European Crane Flies are fairly large, semi-aquatic (as larvae) insects. Adults live only a short time whereas larvae may live for a year or more in moist soil conditions feeding on organic matter and plant tissue. They more commonly occur around bodies of water because of the requirement for damp soil. Most species go unnoticed except for the people who study them. A few, however, have adapted to survival in the relatively drier soils away from permanent water. These species are a concern when they feed on the roots of turfrass. In New York, they are most widespread in the western half of the Erie Canal corridor.
Biology & Impact
Adults are 2.5 - 3.0 cm long, pupae 3.0 - 3.5 cm, mature larvae 3 - 4 cm. They complete one or two generations a year, with the emergence of adults occurring over a period of several weeks at any one site, over the period of early spring and late July to September. Survival is favored under moist conditions. Active larvae mostly inhabit the top 3 cm of the soil where they feed on root hairs, root and crowns of turf. The larvae, known as leatherjackets, can be problematic in any grass-based system, from low-and high maintenance turf, like home lawns and golf courses, to production-based systems like sod farms and grass seed fields.
Control tactics should be directed against the larvae because adults are hard to target and short-lived. Suggested thresholds range from 15 to 50 larvae per sq.ft., depending on overall turf health. Because of their sensitivity to dry conditions, careful management of soil moisture levels may be a key cultural control tactic to reduce populations. Raking up larvae at night when they emerge to feed is also an option. There are also many control products registered for leatherjacket control in turfgrass of New York.