Bug FAQHairy Kelp Fly
Chaetocoelopa littoralis · Order: Diptera · Family: Coelopidae
The hairy kelp fly is a small, about 7 mm long, fly with long, hairy legs. It is grey with a broad head band, reddish-brown antennae and legs, and its wings are clear with brown veins. It lives on decaying seaweed and kelp washed up on New Zealand beaches, often forming large groups.
Source: Wikipedia
How to recognize it
The fly is grey with a broad band on the head, reddish-brown antennae, palpi, proboscis and legs, and has long black hairs on its legs and abdomen; its wings are clear with brown veins.
Source: Wikipedia
Size
Adults are about 7 mm long and have long, hairy legs.
Source: Wikipedia
What it eats
Larvae feed on decaying algae and the microorganisms associated with it.
Source: Wikipedia
Life cycle
Larvae pass through three instar stages before pupating in sand higher up the beach. Larger males have higher mating success because they can overcome female resistance behaviors.
Source: Wikipedia
Where it comes from
The species is endemic to New Zealand.
Source: Wikipedia
More photos
Questions people ask
What do the larvae eat?
They feed on decaying algae and its associated microorganisms.
Source: Wikipedia
Where can I find hairy kelp flies?
They are found on decaying seaweed and kelp washed up on New Zealand beaches, often in large groups.
Source: Wikipedia
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Chaetocoelopa_littoralis
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-23.