Bermudagrass mites are pests that can negatively affect golf courses, usually during spring. Bermudagrass mite injury typically appears as small, irregularly shaped areas of thinning turf. Generally, the damage is found in roughs, but it can also occur on fairways and tees. Bermudagrass stems in the affected areas become stunted and can turn yellow or brown. Affected stems develop a distinct “witch’s broom” pattern of tightly compacted nodes and leaves.
Turfgrass managers have been aware of bermudagrass mites for decades, but they have observed more frequently during Course Consulting Service visits over the past few years. It is hard to know whether mites are becoming more problematic or whether turf managers have become more proficient at identifying mite damage. However, warm and dry periods – like those that occurred during the past winter – seem to encourage mite activity. Mites also seem to be more prevalent on certain bermudagrass off-types or in patches of common bermudagrass.
Recently, a veteran superintendent at a multicourse facility inquired about a few thin areas of roughs that generally occur each spring. The distinct witch’s broom symptoms indicated bermudagrass mite activity and led to the discovery of further activity on each golf course at the facility. More than likely, bermudagrass mites had been active at the facility for years but the turf damage had seldom before escalated to the point that they were noticed. Damage related to mites also can be easily misdiagnosed as that of other types of turf stress.
If mites are identified at your golf course, first determine whether the damage they are causing is acceptable. Unlike destructive pests such as mole crickets and army worms, bermudagrass mite injury rather slowly occurs. In fact, some damaged areas may recover on their own with rainfall and additional fertilization. However, if turf damage escalates beyond acceptable thresholds there are plant protectants that can suppress mites and improve turf quality. Read, “Insect Pest Management on Turfgrass,” for more information on bermudagrass mite control.
Several new bermudagrass varieties are more tolerant of stresses like shade, drought and traffic; they may also exhibit less damage from bermudagrass mites. If mite-related turf injury is persistent in certain locations on your golf course it may be advisable to reestablish those areas with an improved bermudagrass variety.
Southeast Region Agronomists:
Chris Hartwiger, director, USGA Course Consulting Service - chartwiger@usga.org
Steve Kammerer, regional director – skammerer@usga.org
Patrick M. O’Brien, agronomist – patobrien@usga.org
Todd Lowe, agronomist – tlowe@usga.org
Information on the USGA’s Course Consulting Service