How to identify it
- Adults are small, orange to yellow, with fringed wings; females are about 0.6 to 0.9 mm long.[1][2]
- Larvae are clear, yellow or light orange; second-stage larvae are stout, spindle-shaped and wingless.[1][2]
- Damage is scabby gray or silvery scarring on the rind, often a ring scar spreading out from under the sepals as the fruit grows.[1][2]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Western flower thrips | Common on citrus blossoms in spring but does not damage the plants or fruit; its larvae have a more elongated abdomen.[1][2] |
| Onion thrips | Also found on citrus in Arizona without injuring the plants or fruit.[1] |
Where it lives
It is native to the southwestern United States and northwestern Mexico and is the most economically damaging insect on Arizona citrus.[1]
Biology and life cycle
Most eggs are laid in fall in new growth and hatch in March with the spring flush; in spring and summer, females lay about 25 eggs in new leaves, young fruit or green twigs.[1][2]
It doesn't develop below 58°F and can have 7 to 12 generations a year in warm weather; cold, wet years reduce problems.[2][1]
Second-stage larvae do most of the damage, feeding under the sepals of young fruit.[1][2]
Damage and signs
- Fruit is most susceptible from petal fall until about 1.5 inches across; all citrus can be affected, and navel oranges are more susceptible than Valencias.[1][2]
- It also feeds on many other plants, including roses, grapes, avocados, blueberries and mango.[1]
- Leaf damage on healthy trees is tolerated; treatment is aimed at protecting young fruit.[2]
Health risk
Control
Prevention
Broad-spectrum sprays (organophosphates, carbamates, pyrethroids, foliar neonicotinoids) tend to increase thrips by killing natural enemies.[2]
Biological control
Predatory mites, spiders, lacewings, dustywings and minute pirate bugs help keep it in check when pressure is low to moderate.[1][2]
Pesticides
Spinosad is among the selective options relatively nontoxic to beneficial insects and mites; check new young fruit with a 10x lens from petal fall to decide if treatment is needed.[2][1]
Common questions
- Why do my oranges have a silvery ring around the stem end?
- A ring scar is typical citrus thrips damage from larvae feeding under the sepals of young fruit.[1][2]
- Are the thrips on my citrus blossoms a problem?
- Not necessarily; western flower thrips on blossoms don't damage citrus.[1][2]
- When are citrus fruits at risk?
- From petal fall until fruit reach about 1.5 inches across.[1]
Sources
- University of Arizona Cooperative Extension, “Identification and Management of Citrus Thrips.” extension.arizona.edu/publication/identification-and-management-citrus-thrips (accessed 2026-10-15)
- University of California Statewide IPM Program, “Citrus Thrips (Pest Management Guidelines: Citrus).” ipm.ucanr.edu/agriculture/citrus/citrus-thrips/ (accessed 2026-10-15)
- iNaturalist, “Scirtothrips citri taxon page (order and family).” www.inaturalist.org/taxa/308419 (accessed 2026-10-06)