Natural enemies of the pest potato leafminer fly in Indonesia

Page last updated: Friday, 3 July 2020 - 3:01pm

Please note: This content may be out of date and is currently under review.

Potato leafminer fly is a potato pest in Indonesia but does not occur in Western Australia. Natural enemies help control it.

The Department of Agriculture and Food, Western Australia has worked with the Indonesian potato industry to increase the productivity of Indonesian crops planted with WA seed potatoes.

Improved productivity requires accurate identification of pests in potatoes as well as in the cabbage rotation crop.

As well as helping Indonesian farmers this information will assist Western Australian seed potato exporters understand the challenges their Indonesian customers face.

Identification

Potato leafminer fly’s Indonesian name is "lalat pengorok daun" and its scientific name is Liriomyza huidobrensis.

This fly is a major pest of potatoes in Indonesia but does not occur in Western Australia. Details on its identification and management are available in an article on the website of the Department of Agriculture and Food, Western Australia (DAFWA).

Various natural enemies attack potato leafminer fly in Indonesia. By farmers knowing more about these agents, management of potato leafminer fly without total reliance on insecticides can be possible.

Potato leafminer fly adults are distinctive with a shiny black body and a yellow spot on their back
Adult potato leafminer fly
Maggots or larvae of potato leafminer fly feed within potato leaves causing wiggly mines
Mines within a potato leaf caused by potato leafminer fly

Effective management of potato leafminer fly relies on farmers helping these natural enemies build up to attack adult flies and also the maggots which is the stage that damages leaves.

Being able to identify natural enemies of potato leafminer fly will enable farmers to see how successful they have been in encouraging these helpers.

A predatory fly that attacks potato leafminer fly adults
Fly that attacks potato leafminer fly

One of these natural enemies is a predatory fly, similar in appearance and size to a house fly. This predatory fly feeds on adult potato leafminer flies and other small flying insects.

Other natural enemies are parasitic wasps that kill the maggot stage of potato leafminer fly.

This wasp is one of many species that kill potato leafminer fly maggots that feed within potato leaf mines. Photo courtesy CSIRO Australia
Wasp that can kill potato leafminer fly maggots (photo CSIRO Australia)
This is another of the many species of wasps that kills potato leafminer fly maggots that feed within potato leaf mines. Photo courtesy CSIRO Australia
Another wasp that kills potato leafminer fly maggots (photo CSIRO Australia)

At least 19 species of parasitic wasps occur in Indonesia to attack the maggot stage of potato leafminer fly that occurs within their feeding mines in potato leaves.

Assess the number of wasps in a crop by holding potato leaves infested with potato leafminer fly maggots in jars with gauze covers for three weeks. If parasites are present, adult wasps like the ones pictured here will emerge instead of adult potato leafminer fly.

The relative numbers of wasp parasites and potato leafminer flies shows how well the wasps are working to help protect the potato crop from this pest.

Contact information

Stewart Learmonth
+61 (0)8 9777 0167