Leaf eating ladybirds: potato pest in Indonesia and Western Australia

Page last updated: Friday, 3 July 2020 - 12:42pm

Please note: This content may be out of date and is currently under review.

Leaf eating ladybirds are a relatively minor pest of potatoes in Indonesia and Western Australia, but should be monitored.

The Department of Primary Industries and Regional Development, Western Australia has worked with the Indonesian potato industry to increase productivity of 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

The Indonesian name for leaf eating ladybirds is “epilachna” and their scientific name is Epilachna sp.

Leaf eating ladybirds are insects that affect potato plant vigour by feeding on the leaves.

Leaf eating ladybird adults are yellow or orange rounded beetles with varying arrangements of black spots over their backs and about 6mm long
Leaf eating ladybird adults are rounded beetles with varying arrangements of black spots over their backs and about 6mm long

The first pair of wings is modified to a hard cover with the second pair of wings folded underneath this cover. The second pair of wings allows the beetles to fly.

Adult leaf eating ladybirds lay yellow eggs in groups on either side of leaves
Adult leaf eating ladybirds lay yellow eggs in groups on either side of leaves

Leaf eating ladybird larvae grow to 8mm long and are covered in branched spines
Leaf eating ladybird larvae grow to 8mm long and are covered in branched spines

Both leaf eating ladybird larvae and adults feed only on soft leaf tissue giving damaged leaves a windowed appearance
Both leaf eating ladybird larvae and adults feed only on soft leaf tissue giving damaged leaves a windowed appearance

When fully fed, leaf eating ladybird larvae form a cocoon on the leaf which has branched spines of the larval skin attached
When fully fed, leaf eating ladybird larvae form a cocoon on the leaf which has branched spines of the larval skin attached

Management

Leaf eating ladybirds feed on solonancae or plants in the same family as potatoes such as tomato, tobacco and the weed, night shade. Remove any such plants near potato crops if this is practical.

Check potato crops for leaf eating ladybird stages of leaf damage during weekly pest monitoring. These beetles are more likely to be abundant during hot weather.

Leaf eating ladybirds cause damage only when present in high numbers. They have no natural enemies.

If leaf loss from the ladybirds reaches about 25%, a contact insecticide should give control.

Acknowledgment

Funding for this work to support Indonesian potato farmers and WA seed potato exports was provided by ACIAR (Australian Centre for International Agricultural Research) and the Department of Primary Industries and Regional Development, Western Australia.

Contact information

Alison Mathews
+61 (0)8 9777 0122