Agriculture: Bermudagrass Seed Production Pest Management Guidelines

Bermudagrass Mirid

  • Trigonotylus tenuis
  • Description of the Pest

    This plant bug may be abundant on bermudagrass florets and leaves. Trigonotylus tenuis is a small, light green, narrow, stilt-legged seed bug. Adults and immatures may be found in bermudagrass at any time from spring through fall.


    Trigonotylus tenuis is of greatest concern during spring and fall seed-production seasons from regrowth through bloom. Its feeding can reduce plant vigor, stunting growth and delaying the development of florets. Adult feeding on developing seeds also reduces seed yields.


    Monitor seed fields with a sweep net for Trigonotylus tenuis from regrowth through bloom. Treat if Trigonotylus tenuis counts reach 100 per sweep. When fields are developing seed, monitor for adult bugs only, as nymphal mouthparts do not appear to be large enough to attack developing seed. One adult mirid per 90° sweep 2 weeks before summer harvest can reduce uncleaned seed yields by almost 20 pounds per acre.

    Common name Amount per acre REI‡ PHI‡
    (Example trade name) (hours) (days)
    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‚Äôs properties and application timing. Always read label of product being used.
      (Orthene) 75S 1.33 lb 24 0
      COMMENTS: Available for use under a 24(c) registration. Do not feed crop residue to livestock or allow animals to graze treated areas. Do not apply this product through any type of irrigation system.
    Restricted entry interval (REI) is the number of hours from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of the two intervals is the minimum time that must elapse before harvest.
    * Permit required from county agricultural commissioner for purchase or use.
    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 are assigned by IRAC (Insecticide Resistance Action Committee).
    Text Updated: 01/07
    Treatment Table Updated: 06/09