Broad Mites on Strawberries

Traits

• Broad mites lay their eggs on the undersides of stems and leaves. The eggs are extremely small and elliptical, with tiny white, diamond-shaped bumps. Broad mites are less than one one-hundredths of an inch in length. They can be colorless, amber or dark green, depending on their hosts. Although females have short, thin back legs, the legs of the males are long. Broad mites become adults within approximately five days after hatching from the eggs.

Damage

• Broad mites thrive in highly humid conditions, and they often hide in the growing points of the plants, such as the buds, or in areas of overlapping leaf development. When the eggs hatch, the mites begin feeding on the strawberry plants. As they feed, the mites inject a toxic saliva into the plant. As a result, the leaves become hard and mottled and commonly turn downward.

Precautions

• When broad mites are discovered, infected strawberry plants should be destroyed. Because the mites can be spread by workers' clothing and hands, it is critical that during the maintenance of strawberry crops, the mite-infested areas be entered last to prevent transmission and further damage. All new strawberry plants must be inspected before integrating them with existing crops, and producers must be cognizant the possibility of year-to-year broad mite infestation carryover.

Control

• Miticides can destroy broad mites on strawberries. However, effective chemical control requires frequent, high-volume chemical dispersion to optimize the destruction of broad mites in all of their life stages. No foolproof chemical control has been discovered for broad mite destruction. Hot-water treatments on infected plants have also yielded success. The plants are immersed in hot water for 15 to 45 minutes to saturate the areas where the broad mites hide.