Invasive Crane Flies

in the Northeast

Two species of European crane flies were detected in New York State in 2004, representing the first report of these exotic species in the eastern United States.  While there are many similarities between the two species, certain differences in their biology are relevant enough that management practices need to be tailored to the particular species.

Native to northwestern Europe, T. paludosa (the “European crane fly”) has established in three separate geographic regions of North America, which includes the Canadian provinces of Nova Scotia (1955), British Columbia (1965) and Ontario (1996).  Native to central and southern Europe, T. oleracea (the “common crane fly”) has established in South America (Ecuador, 1999) and British Columbia (1998).  In the U.S., both species range from Washington to northern California, mostly west of the Cascades and in coastal areas.  In NY, they are most widespread in the western half of the Erie Canal corridor.  T. paludosa has been detected in Erie, Monroe and Niagara counties, while T. oleracea has been detected in Monroe, Niagara, Ontario, Onondaga, Oswego, Seneca and Wayne counties.  In spring 2006, T. oleracea was also detected in Nassau and Suffolk counties on Long Island; it is unclear whether this represents a separate introduction, or whether it is one end of a wide range that crosses the entire state.  Local observers date their likely presence in western NY back to 2002.  The arrival of T. paludosa was probably inevitable, given that this species is widespread and firmly established in southern Ontario.  While T. oleracea has not yet been reported from Ontario, it was detected in Michigan in 2005.  Both insects were probably introduced to North America via infested soil media.  Unless we build awareness and establish safeguards to curtail their range expansion, movement of sod, container stock and other materials could occasion spread of these exotic species locally and regionally, across NY and into New England.

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.  West of the Cascades, they are regarded as the most serious insect pests in lawns, pastures and hay fields.  All turfgrass and forage species appear to be susceptible.  Incidence of this pest is influenced less by host plant than by biological or physical habitat factors.  Overall, they are dependent on moist soil conditions, and survival is favored by mild winters and wet, cool summers.  In turfgrass, leatherjackets are favored in areas with thatch buildup and poor drainage.

In addition to grasses, leatherjackets have the potential to affect cereal and other crops in North America. In British Columbia they are serious pests in seedling nurseries, affecting not only transplant bare-root stock, but also container stock, where they girdle the stem at the soil line.  Elsewhere, they affect flowers and several types of vegetable and small fruits.  In their native range, they are injurious pests of spring and winter cereals and can become troublesome in a variety of minor crops ranging from sugar beets and turnips to brassicas, berries and carrots.