AUSVEG: Wasp warfare with avid aphid-eating parasites can help prevent pesticide resistance

With pesticide resistance rising in species of aphids which feed on potatoes and spread viruses, one of the best control options for growers battling these pests may be found in nature, free of charge: parasitic wasps.

Three species of parasitic wasps can target the aphid species found in potatoes, finding young aphids and injecting eggs into their body. These eggs grow and feed for two to three days before hatching, with the larval wasp then creating a cocoon and feeding on the inside of the aphid before emerging through a chewed hole in its back when mature.

AUSVEG spokesperson Shaun Lindhe:

“While it may sound grisly, this method of controlling aphid populations can deliver valuable benefits to potato growers by offering an option which doesn’t run the risk of increasing chemical resistance among aphid populations,” said

“Chemical resistance is a pressing concern for the potato industry – and this is especially true of Green peach aphid, which has several insecticide-resistant strains that are currently moving freely across growing regions.”

“While most insecticides used to control aphids will also kill these beneficial wasps, there are some spray products where the approved active will still allow them to establish a population.”

“By rotating between these multiple approved actives, growers can prevent aphids from building up resistance and allow the wasps to continue their good work.”

“Adopting integrated pest management strategies is a great way for the industry to avoid resistance rising in problem pests, and this is a key area of research and development for the Australian potato industry,” said Mr Lindhe.

A detailed article on the role of parasitic wasps in potato crops can be found in the latest edition of Potatoes Australia [PP:not yet available online when we checked] , an industry funded magazine commissioned by Horticulture Innovation Australia, which promotes industry research and development while keeping growers and stakeholders in the loop with the latest news.