backswimmer rowing upside down across the pond surface
- Size
- Length: 1–1.5 cm
- Lifespan
- 6–12 months
- Diet
- Predatory: feeds on small insects, mosquito larvae, tadpoles and even small fish. Uses piercing mouthparts to inject digestive enzymes then sucks out liquefied remains. Swims upside down.
- Habitat
- Still or slow-moving freshwater ponds, lakes, farm dams and ditches. The upside-down pirates of the water column, swimming on their backs just beneath the surface film, ready to ambush passing prey.
- Range
- Throughout North and South Islands in still or slow-moving freshwater habitats. Most common in lowland ponds, lakes and slow-flowing drains with abundant aquatic vegetation.
- Endemism
- Endemic
- Main Threats
- Water pollution from agricultural runoff. Pesticide use. Habitat destruction of wetlands and ponds. Sensitive to severe water quality degradation and loss of aquatic vegetation which provides cover for hunting.
- Population
- New Zealand has several native species of backswimmer. Widespread and common, though sensitive to severe pollution and pesticide runoff. Voracious predators, helping to control mosquito populations.
- Conservation Status
- Not Threatened
The rebel of the pond world, refusing to follow the conventional rules of swimming. While most aquatic insects swim right-side up, the backswimmer cruises on its back, using its long, oar-like hind legs to row effortlessly through the water. It hangs upside down from the surface tension, breathing through a silvery bubble of air trapped against its abdomen like a miniature diving suit.
It is a sleek, streamlined hunter, perfectly adapted for life in the open water. Do not let its small size fool you. This is a fierce predator. Armed with a sharp, piercing beak, it will attack prey much larger than itself, including tadpoles, small fish and other insects. It injects a potent venom that paralyses its victim and liquefies the insides, which it then sucks out with gruesome efficiency.
To humans, their bite is surprisingly painful, a sharp, stinging jab that earns them the nickname water bees. It is a stern reminder that even the tiniest creatures can pack a punch. They are masters of camouflage from below. Their pale bellies blend with the bright sky, hiding them from fish looking up.
From above, their dark backs merge with the murky depths. The backswimmer breathes by trapping a bubble of air under its wings, using it like a scuba tank. When the oxygen runs low, it surfaces to replenish the bubble, then dives back down.
The female lays her eggs on aquatic plants, inserting them into stems or leaves for protection. The nymphs hatch as miniature versions of the adults and begin hunting immediately. They grow through several stages, moulting as they increase in size.
They are the silent, inverted guardians of the pond, keeping the ecosystem in check one paralysed tadpole at a time. To disturb a pond and see a fleet of them dart away is to witness a squadron of tiny, upside-down fighter jets scrambling for action.