Threats to the US

Beech Bleeding Canker

**This organism is not known to be present in the United States but poses a threat.  Beech bleeding canker, a disease caused by the fungus-like Phytophthora kernoviae, is not known to be in the United States but may pose a serious risk to US plants should it be introduced. Rhododendrons and European beech are the primary disease hosts, but several other species of tree, shrub, and ornamental plant may be impacted or killed by this disease.

USDA surveys for this disease, and members of the Sentinel Plant Network support early detection efforts by monitoring for symptoms on potential host

Box Tree Moth

The box tree moth, Cydalima perspectalis, is not known to be present in the United States but poses a serious risk to our ornamental and landscape plantings if introduced. These insects attack a variety of boxwood species, commonly used in landscape plantings and for hedges and topiaries. While non-destructive in its native East Asian region, the larvae feed extensively on the leaves of boxwoods in nonnative regions, weakening and desiccating the plants. Dense moth populations often result in complete defoliation and death.

Japanese Oak Wilt

**This organism is not known to be present in the United States but poses a threat. Japanese oak wilt is a disease caused by the fungus — Raffaelea quercivora. It was discovered in 2002 in association with dying oak trees in Japan. The oak ambrosia beetle, Platypus quercivorus, feeds on the Raffaelea quercivora fungus and carries it to new hosts. Typically, ambrosia beetles and their associated fungi do not kill healthy trees; however this is not the case with Japanese oak wilt. Scientists now attribute the death of more than 200,000 oak trees to this disease, annually since 1980.

Japanese Pine Sawyer

The Japanese pine sawyer (JPS), Monochamus alternatus, is not known to be present in the United States but may pose a serious threat to our urban and forest ecosystems if introduced. Like other beetles in the genus Monochamus, Japanese pine sawyers breed in dying or weakened trees. In their native regions, these insects have historically been considered beneficial decomposers, but they could potentially be invasive pests of economic importance if introduced into the U.S. In Asia, JPS is a vector of the pinewood nematode, which causes fatal pine wilt disease.

Japanese Wax Scale

**This organism is not known to be present in the United States but poses a threat. Japanese wax scale is a soft scale insect native to east Asia that has been introduced across Europe and Asia. It is not known to be in the US, but poses a serious threat should it be introduced, especially in forested and citrus-growing regions.

Masson Pine Moth

**This organism is not known to be present in the United States but poses a threat. The Masson pine moth is a significant defoliator of natural and planted pine stands in southeastern Asia. Heavy defoliation from Masson pine moth has resulted in reduced growth and increased mortality. In the early 2000s it was considered the most economically damaging forest pest in southern China.

In addition to the economic and environmental damage it causes, Masson pine moth also causes health problems for many individuals who come in contact with the caterpillars or cocoons.

Mediterranean Pine Shoot Beetle

**This organism is not known to be present in the United States but poses a threat.  The Mediterranean pine shoot beetle feeds on pine trees. In years of drought or other stress, they can kill thousands of acres of pines. A closely related pine shoot beetle, Tomicus piniperda, has already caused substantial damage to forests in the northern US. Tomicus destruens occupies the climate niche south of T. pinniperda and could cause similar damage in the southern portions of the country. T. destruens is easily moved in wood packing material, and it is so cryptic that an introduction could easily be

Mountain Oak Longhorned Beetle

**This organism is not known to be present in the United States but poses a threat.  The mountain oak longhorned beetle is in the same family as the Asian longhorned beetle (Anoplophora glabripennis). It is native to China and far eastern Russia. It is not known to be in the US, but poses a serious threat should it be introduced, especially in the southeastern US. The mountain oak longhorned beetle feeds primarily in the xylem of its host trees, causing damage to the tree and its timber value. It attacks mainly oak species, but has also been known to feed on citrus, chestnut and other species.

Oak Processionary Moth

**This organism is not known to be present in the United States but poses a threat.  The oak processionary moth (OPM), Thaumetopoea processionea, is not known to exist in the United States but may pose a serious threat to oaks and other trees if introduced. The larvae of this high-consequence defoliator strip trees bare of leaves, making them vulnerable to other pests, diseases, and environmental stressors. These larvae may be seen at dusk, traveling in long nose-to-tail processions to feed in the canopy, and again at dawn when they return to their nests.

Oak Splendor Beetle

**This organism is not known to be present in the United States but poses a threat.  The oak splendor beetle is closely related to the emerald ash borer. It is not known to be in the US, but poses a serious threat should it be introduced, especially in the oak-rich eastern and western portions of the US. North America has the highest diversity of oaks in the world, and oaks produce acorns that are critical food for many kinds of wildlife. Oak splendor beetles lay their eggs under the bark of oak, chestnut and beech trees.

Rosy Moth

**This organism is not known to be present in the United States but poses a threat.  Rosy moth is a close relative of the European gypsy moth, Lymantria dispar; both are serious defoliating forest pests. It is not known to be in the US, but poses a serious threat should it be introduced to any forested region of the US. Rosy moth has a wide climate range, from subtropical to boreal, and is one of the most important defoliators in the ranges where it occurs (Europe, Asia and India), especially of oak species. It feeds readily on many North American tree species and also defoliates apple trees.

Scots Pine Blister Rust

**This organism is not known to be present in the United States but poses a threat.

Scots pine blister rust, a disease caused by the fungus Cronartium flaccidum, is not known to be present in the United States but may pose a serious risk to our forests and Christmas tree industry if introduced. Close relationships between known host trees and native hard pines raise concern that our trees could be highly susceptible to this exotic rust.

Siberian Silk Moth

**This organism is not known to be present in the United States but poses a threat. The Siberian silk moth is the most harmful defoliator of coniferous forests in North Asia. It does not yet occur in North America. It is able to attack and kill healthy plants and has been known to kill trees and forests across very wide areas. Outbreaks have occurred in China, Russia (particularly Asian and Siberian Russia and the Russian Far East), Japan, Mongolia, Poland and North and South Korea.

Siberian silk moth has a wide climate suitability range, making its survival likely in the northern US and

Tremex Wood Wasp

**This organism is not known to be present in the United States but poses a threat. The tremex wood wasp is native to Asia, where it attacks sick and dying trees mainly in the poplar and willow families. Outside its native range, however, it attacks healthy trees and can cause severe damage, mortality and economic loss. In Chile it attacks healthy poplar and boxelder trees, ruining their wood for lumber and removing windbreaks that protect agricultural fields. It has also caused damage in Australia since its introduction there.