crane fly dangling its long legs in slow erratic flight

Size
Body: 1–3 cm
Lifespan
1–2 years
Diet
Larvae (leatherjackets) feed on roots, decaying vegetation and organic matter in soil. Adults may feed on nectar or do not feed at all. Important food source for birds.
Habitat
Damp grasslands, forests and gardens. Adults often seen hovering near lights or resting on walls with extremely long legs splayed out. Larvae (leatherjackets) live in soil and rotting wood, feeding on roots and decaying organic matter.
Range
Throughout North and South Islands in damp grasslands, forests, wetlands and gardens. Most common in lowland areas with moist soils.
Endemism
Native
Main Threats
Habitat loss from drainage of wetlands, intensive agriculture and urban development. Larvae sensitive to soil compaction and pesticide use which reduces food sources.
Population
Abundant worldwide, with many native species in New Zealand. Harmless to humans, though larvae can occasionally damage pasture grass in high numbers. Crucial food source for birds and bats.
Conservation Status
Not Threatened
The gangly teenager of the insect world. With impossibly long legs that seem to detach at the slightest touch and a body that looks like a mosquito on stilts, the cranefly cuts a comical figure. Its legs are designed to break off. They have weak joints that snap under tension, allowing the fly to escape predators while the attacker is left holding a twitching limb. The fly can lose several legs and still fly, mate and lay eggs. Unlike the mosquito, the cranefly does not bite, sting or drink your blood. Most adults do not eat at all. They live for a few days solely to mate, running on stored energy from their larval stage. They are essentially flying reproductive machines with a severe case of awkwardness. Their flight is erratic and clumsy. They bounce off walls, bump into lamps and crash into windows. It is not grace they are after. It is speed. The larvae are called leatherjackets. They are grey, legless grubs with a tough, leathery skin that protects them from drying out. They live in soil or rotting wood, feeding on decaying plant matter and roots. They are vital recyclers, breaking down organic material and aerating the soil. But in large numbers, they can damage pasture grass, lawns and garden plants. Cranefly larvae are an important food source for birds. Starlings, blackbirds and thrushes probe the soil for them. Kiwi and weka eat them too. The larvae are also parasitised by nematodes and wasps, a natural control that keeps populations in balance. Adult craneflies emerge in summer and autumn. Males swarm at dusk, dancing in clouds above lawns and fields. Females fly into the swarm, and mating happens in the air. After mating, the female lays her eggs in damp soil or moss, pushing her sharp ovipositor deep into the ground. She may lay several hundred eggs before dying. Craneflies are found from sea level to the alpine zone. Some species have larvae that live in streams, feeding on algae and detritus. Others are adapted to wetlands, coastal dunes and even seeps on cliff faces. They are diverse, widespread and often overlooked.