Leatherjackets are the larval stage of the cranefly (Tipula spp). Legless, brown-grey or earth-coloured and 4 cm long when fully grown. Adults start to hatch from pupae in late July/August and may be seen flying until September. After hatching they mate and the females lay eggs in the ground, a process which they accomplish in 24 hours. Eggs hatch in about 10 days and the new larvae start to feed on grass roots. During mild winters feeding can continue through the winter and into the following spring. Larvae stop feeding in May/June after which they will pupate close to the surface of the soil. Leatherjackets have one generation a year. Leatherjacket damage occurs from the autumn to spring but is most severe in the spring when the larvae are reaching maturity.