The invention relates to a method of controlling aphids that are resistant to neonicotinoid insecticides, using the compound pyrifluquinazon in free form or in agrochemically acceptable salt form as well as the use of compositions comprising said compound to control neonicontinoid resistant insects. In particular the methods relate to controlling neonicotinoid resistant insects in the Aphididae family, that are resistant to one or more neonicotinoid insecticides. Methods of the invention find particular use in controlling neonicotinoid resistant insects in crops of useful plants. Furthermore, the invention extends to methods of controlling plant viruses spread by neonicotinoid resistant insects.
