Integrated Pest Management
Bank's Grass Mite
Oligonychus pratensis
Banks grass mite (F. C. Schweissing, Bugwood.org)
Banks grass mites (Whitney Cranshaw, Colorado State University, Bugwood.org)
Banks grass mite damage (Samuel Abbott, Utah State University)
Pest Description
- very tiny arachnids, less than 1/16 inch long, requiring a 10X lens to see the identifying features
- yellow to greenish tint with patchy black spots that cover the sides of the abdomen
- colonies often associated with webbing
Host Plants, Diet & Damage
- specialist of grasses, including turfgrasses and corn
- mite feeding removes chlorophyll from cells leading to stippling (yellowish-brown spots on turf), silver discoloration and eventual turf desiccation
- webbing produced by mites may also be evident
Biology, Life Cycle & Damaging Life Stage
- overwinter in soil, leaf litter and weeds as adults
- adults are active from late spring throughout the summer
- cream-colored, spherical eggs are laid in clusters on stems and leaves
- spider mites can have multiple, overlapping generations
- nymphs and adults are damaging
IPM Recommendations
- Reduce drought-stressed plants with proper irrigation, since drought conditions favor spider mites.
- Manage grassy weed hosts.
- Avoid broad-spectrum pesticides that suppress beneficial mite predators.
- Management with pesticides can be difficult.
- Apply a pyrethroid (bifenthrin; lambda-cyhalothrin) to suppress banks grass mites.