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Surveying Invasive Crane Flies

Two species of invasive crane flies were first detected in the Eastern United States, in Western New York, in 2004. Seneca Park Zoo Keepers and staff from the University of Rochester Cardiovascular Research Institute (CVRI) teamed up in September 2010 to participate in a population survey of crane flies under the direction of Dr. Matt Petersen, Dr. Dan Peck and Deb Marvin from the Department of Entomology at Cornell University. These budding entomologists captured crane flies at two three-acre study sites in lower Seneca Park as well as the CVRI campus in Brighton. 

We submitted samples for DNA analysis to scientists at Cornell University's Soil Insect Ecology and Turfgrass Entomology Lab, to compare methods of morphological and DNA identification techniques for the two invasive European crane flies (Tipula paludosa and T. oleracea). These exotic, invasive flies, which are native to northwestern Europe, were first detected in Nova Scotia in 1955. They likely first arrived in dry-soil ballast from shipping vessels and moved across Canada in potted plants contaminated with their larvae (known as leatherjackets). Over the subsequent 55 years, their range expanded through Ontario, Canada into the northeastern United States. 

The soil-dwelling larvae of the European crane flies have been known to damage cereal, sugar beet, turnip and carrot crops, hay fields, pastures and turf grass. Our native crane flies in contrast are less injurious to these plant systems. Adult crane flies (which look like giant mosquitoes) are often seen swarming over turf grass during their three-day breeding cycle in early spring and late summer. These invasive crane flies are difficult to tell apart from our native crane flies without the aid of a magnifying glass or mitochondrial DNA sequencing. Efforts to curtail expansion of the invasive crane flies across the United States emphasize restriction of movement of larvae in contaminated soil and sod from Europe, Canada and Western NY to other unaffected regions.

The population surveys being conducted across all of New York State this fall will assist wildlife and agricultural scientists to target and monitor control measures. We have learned many lessons from other invasive animals (zebra mussels and mute swans) and plants (purple loose strife and water chestnut) introduced inadvertently through commercial or ornamental activities. Our most successful and cost-effective interventions must prioritize prevention of introduction of invasive species. After they are here, exotic invasive species often compete with their native counterparts making eradication difficult.

2010 survey results:

Our team submitted 89 crane flies for analysis. Of those 89, we found three species.

  • Two species (Nephrotoma sp., accounting for two flies and Tipula paterifera accounting for 23 flies) were non-invasive.
  • One species (Tipula paludosa, accounting for 54 flies) were invasive.