Summary

Invasive species affect every region of New York State. Across the U.S., more than 4,500 non-indigenous species have established self-sustaining populations and pose a serious threat to agriculture, human health and the ecological integrity of our lands and waters.

The Issue

The economic and ecological impacts of invasive species are enormous. According to the New York State Invasive Species Task Force (2005), a coordinated statewide effort will be essential if New York is to meet the challenge. Cornell researchers and extension educators are conducting considerable invasive species research and educational programming. The following are some of the invasive species-related research and outreach efforts underway at the College of Agriculture and Life Sciences (CALS). They fall into six main categories: human and animal health, ornamentals and turf, agricultural commodities, rural and urban forests, aquatics, and natural areas and wetlands.

Impacts

Human and Animal Health

Predicting the Risk of West Nile Virus

Cornell University scientists launched a full-scale study on the influence of climate on mosquito populations that transmit diseases such as West Nile virus (WNV) to humans. The research provides a mechanism for early warning of WNV risk, serves as a model for other existing and future vector-borne diseases, and can be readily used by public health professionals for decision-making.

The correlation of climate data with previously acquired information provides scientific clues to how mosquito populations develop and age. Older mosquitoes carry WNV, becoming infected when they feed on “reservoir” animals, such as birds. During subsequent blood meals after incubation, the mosquitoes inject the virus into humans and animals, where it can multiply and cause illness. Outdoor temperatures determine both the rate the virus replicates in the mosquito and the rate mosquitoes age. (Laura Harrington, Entomology; Arthur DeGaetano, Earth and Atmospheric Sciences; Katherine McComas, Communication)

Reducing Mosquito Habitats

The presence of mosquito species breeding in agricultural “bunker tires” on dairy farms in New York State was evaluated by entomologists at Cornell, who found 12 species of mosquitoes. All but two of these species have been found naturally infected with arboviruses and could be important vectors affecting human and animal health. One new species found in this habitat is an invasive mosquito introduced to the Eastern U.S. from Japan and Korea in the late 1990s. The mosquito is highly competent to transmit West Nile virus (WNV) and other pathogens to human hosts. Over the past five years, this species has spread throughout much of New York State. Control and containment of the spread of this species in non-traditional habitats should become a major priority in vector control and WNV surveillance programs. (Phillip Kaufman, Laura Harrington and Donald Rutz, Entomology; Keith Waldron, NYS IPM Program)

Global Warming and Range Expansion of Invasive Mosquitoes

The Asian Tiger mosquito was first introduced to the U.S. in the mid-1980s from Asia. This species is a competent transmitter of at least 22 different viruses that impact human and animal health. Currently this mosquito is limited by cold winter temperatures in New York State and has not become well established. By measuring the limits of cold tolerance for this species in the laboratory and field, and using projected temperatures for New York State based on global warming estimates, the range expansion and relative human disease risk for the state can be estimated. (Beth Meccariello and Laura Harrington, Entomology; Arthur DeGaetano, Earth and Atmospheric Sciences)

Ornamentals and Turf

Viburnum Leaf Beetles are Back, Hungrier than Ever

The viburnum leaf beetle devastated large swaths of native and imported viburnum species in 2004 and 2005, and continues to chow down on susceptible viburnum shrubs in New York State and New England . Paul Weston, a Cornell senior research associate who specializes in pests that attack woody ornamentals, is conducting several studies of biological control and minimally toxic control methods. In new plantings, he recommends planting non-susceptible varieties. The leaf beetle has already invaded 39 of New York’s 62 counties as well as Maine, Vermont, New Hampshire, Pennsylvania, Massachusetts, Connecticut, and Ohio. Cornell entomologist E. Richard Hoebeke has been tracking the beetle since its first public appearance in New York in July 1996 in northern Cayuga County. (Paul Weston and E. Richard Hoebeke, Entomology)

Crane Flies Threaten Lawns, Golf Courses and Pastures

European crane flies look like oversized mosquitoes. The good news is they don’t bite. The bad news is they can severely damage all types of turfgrass and forage grass species and are known to attack seedling nurseries and a wide range of vegetable and small fruits crops. There are 3.4 million acres of turfgrass in the state and the turfgrass industry contributes $5.1 billion to the state’s economy each year. The arrival of two species of European crane fly in 2004 is of major significance to the golf industry and other sectors of the turfgrass industry, according to Daniel Peck, Cornell turfgrass entomologist. He is currently testing various chemical and biological pesticides with the hope he can make recommendations when the crane fly larvae are on the attack. Together with information on their ecology and range expansion in New York State, Peck’s extension and applied research is working to alert and arm the Northeast in advance of exotic crane fly outbreaks. (Daniel Peck, Entomology)

Agricultural Commodities

Bracing for an Invasion of Swede Midge

A tiny, voracious fly called the swede midge wreaked havoc across Eastern Canada’s cabbage and broccoli fields, and is now in New York State . Although nearly undetectable to the naked eye, the swede midge poses a major threat to the Empire State ’s cabbage crop, valued at $87 million annually, and the state’s $6 million annual crop of broccoli, Brussels sprouts, cauliflower, Chinese cabbage, and related crops. Agricultural scientists and extension educators at Cornell are working to keep the swede midge under control by scouting for the insect, educating farmers, publishing an identification guide, sending fact sheets to all crucifer growers in New York, and developing tactics to manage it.

(Christine Hoepting and Julie Kikkert, Cornell Cooperative Extension; Tony Shelton, Entomology)

Combating Invasive Soybean Aphids with Biological Controls

Soybean aphids are native to China but were first found in North America in 2000. This new pest can rapidly increase in number to very high population densities, reducing soybean pod set and plant height, and causing major yield losses. In addition, soybean aphids can vector soybean viruses. Entomologists at Cornell have documented eight species of native fungal pathogens and several species of parasitoids that attack soybean aphids. In some cases, control by these beneficial organisms was high enough that soybean aphids were controlled naturally, without sprays. The goal of the project is to develop cropping methods that utilize biological controls so growers do not have to spray insecticides. Until the introduction of the soybean aphid, soybean was considered a crop with virtually no important insect pests in the U.S. (Ann Hajek, John Losey, and Keith Waldron, Entomology)

Rural and Urban Forests

Fighting the Invasion of Asian Longhorned Beetle

The Asian longhorned beetle (ALB), a native of China and Japan, “hitchhiked” to North American port cities in solid wood packing material. In its larval stage, the beetle bores into live trees, girdles their vascular system, and ultimately causes death of the tree. It prefers deciduous hardwoods, such as maple, birch, horsechestnut, elm and poplar. U.S. federal and state governments have already spent over $168 million for control and removal of infested trees. The USDA’s Animal and Plant Health Inspection Service (APHIS) estimates that the beetle could potentially cause over $41 billion in damages to the timber, maple syrup, nursery, and tourism industries. Other estimates of the impact, direct and indirect, of potential ALB infestation in all U.S. urban areas have reached over $650 billion.

Cornell University scientists have been at the forefront of the fight to track and control ALB. Entomologist E. Richard Hoebeke was the first to officially identify the beetle in 1996 from a sample collected in Brooklyn, NY Hoebeke, along with state and federal agencies, continues to conduct identification and delimiting surveys in port cities on North American shores to discover any new outbreaks of ALB and other exotic insects.

With a grant from USDA’s Agricultural Research Service (ARS) in 1998, Hoebeke co-authored a comprehensive, illustrated handbook of the beetle’s genus group. This handbook has been made available for use by port-of-entry officials and other scientists around the globe to help identify the beetle, understand its biology and life cycle, and consequently help prevent further infiltration of this species (and related species) into non-native environments. (E. Richard Hoebeke, Entomology)

Alien Woodwasp Could Threaten Nation’s Pine Trees

Despite dozens of interceptions at U.S. ports, a public enemy has infiltrated the nation’s borders. A single specimen from Fulton, NY , was identified by Cornell senior extension associate E. Richard Hoebeke as the alien woodwasp. Subsequent surveys have found it in five New York counties and along the St. Lawrence River in Canada. These discoveries raised red flags across the nation because the invasive insect species has devastated up to 80 percent of the pine trees in areas of New Zealand, Australia, South America, and South Africa . The woodwasp, which is native to Europe, Asia, and Northern Africa, kills pines and other conifers by introducing a toxic mucus and spores of a toxic fungus when the female lays her eggs through the bark and into the sapwood of the tree. A biological control method using a parasitic nematode has been remarkably effective in other countries where the woodwasp has been accidentally introduced. (E. Richard Hoebeke, Entomology)

Aquatics

Muscling Zebra Mussels Aside

Zebra mussels are small black-and-white striped bivalve mollusks that have invaded North American fresh waters and estuaries. Indigenous to the Aral, Black and Caspian Seas, biologists suspect they “hitchhiked” to the Great Lakes in the ballast water of European cargo ships. Since their initial discovery in 1988, zebra mussels have spread throughout all the Great Lakes, the St. Lawrence Seaway, the Mohawk and Hudson Rivers, and into 21 other states and two Canadian provinces. The mussels are filter feeders and can colonize almost any surface, including metal, rubber, glass, and cloth. In the Great Lakes Region alone, they have negatively impacted, to the tune of hundreds of millions of dollars, facilities that use raw surface water such as utility plants, factories, and water treatment plants; boat and marina owners; recreationalists who are driven from beaches by the smell of dead, rotting mussels; and Great Lakes fisheries. Zebra mussels are one of the invasive aquatic species studied by Cornell researchers and monitored by the New York Sea Grant Extension, a state and federally-funded program that provides science-based information to people making and influencing decisions for the wise development, management, and use of coastal resources. (Charles O’Neill, Sea Grant)

Making Information On Invasive Species Available in NY and Across the Globe

Since 1990, Cornell Cooperative Extension/Sea Grant staff have directed and operated the National Aquatic Nuisance Species Clearinghouse (NANSC), a special international library of research, public policy, and outreach education resources pertaining to invasives in North American water environments. Located in Brockport , NY , NANSC archives over 7,600 publications in its technical collection; it is perhaps the most extensive collection on aquatic nuisance species in the world. Through NANSC resources and programs, industry, government, communities, municipalities, non-profit groups, academia, and the media are informed about important marine and freshwater nuisance, non-indigenous and invasive species of North America . The NANSC publishes the quarterly research digest Aquatic Invaders. A searchable electronic database of its technical library bibliography is accessible through its website www.aquaticinvaders.org. The website receives more than 100,000 hits monthly from researchers and government agencies in 95-plus nations, with materials sent regularly to 25 countries outside North America .

Recent efforts of the NANSC include inventorying all laws and regulations that apply to the spread, control and management of the water chestnut in the Northeast, and updating the annual and cumulative economic effects of zebra and quagga mussels on drinking water and power generation facilities in North America. (Charles O’Neill, Sea Grant)

Natural Areas and Wetlands

Biological Control of Invasive Plants in Natural Areas

In addition to documenting the negative ecosystem effects of invasive plants, researchers at Cornell develop biological control programs for a number of different invasive species (purple loosestrife, garlic mustard, Japanese knotweed, Phragmites, and water chestnut, to name a few). Careful use and implementation of biological control, along with the training of land managers, can restore invaded communities.

This management approach has been successfully implemented to control purple loosestrife across North America. Thousands of acres of invaded wetlands are presently being restored. Herbicidal treatments to suppress invasive plants would cost millions of dollars annually. For purple loosestrife alone, the single largest infestation in Washington State would require $800,000 annually for herbicide treatment.

The development of biological control (approximately $1 million in development costs) for purple loosestrife has allowed wetland managers to deploy millions of leaf-feeding beetles across North America in 35+ states. The attack of these herbivores is reducing purple loosestrife abundance across the continent and saving millions of dollars in control costs. In addition, native plants and animals are re-colonizing formerly uninhabitable wetlands. Pesticide input into sensitive wetlands has been greatly reduced. The beetles do not survive once the loosestrife is gone, so there is no risk of replacing one invasive with another. (Bernd Blossey, Natural Resources)

Preventing and Responding to Invasive Aquatic Plant Infestations

Invasive aquatic plants like water chestnut wreak ecological and economic havoc on water bodies in the Oswego River Basin, negatively impacting fisheries, native aquatic species, recreation, and waterfront property values. In the U.S., $100 million is invested annually in non-indigenous aquatic weed control, while millions in potential tourism dollars are lost when species invade recreational areas. The most cost-efficient and environmentally friendly strategies combine prevention, early detection, and rapid response.

Portions of the Oswego River Basin are already infested with water chestnut, and the whole basin is vulnerable to a host of other invasive aquatics. Cornell Cooperative Extension (CCE)-Onondaga and CCE-Cayuga have been working regionally to enlist and educate volunteers in the prevention, early detection, and appropriate control of water chestnut and other invasive aquatic plants.

Cornell researchers have been studying control methods on Oneida Lake at Cornell’s Shackelton Point Biological Research Station. Researchers have mapped the problem and identified areas suitable for removal via volunteers. Workshops were held on control and prevention techniques to manage water chestnut and train volunteers in hand-pulling control techniques and mapping using Global Positioning Systems.

Some impacts from CCE-Onondaga and CCE-Cayuga activities: 49 Weed Watch Out! Volunteers were trained, including people from Owasco Lake, Skaneateles Lake, Oneida Lake, Onondaga Lake, and the Three River System; to date, two-thirds of Oneida Lake, all of Onondaga Lake, and part of Skaneateles Lake and the Three River System have been adopted by volunteers who monitor for water chestnut—all with impressive results. Volunteers from the Oneida Shores Rotary Club removed most of the water chestnut not killed by a chemical treatment on the Western end of Oneida Lake. Volunteers on Onondaga Lake and Oneida Lake reported previously unknown populations in outlets or inlets to the lakes, and about a dozen members of the Onondaga Yacht Club worked on two separate days to remove populations of water chestnut in the outlet of Onondaga Lake. (Amy Samuels, Onondaga County Cooperative Extension)

Emerging Threats

In addition to the invasive species already mentioned, others, like Sudden Oak Death, snakehead fish, giant hogweed, oriental bittersweet, Japanese knotweed, Phragmites, southern bacterial wilt, soybean rust, chronic wasting disease, and emerald ash borer pose threats in New York now, or are poised for entry.

Resources, Partners and Regional Networks

At Cornell, researchers work on the detection, eradication, containment, and management of many invasive species. And Cornell Cooperative Extension, with offices in every county, is positioned to help educate and engage citizens about invasives.

There are also several diagnostic labs for plant and animal pathogens and insects on the Cornell campus, including the new $2.3 million quarantine facility at the College of Agriculture and Life Sciences where research can be safely conducted on invasive pests and their natural enemies. Additionally, Cornell is the designate Northeast Regional Center for the National Plant Diagnostic Network and co-leads, with Penn State, the Northeast Regional Integrated Pest Management Center. The Cornell College of Veterinary Medicine is the site for the NYS Animal Health Diagnostic Center, which seeks to prevent communicable diseases of conditions that impact human health.

Researchers from Cornell work in partnership with New York State and federal agencies such as the NYS Department of Agriculture and Markets, the NYS Department of Environmental Conservation, the NYS Department of Health, the U.S. Department of Agriculture, SUNY institutions, and many others.

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Contact

Michael P. Hoffmann

Professor of Entomology and Director Cornell Agricultural Experiment Station
College of Agriculture and Life Sciences
Cornell University
Ithaca, NY 14853

Phone: 607-255-2552
Email: mph3@cornell.edu