PestControlBasics
Menu

Identify

Treat

Local

About

Asparagus aphid

Brachycorynella asparagi[4]

The asparagus aphid is a tiny, waxy aphid from Europe whose feeding injects a toxin that makes asparagus ferns grow short and bushy, a 'witches' broom', and weakens the next year's spears; young plantings suffer most.[1][2][3]

Group
Insect
Order
Hemiptera
Family
Aphididae
US records
3 states
Sources
4 cited
Updated
2026-10-19

No licensed photo of this species is available yet; the identification notes below describe what to look for.

On this page
  1. Identification
  2. Where it lives
  3. Biology
  4. Damage and signs
  5. Health risk
  6. Control
  7. Related profiles
  8. Common questions
  9. Sources

How to identify it

  • Aphids are about 1/16 inch long, blue-green to gray-green and often dusted with powdery wax; unlike most aphids, their cornicles are reduced to nearly invisible openings.[2][3]
  • Infested ferns have shortened internodes and a tufted, brush-like 'witches' broom' look, especially near the tips of the lower branches, with a blue-green color.[1][2]
  • Colonies are hard to spot by eye, even for experienced scouts, so look for the distorted ferns first.[2]

Where it lives

Native to Europe, it was first found in North America in 1969 and now attacks asparagus from New England to California.[3][1][2]

US map: public records from 3 states since 1990 (GBIF).

Biology and life cycle

It overwinters as eggs laid in fall on the lower ferns and asparagus residue; in spring the young feed on spears and then the ferns.[1][3]

Populations start slowly in scattered patches and then build explosively over the season, outpacing many predators.[2]

It feeds only on asparagus, including wild and ornamental asparagus.[3]

Damage and signs

  • The toxin causes the distorted growth, and the bigger loss is reduced vigor and yield the following year; heavy infestations can kill seedlings.[2][1]
  • Newly established or weak plantings, seedling beds and 2- to 3-year-old unharvested plantings are the most vulnerable.[1][2]

Health risk

It feeds only on asparagus; UMass, UC IPM and UConn mention no risk to people.[1][2][3]

Control

Sanitation

Remove dead ferns in fall or winter and till in spring to destroy overwintering eggs; this usually controls the pest.[3]

Biological control

Lady beetles, lacewings, predatory midges, flower fly larvae, parasitic wasps and fungi all attack it, though its fast reproduction can overwhelm them.[3][2]

Pesticides

Scout ferns after harvest, especially in young plantings and seedbeds, which tolerate less injury; any treatment goes on the ferns after harvest is over.[1][2]

Common questions

Why do my asparagus ferns look bushy and blue-green?
That witches'-broom growth is the classic sign of asparagus aphids feeding on the ferns.[1][2]
How do I keep asparagus aphids from coming back?
Cut down and remove the old ferns in fall or winter, since the eggs overwinter on them.[3][1]

Sources

  1. UMass Extension Vegetable Program, “Asparagus Aphid (vegetable fact sheet).” www.umass.edu/agriculture-food-environment/vegetable/fact-sheets/asparagus-aphid (accessed 2026-10-19)
  2. University of California Statewide IPM Program, “European Asparagus Aphid (UC IPM Pest Management Guidelines: Asparagus).” ipm.ucanr.edu/agriculture/asparagus/European-Asparagus-Aphid (accessed 2026-10-19)
  3. University of Connecticut Cooperative Extension, IPM Program, “Asparagus Aphid: Brachycorynella asparagi (J. Boucher).” ipm.cahnr.uconn.edu/asparagus-aphid-brachycorynella-asparagi (accessed 2026-10-19)
  4. iNaturalist, “Brachycorynella asparagi taxon page (order and family).” www.inaturalist.org/taxa/1088717 (accessed 2026-10-06)

Updated 2026-10-19. Built from sourced records. Spot an error? Tell us.