Now is the time to be scouting for spider mites. Even though the weather hasn’t been hot and it definitely hasn’t been dry, we still need to be on the look out. We’ve seen some infestations in locations where the spider mites had good sources of habitat (strawberries that weren’t terminated in adjacent fields) to wait out the summer until new plants were transplanted. Here’s a good close up photo of an infested leaf.
You may see some yellowing and leaves curling in the fields if there is a large population of spider mites present. They feed on the plants by sticking their piercing-sucking mouthparts into the leaves and sucking out the sap. Here is a microscope photo of a several two spotted spidermites and their eggs.
To scout for spider mites, you’ll need a hand lens. In a field smaller than 5 acres look at 50 leaflets. In a field larger than 5 acres look at 100 leaflets. When over 4% (4 per 100 or 2 per 52) of the leaflets are infested, treat with an effective miticide. For a complete list of miticides labeled in strawberries, check out pages 10 and 11 of the Southeastern Strawberry IPM Guide. Pay close attention to the directions on the labels, as most miticides require very high spray volumes to work properly.
For more production information look at the Southeastern Regional Small Fruit Consortium website.