Strawberry mite

Phytonemus pallidus fragariae

Profile

Strawberry mites are microscopic mites that mainly infest the heart leaves of strawberry plants in the open field and greenhouse, but also ornamental plants such as cyclamen.

Appearance

The whitish-yellow soft-skin mites are barely visible to the naked eye and are 0.2-0.3 mm long. In females, the last of the four pairs of legs is thread-like, in males pincer-like.

An exact species determination based on morphological characteristics, which can only be performed with the microscope, is difficult and currently under discussion.

Biology

The adult females overwinter well hidden in the folded leaves or at the base of the petioles. They leave the winter quarters in April, seek out the inner leaves and lay eggs there in large numbers. After only a few days, the six-legged larvae hatch, and in ten to 14 days they develop into adult mites. Five to seven generations emerge per year, which overlap.

Damage symptoms

Damage picture of strawberries

Plants infested with strawberry mites grow compressed. The heart leaves curl strongly, turn brown and dry up. The runner formation and yield are greatly reduced.

Damage to cyclamen

In cyclamen, curling and hardening of the young leaf margins and deformation of the petioles occur. Flowers remain compressed and open with difficulty, are deformed and discolored, or dry up and fall off.

Host plants

Strawberry mite occurs on strawberry, cyclamen, usambara violet(Saintpaulia), begonia, chrysanthemum, fuchsia and geranium.

Distribution

The strawberry mite occurs worldwide on its host plants.

Propagation and transmission

The spread of the pest is promoted by infested planting material, and in the case of strawberries also by too frequent cultivation at the same location.

Economic importance

Strawberry mite occurs on strawberry in nests beginning in April and can cause severe yield loss, up to and including plant uprooting, under conditions of high relative humidity and high temperatures.

Prevention and control

Specialized information

Publications

Blümel, S., Holzer, U., 1992. pests and diseases in strawberry crops. Better Fruit, 37(5), 25-29.

Last updated: 25.09.2023

automatically translated