From paddock to the lab: send in your bluegreen aphid samples this Autumn
Growers and agronomists across Australia are being called on to send in samples of bluegreen aphids after research has confirmed further spread of insecticide-resistant populations.
The bluegreen aphid (Acyrthosiphon kondoi) is commonly found in lucerne, clover and other legume crops. A tiny, but harmful pest, it feeds directly on foliage, damages the plant and can spread harmful viruses that devastate crops.
AgriFutures Australia, with support from Lucerne Australia, is continuing to invest in important research that will help growers and the wider industry to understand and manage bluegreen aphids. The project was launched in September 2022 in response to industry concerns about resistance of the pest to commonly used insecticides.
The project team from Cesar Australia have been busy collecting bluegreen aphid populations from across southern Australia, looking at where they have spread, what crop they are in and determining levels of resistance to chemicals.
The team has now collected and established 16 bluegreen aphid populations in the lab, with samples originating from SA, NSW, VIC and WA. Tests on these samples have revealed seven new populations of bluegreen aphids have developed insecticide resistance to organophosphates and carbamates, importantly three of these populations were obtained from paddocks with no reported history of chemical control failures. The team detected resistance in VIC for the first time and findings also suggest resistance has spread into new regions of south-eastern Australia and much further west in SA (to the Eyre Peninsula) than previously reported.
Managing bluegreen aphids
As part of this project Cesar Australia is developing long-term pest management guidelines, including the testing of new chemical control options. So far, Cesar Australia has identified flupyradifurone as a potential alternative chemical control option for management of bluegreen aphids in Australia, however more work needs to be done before this is confirmed.
Evatt Chirgwin, Project Lead, Cesar Australia explained that flupyradifurone has not been approved for use in Australia yet.
“Flupyradifurone is used to control bluegreen aphids in other countries and may provide an option for control here in the future.”
“Our early work suggests flupyradifurone may be effective against Australian bluegreen aphids that have developed resistance to other insecticides (e.g., organophosphates and carbamates). However, we need to consider the production costs, registration viability and the impact of the chemical on other insects that benefit the crop before it is introduced as a chemical option to growers,” Evatt said.
“In the meantime, where chemical control is needed, we encourage growers and agronomists to rotate between chemicals with different modes of action to slow the growth of insecticide resistance and send in bluegreen aphid samples for screening to Cesar Australia.”
“Natural enemies can also help control aphids. Predatory insects, including ladybirds, parasitoid wasps, hoverflies, and lacewings naturally occur in paddocks, and can all help keep bluegreen aphid numbers in check.”
Send in your sample for free testing
Autumn and spring are peak times for bluegreen aphid outbreaks with Cesar Australia now calling on pasture seed growers and agronomists to send in samples of the pest for screening to further map the spread of resistant populations.
The team is particularly interested in bluegreen aphids from white clover crops in SA and TAS and from lucerne crops from VIC and NSW.
“The more samples we receive the better we can map the spread of the resistant populations which will allow us to provide more regional and crop-specific recommendations to growers,” Evatt explained.
To help identify bluegreen aphids, growers can obtain ID guidelines on Cesar’s pest fact webpage or use the GRDC crop aphids back pocket guide.
To send in samples, growers need to use a non-crushable plastic container (e.g. a lunch box), include at least 50 non-disturbed leaf samples on a piece of paper towel and use an overnight express post bag.
To guarantee samples are processed in a timely manner, growers are encouraged to send samples by overnight express post on Mondays through to Wednesdays, only. Growers should avoid sending samples towards the end of the week or over the weekend.
Samples should be addressed to:
Bluegreen aphid resistance testing service
Level 1, 95 Albert St
Brunswick VIC 3056
Once samples have been posted, growers are asked to notify Cesar Australia via email at firstname.lastname@example.org .
Growers can be reimbursed for the cost of postage by emailing their tax invoice to Cesar Australia.
To read more about sending in your bluegreen aphid samples, visit: https://cesaraustralia.com/resources/sending-aphids-for-resistance-testing/