The amplified carboxyl-esterase mechanism leads to organophosphate resistance in GPA.

Interpreting resistance-testing results for organophosphates is more complex. The use of pyrethroids and pirimicarb (even at high rates) will not provide control against these populations. Genotyping has revealed GPA from many field-collected populations are resistant clones, possessing resistance to organophosphates, carbamates, pyrethroids and neonicotinoids. Red dots represent resistant population location, green represent susceptible population location. Insecticide resistance maps of green peach aphid collected during 2017/2018 for pyrethroids, carbamates, organophosphates, and neonicotinoids. Insecticide resistance maps show that resistance is commonplace almost all (>90%) populations tested showed resistance to carbamates, pyrethroids, organophosphates and neonicotinoids (Figure 1).įigure 1. Results and discussion Green peach aphid resistance monitoring Toxicity data for each population was established against four insecticide classes (organophosphates, synthetic pyrethroids, carbamates, neonicotinoids). Nine field populations of oat aphid were collected from localities representing the major grain growing regions of Australia Tamworth (TMW), Picola (PIC), Dookie (DOK), Pimpinio (PIM), Back Valley (BKV), Adelaide (ADE), Manjimup (MNJ), Capel (CAP) and Katanning (KAT). New knowledge was developed regarding the risk of resistance evolution in grain aphids and based on risk profiles and considerable base-line sensitivity data was established for multiple insecticides for two species deemed to be at risk of resistance evolution in Australia the cowpea aphid and oat aphid. The risk of incursion and local evolution of the sulfoximine and neonicotinoid-resistant mutation (known as “R81T”) has been evaluated and investigated through predictive modelling and a large network of field traps, followed by genetic testing for this mutation.Īn extensive review of resistance risk in aphid species other than GPA was also completed. The assessment of resistance was based on genetic screening of alleles for MACE, kdr, super-kdr, as well as amplification of the E4 esterase gene, and finally the CYP6CY3 (P450) copy number, which confer resistance to carbamates, pyrethroids, organophosphates, and neonicotinoids.

Screening was completed using optimised phenotypic methodologies, newly developed molecular markers for GPA populations and testing over multiple known genetic resistance mechanisms. Over 400 GPA populations were screened for resistance to carbamates, organophosphates, synthetic pyrethroids, neonicotinoids and sulfoximines. This project documented the frequency and spread of insecticide resistance in GPA through a national insecticide resistance surveillance program throughout Australia. Aphid control in these crops is achieved almost exclusively with chemical insecticides, and there is growing concern about insecticide resistance evolution in multiple aphid species. In Australia, the oat aphid (Rhopalosiphum padi) causes feeding injury which can reduce cereals yield by 6%, with the damage caused by aphid-vectored viruses reducing yield of cereal crops by up to 30%. There is a need to develop resistance management strategies that minimise the risk of increased resistance evolution, focus on targeted use of pesticides and include non-chemical options. The green peach aphid (Myzus persicae, GPA) has evolved resistance to a wide range of commonly used insecticides. In Australia, the cost of aphid injury has been estimated at $200-$400 million per year.

Monitoring of aphid predators and parasitoids allows chemical-free control of insecticide resistant aphids.Īphids are major crop pests throughout the world, attacking a broad range of crops through direct feeding, and as a vector of viral diseases.

Proper identification of aphid species is necessary to assess risk of resistance and choice of insecticide to be used.

Controlling green bridges around paddock and sowing into standing stubble is recommended.Rotate available insecticide modes of action (new modes of action to be registered in coming years).The green peach aphid insecticide resistance management strategy has been updated and should be consulted by growers and advisers.Significant differences in pyrethroid sensitivity were found between populations of oat aphid.Multiple green peach aphid populations from a specific region showed a temporary sensitivity shift to sulfoximines (sulfoxaflor, Transform®) due to an unknown mechanism.A high number of green peach aphid populations are resistant to pyrethroids, carbamates, organophosphates, and neonicotinoids.Research, Development and Extension Data.Business development and commercialisation

Aphids predators