Strawberry Insect Scouting

David Owens, Extension Entomologist,

Be sure to scout strawberry plants for spider mites, cyclamen mite, and tarnished plant bugs. Spider mite thresholds for fruiting strawberries vary, but a good ballpark is 10-15 mites per leaflet. Cyclamen mites are extremely small mites that feed on the growing points leaving deformed leaf tissue and severely stunted plants. If you see indicators of cyclamen mite activity, please let us know! They are occasional pests in the area and there is an effort underway to understand how widespread they may be.

Tarnished plant bug are the most damaging insect in our area at this time. Adults and nymphs feed on flowers and developing fruit. They feed on seeds causing the portion of the strawberry around those seeds to stop growing, resulting in misshapen fruit and ‘button’ berries. Adults are a little bit smaller than your small fingernail with dark brown and yellow stripes. Nymphs are quite small and green. Shake or flick flower clusters onto plastic and count adults and nymphs. There is a dynamic sampling plan here: Check a minimum of 15 flower clusters and consider a treatment if 3 or more bugs are found. Less than that, continue sampling. Pay attention to weedy field edges where they overwinter, and especially any fields that might be near alfalfa.