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Sycamore Plant Bug

Plagiognathus albatus[3]

The sycamore plant bug is a small plant bug that feeds on the leaves of sycamore and London planetree in spring.[1][2]

Group
Insect
Order
Hemiptera
Family
Miridae
US records
22 states
Sources
3 cited
Updated
2026-10-16
Sycamore plant bug, a small pale plant bug with dark markings
Sycamore plant bug, a small pale plant bug with dark markings. (c) Alexis Smith, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0
On this page
  1. Identification
  2. Look-alikes
  3. Where it lives
  4. Biology
  5. Damage and signs
  6. Health risk
  7. Control
  8. Related profiles
  9. Common questions
  10. Sources

How to identify it

  • Adults are about 1/4 inch long, yellowish brown with whitish wings; nymphs are smaller, wingless and yellowish brown.[1]
  • Look for the bugs on leaves as they expand in spring; feeding spots start yellow and later brown and fall out.[1][2]

Look-alikes

Look-alikeHow to tell them apart
Sycamore leaf beetleIts adults and larvae chew larger, irregular holes in sycamore leaves than this bug's feeding spots.[2]
Sycamore lace bugAnother sap feeder on sycamore leaves.[1][2]

Where it lives

Known from the northeastern United States and parts of Canada, and from Utah.[1][2]

US map: public records from 22 states since 1990 (GBIF).

Biology and life cycle

It overwinters as eggs in the bark or woody tissue near buds; eggs hatch in spring once leaves have expanded to about 1 1/2 inches.[1][2]

Nymphs feed on both leaf surfaces, adults are present until midsummer, and there is one generation a year.[1][2]

Damage and signs

  • Feeding leaves yellow spots that turn brown and may drop out, giving leaves a ragged, tattered look; young leaves may be mottled and distorted.[1][2]
  • UMass notes even small numbers, 1 to 15 per foot of branch, can cause noticeable damage, though harm to healthy trees is mostly cosmetic.[1][2]

Health risk

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

Control

Prevention

Keep trees healthy and tolerate the mostly cosmetic damage; check leaves for nymphs as they expand in spring.[1][2]

Traps and physical control

On small trees, nymphs can be washed off with a strong jet of water.[2]

Common questions

Why are my sycamore leaves full of brown spots and holes in spring?
Sycamore plant bugs feeding on young leaves are one cause.[1][2]

Sources

  1. Utah State University Extension (Integrated Pest Management), “Sycamore Plant Bug (Ornamental Pest Guide).” extension.usu.edu/planthealth/ipm/ornamental-pest-guide/arthopods/plant-lace-seed-bugs/sycamore-plant-bug.php (accessed 2026-10-16)
  2. UMass Extension Landscape, Nursery and Urban Forestry Program (Landscape Insect & Mite Guide), “Plagiognathus albatus (Sycamore Plantbug).” www.umass.edu/agriculture-food-environment/landscape/publications-resources/insect-mite-guide/plagiognathus-albatus (accessed 2026-10-16)
  3. iNaturalist, “Plagiognathus albatus taxon page (order and family).” www.inaturalist.org/taxa/495015 (accessed 2026-10-06)

Updated 2026-10-16. Built from sourced records. Spot an error? Tell us.