Shore Flies 🐛

Minor Pest also: shoreflies, algae flies

Family ephydridae

At a glance

  • Looks like: Small dark flies on wet soil, trays, benches, or algae-covered surfaces
  • Tell-tale sign: They are associated with algae and standing moisture more than plant roots
  • Severity: Nuisance — a wetness/algae indicator, not usually a direct plant pest

How to identify

Shore flies are small dark flies often mistaken for Fungus Gnats. They are sturdier, stronger fliers, and usually hang around algae, wet benches, saucers, and soggy media. The larvae feed mostly on algae and organic film, not healthy plant roots.

Damage

They are mostly a nuisance and sanitation signal. Their presence means the growing area is staying too wet and algae-rich, which also favors fungus gnats and root problems.

Treatment (least-toxic first)

Following Integrated Pest Management:

  1. Dry the surface and remove standing water from saucers, trays, benches, and floors.
  2. Scrub algae from pots, benches, propagation trays, and hard surfaces.
  3. Improve drainage and airflow.
  4. Use sticky cards to monitor adults if needed.
  5. Do not treat like a root-feeding pest unless fungus gnats are also present.

Prevention

Avoid constant wet surfaces. Bottom-water carefully, empty saucers, and clean algae before it becomes habitat.

Affects (in this guide)

Wet houseplant shelves, propagation setups, greenhouses, and constantly moist containers

Sources