Pest profile

Tomato Russet Mite

Aculops lycopersici · Sarcoptiformes: Eriophyidae[3]

Tomato russet mites are microscopic mites that feed on tomato stems, leaves and fruit, turning them a greasy bronze or russet color from the ground up; left unchecked they can kill plants.[1][2]

Tiny yellowish tomato russet mites among the hairs of a tomato stem
Tiny yellowish tomato russet mites among the hairs of a tomato stem. Photo: 余世文, public domain (CC0), via iNaturalist

How to identify it

  • The mites are cigar- or cone-shaped and yellowish tan to pink, and need a 14x hand lens or microscope to see.[1][2]
  • The first sign is bronzing on lower leaves and stems; the mites are found on the damaged leaves and the green leaves just above them.[1][2]
  • Damaged leaves may yellow, curl, wither and drop, and fruit can show long cracks and bronzing.[1]

Where it lives

Utah State and UC IPM both cover it on tomatoes; Utah State notes it is mainly a concern in hot, dry conditions.[1][2]

Biology and life cycle

It has multiple overlapping generations a year and overwinters as adults in crop debris.[1]

Infestations usually start near the ground and progress up the plant.[2]

Damage and signs

  • Feeding removes cell contents and bronzes stems, leaves and fruit; lower leaves dry out and the plant looks unhealthy.[1][2]
  • UC IPM says damage is typically first noticed when green fruit reaches about 1 inch.[2]

Health risk

None to people or pets.[1][2]

Control

Sanitation

Remove or destroy infested plant debris promptly, clean tools after working on infested plants, and avoid planting during hot, dry periods.[1]

Where it recurs, remove alternate hosts such as nightshades and morning glory.[2]

Pesticides

Once mites are present, sulfur or abamectin is the main option; sulfur should not be applied above 90°F or near an oil application.[1][2]

Common questions

Why are my tomato stems turning bronze from the bottom up?
Tomato russet mites cause greasy bronze stems and lower leaves that progress up the plant.[1][2]
Can I see tomato russet mites?
Not with the naked eye; you need a 14x hand lens or a microscope.[2][1]
How do I control tomato russet mite?
Sulfur or abamectin once mites are present, plus prompt cleanup of infested plants.[1][2]

Sources

  1. Utah State University Extension, “Tomato Russet Mite.” extension.usu.edu/planthealth/ipm/notes_ag/veg-tomato-russet-mite.php (accessed 2026-10-15)
  2. University of California Statewide IPM Program, “Tomato Russet Mite (Pest Management Guidelines: Tomato).” ipm.ucanr.edu/agriculture/tomato/tomato-russet-mite/ (accessed 2026-10-15)
  3. iNaturalist, “Aculops lycopersici taxon page (order and family).” www.inaturalist.org/taxa/262808 (accessed 2026-10-06)

Updated 2026-10-15. Built from sourced records. Spot an error? Tell us.