Stock Photo - Mating European craneflies in grass. European craneflies, tipula paludosa, are listed as invasive species and pests in the US as a problem for agriculture. host in perennial flowers, pasture, small fruit and vegetables. Immatures Leatherjackets feed on clover and emerge as adult craneflies between March and May. Craneflies can be found in clouds around meadows and ponds in early spring. These two craneflies hang between grass stems after a heavy rainfall in May. Wing lace detail with fairly close detail. Horizontal, Information from USGA and Washington State University. WSU gives control information for crop control.