Growers, agronomists with suspected new aphid species can have Melbourne entomologist help

MORE HELP: Megoura crassicauda is a new pest in Australia that could affect some legume crops. Photo: Cesar
MORE HELP: Megoura crassicauda is a new pest in Australia that could affect some legume crops. Photo: Cesar

Growers and agronomists who suspect the presence of a recently discovered aphid species in vetches, faba beans and broad beans now have more help.

Entomologists at Cesar research organisation in Melbourne can inspect high-quality images and aphid samples to determine whether crops are infested with the new pest, Megoura crassicauda.

Cesar entomologist Julia Severi said the species was native to north-east Asia and since its initial detection in suburban Sydney in October last year, its known distribution has now expanded to Tamworth and Breeza.

The identification service is supported by the Grains Research and Development Corporation, and is being made available through the GRDC’s investment in the PestFacts south-eastern invertebrate crop pest information platform. 

Ms Severi said it was unclear where else the aphid was present or how quickly it was likely to spread into new regions.

“And while little is known about the potential economic impact, observations of its activity in Australia so far indicate that the aphid has a high reproductive capacity and could threaten faba and broad bean production,” she said.

NSW DPI is now doing more surveillance in the growing areas of northern NSW.

  • For more information about Cesar’s aphid identification service, call (03) 9349 4723 or email pestfacts@cesaraustralia.com
  • Report detections of unusual aphid species to the Exotic Plant Pest Hotline on 1800 084881

About the aphid

Ms Severi said the aphid had a very distinctive appearance.

“Adults are dark green and spindle-shaped with long antennae and black legs. They are relatively large aphids – approximately 2.5-3 millimetres in length – and have vibrant, red eyes.”

M. crassicauda can form mixed colonies with pea aphid and cowpea aphid, two species that are widespread in Australia, and infect faba beans and vetch.

While information on the lifecycle and behaviour of M. crassicauda is limited, they are known to reproduce asexually (female aphids giving birth to live nymphs without mating) and sexually (females laying eggs after mating), according to Ms Severi.

Management

In terms of management, there are no current registered insecticides for this pest. 

Dimethoate is registered to control aphids in faba beans.

Paraffinic oil is registered for use on faba beans and vetches to provide suppression of green peach aphid.

Initial work conducted by NSW DPI using pirimicarb was efficacious.

Permits for the use of pirimicarb, dimethoate, chlorpyrifos and lambda-cyhalothrin in faba beans and vetch are being sought.

The role of natural enemies in controlling M. crassicauda remained unclear, Ms Severi said.

“Undoubtedly, we will learn more about M. crassicauda in the Australian context with time, including the role of natural enemies, its potential as a virus vector, and how it will behave and spread in our climate.”