Adult crane flies (Tipulidae spp.) feed only on nectar or other liquids. The larvae of the crane fly, called 'leatherjackets,' are much more voracious. They are relatively large, soft, and fat, and they feed on various plants, including the base of the root of grasses and certain varieties of cabbage and grain. As may be expected, they can cause a great deal of damage.
The crane fly goes through six stages of development: the egg stage, four larval stages, and an adult stage. Adult crane flies only live for a few days. Some species have one generation per year, while others go through several generations in a year. This means that larvae can be found - and can do damage to crops - year-round.
- During the day, the leatherjackets remain underground. They surface at night and eat the base of the root, the base of the stem, and the lower green parts of the plant. They also pull the plant slightly underground. If a plant's stem has been partially eaten, it withers.
- If large numbers of leatherjackets eat at the root bases of grasses, large brown spots will appear in the expanse of grass.
- Extensive secondary damage can occur if birds forage for leatherjackets in the soil.