Archichauliodes diversus is the only species of dobsonfly in New Zealand, and it is common throughout the country. You are most likely to find it in its larval form – commonly known as ‘toe biters’. The larvae are found in stony or hard-bottom streams nationwide in bush-covered or farmland areas. Its ideal habitat is large rockpools with an overhanging bush canopy that provides shelter. It thrives in good-quality water and is the largest larvae of any New Zealand freshwater insect.
The larvae are voracious predators of other aquatic invertebrates, such as mayflies and caddisflies, which they ambush and catch using their large mandibles.
Like many other insect species, an adult dobsonfly has a very short lifespan of about 6–10 days. The adult form uses its ability to fly to locate mates, and females can lay hundreds of eggs on stream banks and rocks before they die.
Images: Adult dobsonfly by Lloyd Esler, CC BY-NC 4.0 and larvae by David Wilson, CC BY-NC 4.0. Both sourced from iNaturalist NZ.
