treatment caused no damage to uninfested seedlings of M. tetraphylla nor to uninfested budwood of 4 varieties of M. ternifolia. Considerable leaf burn was caused on heavily infested seedlings of M. ternifolia but only slight leaf burn was caused on less heavily infested ones.