PestControlBasics
Menu

Identify

Treat

Local

About

Asparagus Miner

Ophiomyia simplex[5]

The asparagus miner (Ophiomyia simplex) is a small fly brought to North America from Europe. It is found wherever asparagus grows and feeds on nothing else. Its maggots tunnel just under the surface of the stalks, mostly older stalks carrying ferns. The tunnels themselves do little harm, but the insect is linked to Fusarium, a fungus that causes crown and root rot.[1]

Group
Insect
Order
Diptera
Family
Agromyzidae
Sources
5 cited
Updated
2026-11-09

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

  • The adult is a shiny black fly only 3 to 4 mm long (about 1/8 inch), with clear wings.[1]
  • The maggot is whitish and legless, tapered at both ends, with black mouth hooks at the front.[1]
  • Look for mines just under the skin of the stalk, running up or down from where the eggs were laid, usually near the base of the plant. The brown pupa, 4 to 5 mm long and darkening with age, sits inside the mine.[1]

Where it lives

Introduced to North America from Europe, it is now present wherever asparagus is grown.[1]

Biology and life cycle

It overwinters as pupae inside old mines near or below ground level. Adults appear in May and lay eggs under the skin of the stems, usually near the base of the plant.[1]

There are two generations a year. First-generation maggots feed in June and pupate in their mines; second-generation adults lay eggs in late July or early August, and those maggots feed through August, pupate in the fall and overwinter.[1]

Development depends on temperature: it does not develop below about 12°C (54°F), and the pupal stage takes the longest. A degree-day model built from Michigan data predicts its life stages in the midwestern and eastern United States.[2]

At least 12 kinds of tiny parasitic wasps attack the pupae in Michigan asparagus fields; Chorebus rondanii and Thinodytes cephalon are the most common.[3]

Damage and signs

  • Several mines in one stalk can girdle it, but the feeding itself has little effect on yield.[1]
  • The bigger concern is disease: the miner is associated with Fusarium fungi and can carry them into the plant through its feeding wounds. Fusarium has been implicated in declining asparagus production worldwide.[1][2]

Health risk

It feeds only on asparagus; the sources describe it only as a crop pest.[1]

Control

Prevention

Choose Fusarium-resistant asparagus varieties. This is the most important step for limiting the asparagus miner's impact.[1]

Sanitation

Remove old stalks left over winter, where the pupae overwinter, and any wild asparagus near the planting.[1]

Biological control

Parasitic wasps attack the pupae, though their overall impact is not well known. The wasps lived twice as long when fed sugar-rich food, and researchers suggest conserving the two most common species. Field lures baited with synthetic asparagus plant odors drew parasitic wasps without drawing pests and may raise parasitism of the miner.[1][3][4]

Pesticides

There are no treatment thresholds for spraying, and the main controls are cultural. Commercial growers often use broad-spectrum insecticides without clear guidelines.[1][2]

Common questions

What are the thin tunnels under the skin of my asparagus stalks?
They are likely asparagus miner mines. The maggots tunnel just under the surface, up or down the stalk, and pupate inside the tunnel.[1]
Do I need to spray for asparagus miner?
Usually not. Its feeding has little effect on yield, there are no treatment thresholds, and the main controls are removing old stalks and planting Fusarium-resistant varieties.[1]

Sources

  1. UMass Amherst Center for Agriculture, Food, and the Environment (Extension Vegetable Program), “Asparagus Miner (vegetable fact sheet; last updated March 23, 2015).” ag.umass.edu/vegetable/fact-sheets/asparagus-miner (accessed 2026-11-09)
  2. Pest Management Science (via NCBI PubMed), “The development of the asparagus miner (Ophiomyia simplex) in temperate zones: a degree-day model (Pest Management Science, 2014; abstract).” pubmed.ncbi.nlm.nih.gov/24038945/ (accessed 2026-11-09)
  3. Environmental Entomology (via NCBI PubMed), “The parasitoids of the asparagus miner (Diptera: Agromyzidae): field parasitism and the influence of food resources on life history (Environmental Entomology, 2014; abstract).” pubmed.ncbi.nlm.nih.gov/25313948/ (accessed 2026-11-09)
  4. Environmental Entomology (via NCBI PubMed), “Biological control of asparagus pests using synthetic herbivore-induced volatiles (Environmental Entomology, 2019; abstract).” pubmed.ncbi.nlm.nih.gov/30496371/ (accessed 2026-11-09)
  5. iNaturalist, “Ophiomyia simplex taxon page (order and family).” www.inaturalist.org/taxa/552003 (accessed 2026-11-09)

Updated 2026-11-09. Built from sourced records. Spot an error? Tell us.