The objectives of the project were to (i) develop techniques for evaluating insecticide efficacy against solenopsis mealybug, and (ii) evaluate the efficacy of a range of insecticides that have potential to provide effective control of solenopsis mealybug in cotton and (iii) consider the place of potential insecticide options in the context of existing IPM and IRMS strategies.Nine insecticides were evaluated. Whilst all the products have registration in cotton, none currently have registration for mealybug. In addition, some of the products were provided by the companies on a commercial-in-confidence basis. Hence this summary provides an overview of the outcomes without Glasshouse bioassays have been completed and a range of insecticides for control of solenopsis mealybug successfully evaluated. The results show that there is value in pursuing a number of options that will cause minimal disruption to key natural enemy species, particularly the ladybird Cryptolaemus montrouzieri and lacewings. The addition of organosilicone adjuvents increased the efficacy of some products significantly. the products directly.

Field evaluation of the promising options now need to be undertaken to determine whether the levels of control that they can achieve is, in practice, sufficient to manage a mealybug outbreak. Importantly, this work must be conducted in the field where the contribution of natural enemies will be an important component of the outcome. Factoring in the contribution of natural enemies will be critical to developing sustainable management strategies for this pest.Techniques for maintaining mealybug colonies in the glasshouse were developed, methodology for establishing infestations on trial plants were refined and a bioassay protocol for assessing insecticide efficacy against solenopsis mealybug in controlled glasshouse conditions was successfully implemented. The experience we have gained in conducting these trials has equipped both scientists and technical staff in the DEEDI Field Crops Entomology group with the skills necessary to conduct similar evaluations in the field. The bioassay techniques are now available for the controlled screening of biopesticide or other candidate control options.Management of neonicotinoid resistance, particularly in cotton aphid, is a significant consideration in potentially introducing additional uses for this group of insecticides. Also worthy of consideration is the implication of pursuing more than one consecutive application of promising products.