Pest profile

Tuliptree Aphid

Illinoia liriodendri · Hemiptera: Aphididae[3]

Tuliptree aphids cluster under tulip tree leaves at the branch tips and produce copious honeydew that coats the plants and surfaces below.[1]

Pale yellow-green tuliptree aphid with long legs, with smaller nymphs on a leaf
Pale yellow-green tuliptree aphid with long legs, with smaller nymphs on a leaf. Photo: Adam Kranz, public domain (CC0), via iNaturalist

How to identify it

  • They're about 0.1 inch long, green to pinkish, elongate and soft-bodied, with long legs.[1]
  • Clusters of mixed sizes sit under the leaves, especially at branch tips, and shoot tips turn dull.[1]

Where it lives

The PNW Insect Management Handbook covers it on tulip trees in Pacific Northwest landscapes.[1]

US map: public records from 20 states since 1990 (GBIF).

Biology and life cycle

Adults lay eggs in fall in crevices between buds and branches, where the eggs spend the winter.[1]

Eggs hatch at budbreak, and unmated females give birth to live young; winged adults that can move to new hosts develop in fall.[1]

Damage and signs

  • Copious honeydew coats the plants below, grows black sooty mold and is a sticky nuisance on decks and cars.[1][2]

Health risk

It feeds on plants; the PNW Insect Management Handbook mentions no risk to people.[1]

Control

Prevention

Start checking for aphids and their natural enemies at budbreak in spring.[1]

Avoid heavy nitrogen fertilizer and heavy watering, which produce the succulent growth aphids favor.[2]

Traps and physical control

Wash aphids off with a strong stream of water where you can reach them.[2]

Biological control

Lady beetles, syrphid fly larvae, green lacewings and parasitoid wasps attack aphids; avoid broad-spectrum sprays that kill them.[2]

Common questions

Why is my car sticky under the tulip tree?
Tuliptree aphids produce copious honeydew that falls on whatever is below.[1][2]
When do tuliptree aphids start?
Overwintering eggs hatch at budbreak in spring, so start checking then.[1]

Sources

  1. Pacific Northwest Pest Management Handbooks (OSU, WSU, University of Idaho), “Tuliptree (Liriodendron): Tuliptree aphid (Insect Management Handbook).” pnwhandbooks.org/insect/hort/landscape/hosts-pests-landscape-plants/tuliptree-liriodendron-tuliptree-aphid (accessed 2026-10-06)
  2. Pacific Northwest Pest Management Handbooks (OSU, WSU, University of Idaho), “Landscape pests: Aphid (Insect Management Handbook).” pnwhandbooks.org/insect/hort/landscape/common/landscape-aphid (accessed 2026-10-06)
  3. iNaturalist, “Illinoia liriodendri taxon page (order and family).” www.inaturalist.org/taxa/244604 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.