Key messages
- Green peach aphid is an important vector of Turnip yellows virus in canola crops.
- Green peach aphid has evolved a level of resistance - or reduced sensitivity - to all insecticide modes of actions registered for use on this species in grain crops in Australia.
- cesar will be offering insecticide resistance testing services to grain growers and advisers across the 2020 and 2022 growing seasons as part of a new GRDC investment aimed at improved knowledge and management of the green peach aphid.
A new research initiative is investigating the geographical distribution of insecticide resistance in green peach aphid across Australian grain growing regions.
Grain growers and advisers are encouraged to submit green peach aphid (Myzus persicae) specimens to the National Aphid Insecticide Resistance Surveillance (NAIRS) program for resistance testing.
The testing service will be offered to the grains industry throughout the 2020 and 2022 growing seasons and will help improve understanding of distributions and levels of resistance in green peach aphid populations across Australia.
Scourge of the green peach aphid
The green peach aphid is a well-known pest to Australian canola growers, in particular.
Tending to appear in crops early in the season, the green peach aphid also feeds on a variety of other broadacre crops, broadleaf pastures and horticultural crops.
However, critically for canola growers, the pest is also responsible for the transmission of Turnip yellows virus (formerly known as Beet western yellows virus) to crops in the Brassicaceae family.
Crops infected with the virus in the early seedling stage can experience seed yield losses of more than 40 per cent. Reducing transmission rates of Turnip yellows virus is therefore an important goal for the broadacre industry.
The green peach aphid demonstrates some level of resistance - or reduced sensitivity - to all five insecticide modes of action registered for use on this species in grains - this reduces the effectiveness of chemical control options for the pest.
Resistance testing undertaken in recent years has shown that many green peach aphid populations are highly resistant to synthetic pyrethroids and carbamates, moderately resistant to organophosphates and that low-level resistance is developing to neonicotinoids.
Previous research undertaken by cesar , the Western Australian Department of Primary Industries and Regional Development (DPIRD) and CSIRO also detected a reduced sensitivity to sulfoxaflor (Transform®) in multiple populations from the Esperance region of WA.
Sulfoxaflor is the only active registered for use by the grains industry that remains fully effective against green peach aphid. If resistance to sulfoxaflor was to spread to other green peach aphid populations, it would represent a substantial threat for growers' ability to control this pest effectively.
A new project underway
NAIRS is being undertaken as part of a new four-year GRDC investment, led by cesar in collaboration with CSIRO, DPIRD, ISK, BASF and Corteva.
The project will be:
- developing new resistance testing methods;
- evaluating the risk of resistance evolution to new insecticides; and
- developing improved knowledge on the dispersal patterns of green peach aphid and the Turnip yellows virus across seasons.
By the project's end in 2023, the partners hope that growers and advisers will have a better understanding of the risks of Turnip yellows virus transmission - and improved tools for managing insecticide resistance in green peach aphids.
Submit your aphids for testing
It is advised to undertake resistance testing if you are a grower or adviser and have:
- spotted green peach aphid in your crops and they are not problematic;
- have a problem controlling green peach aphid in your crops; or
- suspect insecticide resistance in green peach aphid (or other aphid species) on your property.
In these cases, growers and advisers are being encouraged to contact Dr Marielle Babineau, research scientist, entomology, at cesar regarding the resistance testing service.
The NAIRS program is part of a new GRDC investment led by cesar in collaboration with CSIRO and DPIRD. Funding for the project is provided by GRDC, Corteva, BASF and ISK.
If you are unsure whether you have green peach aphid, you can contact the PestFacts south-eastern team at cesar for free aphid identification assistance (pestfacts@cesaraustralia.com).
More information: Dr Marielle Babineau, 03 9349 4723, mbabineau@cesaraustralia.com; www.cesaraustralia.com