Two-spotted spider mite
Tetranychus urticae Koch
This mite can cause severe damage to wine grapes if populations reach high densities. Thin-leaved varieties are most susceptible. These mites overwinter in leaf litter, develop on weeds in spring and move onto the vine as ground cover dries in summer. Water-stressed vines are most at risk.
The mite’s feeding removes leaf tissue, causing yellowing and then bronzing.
The most effective method of control is to protect predatory mites. Biological control is achieved with one predatory mite per 10 two-spotted mites.
The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.