Fourth International Bemisia Workshop International Whitefly Genomics Workshop
Novel Technique for the Control of Insect Growth Regulator Resistant B-Biotype Bemisia Tabaci in Australia
1 New South Wales Department of Primary Industries, Tamworth, Australia. Correspondence: robin.gunning@dpi.nsw.gov.au
2 Endura, SpA, Bologne, Italy
B-biotype Bemisia tabaci (the silverleaf whitefly), is a serious pest on cotton, grain, legume and horticultural crops in Australia. The silverleaf whitefly entered Australia resistant to most organophosphates, carbamates and pyrethroids and has since developed resistance to most other insecticides used for control, including insect growth regulators (IGRs), buprofezin and pyriproxyfen. There is cross-resistance between the two IGRs. IGR-resistance in the silverleaf whitefly is a major threat to the economic production of cotton in Australia and field control problems have occurred. IGR-resistance in Australian populations of B-biotype B. tabaci appears largely to be due to overproduced esterase isoenzymes, which apparently sequester the IGR insecticides. In this work, we investigated synergism with an esterase inhibitor, as a means to overcome IGR resistance in B-biotype B. tabaci. Esterase inhibitors such as organophosphates and piperonyl butoxide are commercially available, as they are used on cotton in Australia, in tank mixes with pyrethroids. Pyriproxyfen-resistant B-biotype B. tabaci nymphs were bioassayed with pyriproxyfen after exposure (by leaf dip) to a non-toxic dose of formulated piperonyl butoxide (PBO). Data indicated that PBO completely synergised pyriproxyfen and suppressed resistance. The use of synergists to control IGR-resistance could give effective control of B-biotype B. tabaci on cotton in Australia.