This research PhD study is required to intensively study molecular genetic techniques to better understand and then detect neonicotinoid resistance in cotton aphid.Since the introduction of Bt-cotton, secondary pests such as aphids, mites and bugs(examples of neonicotinoids), have become more prominent requiring targeted insecticide control. These sprays have lead to resistance in some species that have caused the chemical control to fail. Spray failures against aphids can permanently tarnish Australia’s reputation for producing high quality lint if failures lead to ‘sticky cotton’. Failures also increase grower costs and the likely hood of unforseen environmental consequences. Recently in Australian cotton there have been control failures against aphids belonging to the insecticide group known as neonicotinoids. This group includes the mainstay cotton seed treatment ‘Cruiser’ and the cost effective foliar spray ‘Shield’. It is now clear with the neonicotinoid failures that the sustainable management of aphids in Australian cotton is at risk. Research to restore neonicotinoid efficacy against aphids should be seen as an industry priority as part of an integrated program to better manage mites and mirids in Australian cotton. Bioassay with synergists will initially be used to characterise resistance as target site or detoxification to narrow a likely molecular based cause. With this knowledge the PhD study will aim to find the point mutation causing neonicotinoid resistance in cotton aphid. Knowing the causing mechanism will simultaneously elucidate the underlying cross resistance implications that are essential for effective resistance management. Once the mechanism is known its genetic sequence will be fully characterised and that will provide the first step in the development of a molecular based test for neonicotinoid resistance monitoring. Most importantly, the PhD study will train a young scientist in both bioassay and molecular genetic methodology for resistance detection. This will bridge the gap in a single scientist between the discipline of bioassay and molecular genetics that are now essential to effective resistance management. The PhD study will also further boost the human capacity available to Australian cotton to manage the ongoing problem of insecticide resistance.