How to Manage Pests

UC Pest Management Guidelines


Stink Bugs

Scientific Names:
Consperse stink bug: Euschistus conspersus
Say stink bug: Chlorochroa sayi
Western brown stink bug: Euschistus impictiventris

(Reviewed 5/13, updated 5/13)

In this Guideline:


The stink bug adult is shield-shaped with the posterior angles of the pronotum extended to prominent points. They are about 0.5 inch long, and more than half as wide. Color varies from green to dark brown. Nymphs may be nearly round and black or various colors in early instars. Eggs are barrel-shaped and laid in groups, usually in multiples of seven.


Stink bugs puncture squares and bolls and cause young cotton bolls to drop; however, principal damage is to older bolls. On older bolls lint may be stained and matted, and seeds shrunken by stink bug feeding. Injured locks or bolls may fail to open. Stink bugs may also introduce bacteria and fungi that cause boll rots.


While it is seldom worthwhile to monitor for stink bugs, you should be alert for them during crop emergence and seedling growth, especially along the edge of the field closest to crop or weed hosts such as alfalfa grown for seed, grain sorghum, or Russian thistle. Also, look for stink bugs when sampling for lygus bugs with a sweep net. The sweep net is not an efficient way to sample stink bugs, however, because they feed on bolls on the bottom portion of the plant.

In early September, search plants by looking for the brown stains of fecal spots beneath the bracts of bolls to detect the presence of the bugs (they are under the bracts of green bolls). Treat if you can find more than 20 to 25 adult bugs by searching six or seven randomly chosen plants. This threshold applies only until early September because after that time, the bugs will not be feeding on bolls.

Common name Amount per acre** R.E.I.‡ P.H.I.‡
(example trade name)   (hours) (days)

  Calculate impact of pesticide on air quality
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, also consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Not all registered pesticides are listed. Always read the label of the product being used.
  (Orthene 97) 0.7 lb 24 21
  PERSISTENCE: Pest: Moderate NE:2 Moderate
  COMMENTS: An organophosphate. Do not graze or feed trash to livestock. Apply in water at 5–10 gal spray/acre by air or 10–25 gal spray/acre by ground. May induce outbreaks of spider mites.
  (Mustang Max) 2.64–3.6 oz 12 14
  PERSISTENCE: Pest: Long NE:2 Moderate
** Mix with sufficient water to provide complete coverage.
Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of 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). For additional information, see their Web site at
2 NE = natural enemies



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Cotton
UC ANR Publication 3444

Insects and Mites

  • L. D. Godfrey, Entomology, UC Davis
  • P. B. Goodell, UC IPM Program and Kearney Agricultural Research and Extension Center, Parlier
  • E. T. Natwick, UC Cooperative Extension - Desert Research and Extension Center, Imperial County
  • D.R. Haviland, UC Cooperative Extension, Kern County and UC IPM Program
  • V. M. Barlow, UC Cooperative Extension, Riverside County and UC IPM Program
Acknowledgment for contributions to Insects and Mites:
  • E. E. Grafton-Cardwell, Kearney Agricultural Research and Extension Center, Parlier
  • N. C. Toscano, Entomology, UC Riverside

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