WSU Extension

Hortsense

Lawn and Turf : Chinch bugs
(revision date: 3/10/2017)


Biology
Chinch bugs feed on the stems, injecting a toxic saliva as they feed. Damage typically appears in mid- to late summer. Affected grass turns yellow and dies. The damage often resembles drought stress, but grasses damaged by chinch bugs do not recover with watering. Damage is more severe on lawns with moderate or severe drought stress, but less damage is seen in shady areas. The adults are small black bugs with white wing markings. They are about 3/16" long. The immature bugs (nymphs) are reddish with black or white markings. Perennial ryegrasses and fine and tall fescues with high levels of endophytic fungi are resistant to chinch bugs.
Management Options

Non-Chemical Management
  • Provide proper culture. Vigorous, well-irrigated lawns are not likely to be damaged by chinch bugs.
  • A fungus which parasitizes chinch bugs is also encouraged by proper watering.
  • Chinch bugs may be attracted to lawns with thatch buildup. Annual thatch removal will help control chinch bugs.
  • Many insects including big-eyed bugs are natural enemies of chinch bugs. Avoid use of broad-spectrum insecticides which kill beneficial insects.
Select non-chemical management options as your first choice!

Chemical Management

Chinch bugs are not consistent pests. While conditions suitable for damage occur each year in the PNW, the last major outbreak occurred in 1985. The most resistant turfgrasses are those that are lightly fertilized and regularly irrigated.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
    Active ingredient: azadirachtin  |  EPA reg no: 70051-6-42697
  • This list may not include all products registered for this use.
Images
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Caption: Chinch bug adult
Photo by: D. Pehling
Caption: Chinch bug nymph
Photo by: K. Grey