Description of the Pest
The bermudagrass mite is an eriophyid mite that is so small it can barely be seen even with a 10X hand lens. It has a wormlike shape with all four legs and mouthparts at the anterior end. Eggs are spherical, transparent, and about one-third the length of the adult mite. They are laid under leaf sheaths. One generation (from egg through two nymphal stages and reaching the egg-laying adult stage again) takes 7 to 10 days in summer when temperatures are in the 80° to 110°F range.
Susceptible Species
Common bermudagrass. Hybrid bermudagrass is resistant.
Damage
Adult and immature mites suck juices and inject toxic saliva that shortens internodes and swells leaf sheaths, forming a witches'-broom growth pattern. Damage first appears in spring and is followed by dieback and browning in summer.
Management
If bermudagrass mite is infesting turfgrass, reducing nitrogen fertilization and close mowing or scalping with removal of clippings can slow down reproduction of, or physically remove, bermudagrass mites. To confirm presence of this mite, examine leaf sheaths of stunted plants with a 10X or 30X hand lens for mites and their eggs. Damage thresholds have not been established for this pest, but if a treatment seems necessary, mow the turf closely and remove clippings first. In addition to physically removing most of the population, it may also displace remaining mites so that they are more readily contacted by the miticide. After mowing, irrigate the turf and spray while the grass is still wet. To increase the chance of getting the pesticide under the leaf sheath, add adequate spreader-sticker to the spray mixture. Do not water or cut the grass within 24 hours of chemical treatment. A second application 10 days after the first may be necessary to obtain satisfactory control.
| Common name | Amount per 1000 sq ft** | Ag Use REI‡ |
NonAg Use REI‡ |
|
|---|---|---|---|---|
| (Example trade name) | (hours) | (hours) | ||
| Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Always read the label of the product being used. | ||||
| A. | BIFENTHRIN | |||
| (Talstar) | Label rates | — | Until dry | |
| MODE-OF-ACTION GROUP NUMBER1: 3A | ||||
| COMMENTS: Not for use on sod farms or in commercial seed production. May cause water quality issues. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | ||||
| B. | DELTAMETHRIN | |||
| (DeltaGard G) | 2–3 lb | — | — | |
| MODE-OF-ACTION GROUP NUMBER1: 3A | ||||
| COMMENTS: To control adults. Not for use on sod farms or in commercial seed production. For best results, irrigate with an adequate quantity of water to thoroughly moisten grass and thatch and to dissolve the granules. | ||||
| ** | Apply sprays in 25 gal water/1000 sq ft | |||
| 1 | Rotate chemicals with a different mode-of-action group number, and do not use products with the same mode-of-action group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a group number of 1B; chemicals with a 1B group number should be alternated with chemicals that have a group number other than 1B. Mode-of-action group numbers ("un"=unknown or uncertain mode of action) are assigned by IRAC (Insecticide Resistance Action Committee). | |||
| ‡ | Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Agricultural use applies to sod farms and commercial seed production. | |||
| — | Indicates use is not listed on label. | |||