Update on green peach aphid insecticide resistance findings and management

Both DNA testing and insecticide bioassays conducted by cesar on populations of green peach aphid (GPA) from all over Australia have revealed varying levels of resistance to the following three chemical groups: organophosphates (dimethoate, omethoate and chlorpyrifos), synthetic pyrethroids (bifenthrin and alpha-cypermethrin) and carbamates (pirimicarb). There is emerging evidence that neonicotinoids may be the next group of chemicals to have some resistance by GPA.

Resistance management

Resistance to these chemical groups is regionally specific across Australia. For this reason, having a regionally relevant resistance management strategy for GPA is a vital aspect of ensuring ongoing crop protection options. Such a strategy has been developed by the grains National Insecticide Resistance Management (NIRM) working group, which is chaired by cesar’s director, Dr Paul Umina. This document has been endorsed by Crop Life Australia and is downloadable from:



Identification of green peach aphids

Correct identification of aphid species is the first step when deciding what control option to use, because some chemicals will differ in their efficacy between aphid species. cesar and GRDC have released a Back Pocket Guide containing descriptions of 11 key crop aphid species found in Australian broadacre systems. Keep the guide on your phone or tablet by downloading it from http://www.grdc.com.au/CropAphidsBackPocketGuide.

cesar also offers an insect identification service, so you can leave out the guess work.


For further information, about aphids and insecticide resistance contact:

Dr Siobhan de Little

Senior Consultant, cesar

Ph: 03 9349 4723

Email: sdelittle@cesaraustralia.com