Bug FAQNew Zealand dobsonfly
Archichauliodes diversus · Order: Megaloptera · Family: Corydalidae
Also called: New Zealand Fishfly, Toe biter
The New Zealand dobsonfly (Archichauliodes diversus) is an aquatic insect whose larvae hatch at about 2 mm and can grow to nearly 4 cm. Adults emerge after 2 to 5 years and are active at night from early July to late January. Larvae are predatory, using large serrated mandibles to catch mayfly nymphs and other small aquatic invertebrates, even members of their own species.
Source: Wikipedia
How to recognize it
The head and thorax are black and flattened with a large set of mandibles; the abdomen is long, light-coloured and bears eight pairs of tentacle-like gills.
Source: Wikipedia
Size
Larvae hatch at roughly 2.2 mm and can grow to about 38.5 mm before pupating.
Source: Wikipedia
Where it lives
It thrives in good-quality, well-oxygenated water.
Source: Wikipedia
What it eats
Larvae are predatory, using their large serrated mandibles to capture aquatic invertebrates, especially mayfly naiads, but will also eat almost anything smaller, including conspecifics.
Source: Wikipedia
Life cycle
Larvae live in water while adults are terrestrial, and the insect spends most of its 2 to 5-year life in the aquatic juvenile stage.
Source: Wikipedia
When you see it
Adults are nocturnal, most active at dusk and night, from early July to late January, a period of about 15 weeks.
Source: Wikipedia
Lookalikes
Although often called a New Zealand dobsonfly, it belongs to the fishfly subfamily Chauliodinae and is not a true dobsonfly.
Source: Wikipedia
More photos
Questions people ask
When are adult New Zealand dobsonflies active?
Adults are active at night from early July through late January, lasting about 15 weeks.
Source: Wikipedia
What do the larvae eat?
Larvae are predators that hunt mayfly nymphs and other small aquatic invertebrates, even eating members of their own species.
Source: Wikipedia
Where is Archichauliodes diversus found?
It is native and endemic to New Zealand, occurring throughout both the North and South Islands.
Source: Wikipedia
What habitat does this insect prefer?
It lives in clean, well-oxygenated freshwater streams and rivers.
Source: Wikipedia
Same family (Corydalidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Archichauliodes_diversus
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.