University of Manitoba - Faculty of Agricultural & Food Sciences - Strawberry Tarnished Plant Bug
Strawberry Tarnished Plant Bug

Problem type: Insect

Name of problem: Strawberry tarnished plant bug

Plant name(s): Strawberry

Symptoms / Characteristics:
A typical symptom of tarnished plant bug feeding is the presence of large, hollow, straw brown seeds concentrated at one end of the berry. Seed injury results in misshapen fruit, known as "catfaced" strawberries. The majority of the damage occurs while the fruit is still green. Immature tarnished plant bugs (nymphs) are responsible for most of the damage. Upon hatching in the spring, they proceed to feed on strawberry flowers and developing seeds. This type of feeding often results in uneven pollination. Foliar damage may include curling of the leaves and/or the presence of tiny white speckles.

Tarnished plant bugs range in colour from pale green to greyish-brown and have a characteristic white "V" on the back. They can reach a length of 7 mm and a width of almost 3 mm. Young nymphs are light green in colour and often develop black dots on the thorax and abdomen. They are wingless at this stage. Tarnished plant bug nymphs resemble aphids but are far more active and move much faster. These insects are known to attack most fruits, vegetables and ornamental crops. In raspberries, they cause a condition known as "crumbly berry".

Control / Preventions:
There is no means of control once the misshapen fruit has formed. Therefore it is important to monitor the plants for any signs of the insect prior to flowering. Tapping blossom clusters over a white plate or tray is an effective way to confirm the presence of injurious nymphs, remembering that they resemble aphids but have more rapid movement. Remove all weeds and tall grass in and near the strawberry patch to reduce potential adult overwintering sites. Neighbouring sod should be mowed in late fall. A registered insecticide may be applied before the flowers open.