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Woody Ornamentals Entomology @ Cornell University

Information on recent exotic pest arrivals in the U.S.
compiled by Paul A. Weston, Department of Entomology, Cornell University

Common name Scientific name Order: Family Description and history Quarantine pest?

viburnum leaf beetle Pyrrhalta viburni Coleoptera: Chrysomelidae This small beetle causes defoliation of a number of species of viburnum in both the adult and larval stage. First seen in New York in 1996, the pest has now spread to 27 counties in New York and was found during 2000 in adjoining Erie County, PA and Chittenden County, VT. Native to Europe. A number of insecticides will control the pest, but the most effective are systemic insecticides with long residual life, especially imidacloprid (Merit or Marathon). Some have suggested horticultural oil as a control method, but we have found this to be ineffective. NO

Asian longhorned beetle Anoplophora glabripennis Coleoptera: Cerambycidae This pest, native to China, has received lots of press lately for good reason. It is capable of killing large trees, and is particularly fond of many tree species that have been used as street trees in many U.S. cities (all species of maple, particularly sugar; elm; willow; horsechestnut; and most other hardwoods). Oaks are not suitable hosts. The only populations of the pest in the U.S. are in the New York City area (Manhattan, Brooklyn, and Queens), central Long Island (Amityville, Lindenhurst, and Islip), and several suburbs of Chicago. Systemic insecticides are being evaluated for control, but until the results are in from those trials, infested trees are cut, chipped, and burned. YES

pine shoot beetle Tomicus piniperda Coleoptera: Scolytidae This European native first showed up in the U.S. near Cleveland, OH around 1990, and has now spread throughout the states bordering the Great Lakes. It was found in St. Lawrence County for the first time in 2000, and exists in all New York counties to the south and west of St. Lawrence County. Adults feed on shoots, causing flagging; although not damaging to the health of the tree, it does result in cosmetic damage that is of concern to Christmas tree growers. This is a quarantine pest, so trees cannot shipped out of counties where the pest has been found unless they are inspected. Control is best achieved by eliminating breeding sites (downed or dying trees, logs, etc.) YES

hemlock woolly adelgid Adelges tsugae Homoptera: Adelgidae This east Asian native is now widely distributed in the eastern U.S., and is destroying hemlocks in the landscape as well as old-growth, full-grown trees. The insect is easily detected by the presence of fluffy white egg masses as well as nymphs and adults feeding along the length of twigs where needles arise. Control may be difficult, but recent findings suggest that systemic insecticides such as imidacloprid (Merit) may be effective. If left uncontrolled, trees will usually die in a matter of a few years. It appears that the strain of the pest in the U.S. is warm adapted and may not be able to spread much further north than the southern Adirondacks, but other populations of the pest in Japan occur in colder climates. Thus, the pest could evolve to spread further here than it currently appears able, and vigilance should be maintained. NO

Japanese cedar longhorned beetle Calidiellum rufipenne Coleoptera: Cerambycidae This pest, native to eastern Asia, was first found in the U.S. in North Carolina in 1997, and is now found throughout most of Connecticut and portions of Long Island, Rhode Island, and northern New Jersey. Originally thought to infest only dead or dying trees, it is now known to infest living trees in the Cupressaceae family, primarily cedars and arborvitae. Larvae feed under the bark, creating sinuous ridges along the trunk and large branches. Larval feeding disrupts flow of nutrients in the vascular tissue, resulting in branch dieback. Stress seems to be a major predisposing factor, so every attempt should be made to minimize stress, particularly drought stress in nurseries or after transplanting. NO

red-haird bark beetle Hylurgus ligniperda Coleoptera: Scolytidae This tiny beetle was first found in New York State in the Rochester area in 1994, and is now found in neighboring Wayne and Ontario counties as well. This pest is of little concern for healthy trees, but can spread pathogenic fungi to stressed host trees (several species of pine). Stress avoidance and sanitation (removal of dying and downed trees as well as stumps and slash) are the best methods of control. NO

pine woodwasp Sirex noctilio Hymenoptera: Siricidae This tree-killing woodwasp (horntail) was found for the first time in North America in September of 2004. Large-scale trapping revealed that the insect is more widely distributed than first thought (as of October 2005, the insect had been found in 5 counties in upstate NY--Cayuga, Onondaga, Oswego, Seneca, and Wayne). Eggs are laid in species of hard pine; host species include Scots pine, Austrian pine, pitch pine, Monterey pine, and loblolly pine, among others. Stressed trees are usually attacked. In addition to eggs, females deposit a toxic mucus and spores of Amylostereum areolatum, a vascular wilt fungus, in host trees, and these latter two agents are the cause of death of the tree. Signs of infestation include resin flow on bark and wilting/yellowing of pine foliage. Emerging wasps leave exit holes (1/8 to 3/8" in diameter) in the trunk, usually around chest high. NO

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Common name	Scientific name	Order: Family	Description and history	Quarantine pest?
viburnum leaf beetle	Pyrrhalta viburni	Coleoptera: Chrysomelidae	This small beetle causes defoliation of a number of species of viburnum in both the adult and larval stage. First seen in New York in 1996, the pest has now spread to 27 counties in New York and was found during 2000 in adjoining Erie County, PA and Chittenden County, VT. Native to Europe. A number of insecticides will control the pest, but the most effective are systemic insecticides with long residual life, especially imidacloprid (Merit or Marathon). Some have suggested horticultural oil as a control method, but we have found this to be ineffective.	NO
Asian longhorned beetle	Anoplophora glabripennis	Coleoptera: Cerambycidae	This pest, native to China, has received lots of press lately for good reason. It is capable of killing large trees, and is particularly fond of many tree species that have been used as street trees in many U.S. cities (all species of maple, particularly sugar; elm; willow; horsechestnut; and most other hardwoods). Oaks are not suitable hosts. The only populations of the pest in the U.S. are in the New York City area (Manhattan, Brooklyn, and Queens), central Long Island (Amityville, Lindenhurst, and Islip), and several suburbs of Chicago. Systemic insecticides are being evaluated for control, but until the results are in from those trials, infested trees are cut, chipped, and burned.	YES
pine shoot beetle	Tomicus piniperda	Coleoptera: Scolytidae	This European native first showed up in the U.S. near Cleveland, OH around 1990, and has now spread throughout the states bordering the Great Lakes. It was found in St. Lawrence County for the first time in 2000, and exists in all New York counties to the south and west of St. Lawrence County. Adults feed on shoots, causing flagging; although not damaging to the health of the tree, it does result in cosmetic damage that is of concern to Christmas tree growers. This is a quarantine pest, so trees cannot shipped out of counties where the pest has been found unless they are inspected. Control is best achieved by eliminating breeding sites (downed or dying trees, logs, etc.)	YES
hemlock woolly adelgid	Adelges tsugae	Homoptera: Adelgidae	This east Asian native is now widely distributed in the eastern U.S., and is destroying hemlocks in the landscape as well as old-growth, full-grown trees. The insect is easily detected by the presence of fluffy white egg masses as well as nymphs and adults feeding along the length of twigs where needles arise. Control may be difficult, but recent findings suggest that systemic insecticides such as imidacloprid (Merit) may be effective. If left uncontrolled, trees will usually die in a matter of a few years. It appears that the strain of the pest in the U.S. is warm adapted and may not be able to spread much further north than the southern Adirondacks, but other populations of the pest in Japan occur in colder climates. Thus, the pest could evolve to spread further here than it currently appears able, and vigilance should be maintained.	NO
Japanese cedar longhorned beetle	Calidiellum rufipenne	Coleoptera: Cerambycidae	This pest, native to eastern Asia, was first found in the U.S. in North Carolina in 1997, and is now found throughout most of Connecticut and portions of Long Island, Rhode Island, and northern New Jersey. Originally thought to infest only dead or dying trees, it is now known to infest living trees in the Cupressaceae family, primarily cedars and arborvitae. Larvae feed under the bark, creating sinuous ridges along the trunk and large branches. Larval feeding disrupts flow of nutrients in the vascular tissue, resulting in branch dieback. Stress seems to be a major predisposing factor, so every attempt should be made to minimize stress, particularly drought stress in nurseries or after transplanting.	NO
red-haird bark beetle	Hylurgus ligniperda	Coleoptera: Scolytidae	This tiny beetle was first found in New York State in the Rochester area in 1994, and is now found in neighboring Wayne and Ontario counties as well. This pest is of little concern for healthy trees, but can spread pathogenic fungi to stressed host trees (several species of pine). Stress avoidance and sanitation (removal of dying and downed trees as well as stumps and slash) are the best methods of control.	NO
pine woodwasp	Sirex noctilio	Hymenoptera: Siricidae	This tree-killing woodwasp (horntail) was found for the first time in North America in September of 2004. Large-scale trapping revealed that the insect is more widely distributed than first thought (as of October 2005, the insect had been found in 5 counties in upstate NY--Cayuga, Onondaga, Oswego, Seneca, and Wayne). Eggs are laid in species of hard pine; host species include Scots pine, Austrian pine, pitch pine, Monterey pine, and loblolly pine, among others. Stressed trees are usually attacked. In addition to eggs, females deposit a toxic mucus and spores of Amylostereum areolatum, a vascular wilt fungus, in host trees, and these latter two agents are the cause of death of the tree. Signs of infestation include resin flow on bark and wilting/yellowing of pine foliage. Emerging wasps leave exit holes (1/8 to 3/8" in diameter) in the trunk, usually around chest high.	NO