Two-spotted mite: potato pest in Indonesia and Western Australia

Page last updated: Friday, 5 May 2017 - 2:53pm

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Management

Two-spotted mites feed on a wide variety of crop and ornamental plants and weeds. If infestations are noticed near potato crops, remove any infested weeds.

Mites are most likley to be present in hot weather and can increase in number rapidly.

Two-spotted mites do not have wings but in windy conditions can be blown into crops. Also, because dust interferes with natural predators, crop edges are more likely to be infested. Therefore when monitoring, pay attention to crop edges.

If mottled leaves are seen during regular crop monitoring, check leaves with a 10 times magnifier to confirm whether two-spotted mites are the cause.

When monitoring for mites, also check whether their natural enemies are present. If they are present and over successive monitoring times are increasing, they may control the mite infestation. The main natural control agents of two-spotted mite include the predators stethorus beetle, six-spotted thrips and predatory mites.

Adult Stethorus beetle that feeds on mites
Adult stethorus beetle
Larval stage of Stethorus beetle also feeds on mites
Larval stage of Stethorus beetle
Predatory mites are a similar size to two-spotted mite but are arrow head shaped and uniform pale brown. They feed on all stages of two-spotted mite
A predatory mite attacking a pest mite
Six-spotted thrips nymphs and adults feed on mites. Photo courtesy Univ Cal Riverside USA
Six-spotted thrips adult. Photo courtesy University of California, Riverside

If no natural control agents are seen and more than 20% of leaves are affected by two-spotted mites, a miticide should be applied. 

Most miticides do not kill eggs, therefore a follow-up spray 7–10 days later is often required to control new hatchings.

Acknowledgment

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

Contact information

Stewart Learmonth
+61 (0)8 9777 0167

Two-spotted mite: potato pest in Indonesia and Western Australia

Author

Stewart Learmonth