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Southern Pine Beetle

An adult southern pine beetle
Southern pine beetle

Southern pine beetle (SPB) is a bark beetle that infests pine trees. The beetle is small, only 2-4 mm in length (about the size of a grain of rice) and is red-brown to black in color.

This insect is native to the southeastern United States but has been expanding its range up the east coast in recent years. Warming of extreme winter temperatures has most likely contributed to this expansion.

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How SPB Damage Pine Trees

a tree with bark removed to show tunnels left by adult beetles
Galleries (tunnels) left by adult beetles

All pine trees are susceptible to an infestation of southern pine beetle, including pitch pine, red pine, and jack pine. In addition to pines, hemlocks and spruce may also be affected in highly infested areas. No hardwood tree species are affected.

The adult beetle enters the tree through crevices in the bark and then creates S-shaped tunnels in the cambium tissue, just beneath the bark. This disrupts the flow of nutrients, killing the tree in typically 2-4 months. Most trees resist the initial attacks by secreting resin that can "pitch out" some adults and slow the entry of others, but trees almost always die as their defenses are overwhelmed by thousands of attacking beetles.

SPB is one of the most destructive pest of southern pine forests. From 1999-2002, an outbreak of the beetle in the southeastern U.S. resulted in more than one billion dollars in loss for the timber industry, according to the U.S. Forest Service. SPB populations naturally rise and fall. The beetle can persist for years at very low numbers, sometimes going unnoticed. At other times, however, the population can explode, rapidly killing pine trees across the landscape, as is currently occurring on Long Island. This switch between high and low population numbers is influenced by the availability of dense pine stands, the number of natural enemies, the types of fungus present, tree defenses, and changes in climate.

Confirmed SPB Locations in New York State

Infested trees in New York were first found in October, 2014 in Suffolk County on Long Island. The beetles most likely colonized Long Island from the New Jersey Pinelands.

SPB is widespread throughout Suffolk County, but the largest infestations are located in Wertheim National Wildlife Refuge, Connetquot River State Park, Hubbard County Park, and in East Quogue, NY.

Individual SPB has also been found in traps in Bear Mountain State Park in Orange and Rockland Counties, Schunnemunk State Park in Orange County, Roosa Gap State Forest in Sullivan County, Minnewaska State Park in Ulster County, and the Albany Pine Bush Preserve in Albany County. No infested trees have been found in these areas.

Signs Of An Infestation

a pine tree with popcorn-shaped clumps of resin scattered around the bark
In a SPB-infested pine, pitch
tubes are visible on the bark all
the way up the tree
a pine tree with tiny holes scattered across the bark
Exit holes created by adult beetles
  • Pitch tubes, or popcorn-shaped clumps of resin on the exterior of the bark all the way up the tree (not just the bottom 6 feet)
  • Tiny, scattered holes on the exterior of the bark
  • S-shaped tunnels under the bark
  • Pine trees that have recently died, characterized by reddish-brown needles

What You Can Do To Help

If you have dead pine trees, consider risk and liability. Remove standing dead trees if they have the potential to fall on people, structures, roads, or utility lines. Dead trees no longer have living SPB in them so they can be left standing if they do not pose a threat.

If you have living infested trees, surrounding uninfested trees are at risk. To keep SPB from spreading, remove and dispose of infested pines. Infested trees should not be cut and moved to new areas during the summer (when SPB are active) unless they will immediately be destroyed.

If you have uninfested trees, you may choose to protect them with preventive insecticides. Recommendations can be obtained by contacting Cornell Cooperative Extension of Suffolk County. Information for Homeowners (PDF) (article from Cornell Cooperative Extension of Suffolk County). You may also consider contacting a certified arborist for a consultation.

How to Report SPB

If you have found dead pine trees with infestation signs in New York State:

  1. Take photos of the infestation signs (include something for scale such as a coin). Photos are necessary to help us identify a SPB infestation.
  2. Note the location (intersecting roads, landmarks, or GPS coordinates).
  3. Submit a report using the free iMapInvasives app or their online system (leaves DEC website).
    1. If you do not have an iMap account, you may email photos to DEC at foresthealth@dec.ny.gov.
    2. You may choose to report by calling DEC's Forest Health Information Line at 1-866-640-0652 instead.

Ecosystems Most Affected by SPB

In New York, pitch pines have been attacked by SPB more than any other tree species. The majority of the pitch pines killed by SPB have been in the Long Island Central Pine Barrens, an ecosystem which contains a variety of habitats that support many rare and unique species. Although no infested trees have been located near the trap catches further north, rare communities in Minnewaska State Park and the Albany Pine Barrens Preserve, where pitch pine is also an important species, will be closely monitored.

Why SPB is More of a Problem on Long Island than in Southern Pine Forests

Pine Barren ecosystems are naturally adapted to and dependent on fire and are characterized by scattered pitch pine trees with dense shrub layers. In natural or properly managed conditions, fires increase the resiliency of pitch pines to SPB and other pests by naturally thinning tree stands which reduces the number and density of more competitive tree species such as oaks. Fires reduce competition between trees, making individual trees healthier. Smoke and thinning from fires also slow SPB infestations by disrupting the ability of beetles to communicate and organize infestations on trees using pheromones. In the southeastern United States, SPB is a natural part of pine stands and only becomes problematic when there is an absence of fire or other management to thin and maintain the pine stands, as is the case for the Long Island Central Pine Barrens.

Current Control Efforts in New York State

Eradication of this pest is not feasible because it has become widespread, moves quickly, and is present in neighboring states. As a result, forest health management conducted by the State is focused on protecting large forested blocks and unique habitats, such as the Core Preservation Area of the Long Island Central Pine Barrens Preserve. Management efforts include aerial and ground surveys, tree inventories, cutting infested trees, and thinning uninfested trees. So far, more than 10,000 trees have been cut in the Core Preservation Area in suppression efforts to slow the spread of SPB and protect surrounding trees.

Areas north of Long Island will continue to be monitored for early detection of SPB with traps, aerial surveys, and ground surveys. For more information, please refer to the SPB Management Plan (PDF), developed in partnership with experts from the U.S. Forest Service and academia.

DEC Management Reports

How Cutting Trees Helps Suppress Infestations

Infested pitch pine cut as part of winter suppression efforts
Infested pine cut as part of winter suppression efforts

The major focus of DEC efforts has been to suppress the infestation by cutting down infested trees using specific techniques during different seasons. Cutting infested trees in early winter can reduce the SPB population by killing the brood overwintering within the tree. Additional cuts made to the tree after it is on the ground causes the bark to loosen, exposing the overwintering beetles to cold temperatures and predators over time (see image).

During summer months when SPB is expanding, cutting infested trees disrupts the beetles' ability to communicate using pheromones making it more difficult for beetles to find each other and attack trees in large numbers. Cutting these trees also kills some of the brood within the tree as the beetle larvae are exposed to high temperatures from increased sun exposure, and predators.

Thinning uninfested trees is beneficial because increasing the distance between the trees disrupts the beetles' ability to communicate as they spread out more, searching for trees to attack. Thinning also accomplishes artificially what fire would have done naturally by reducing competition among trees creating a healthier stand that is better able to fend off attack by SPB and other pests. All types of trees and shrubs must be thinned in order to ensure every species, including the pines, have the best chance of regenerating. Without a diverse approach to thinning, pitch pines will be fighting an uphill battle against both attack by SPB and an overabundance of competing trees and shrubs.

untreated area showing 10 times larger infested area in 1 year
suppression cutting showed very little expansion in 1 year

No Funding Available for Tree Removal on Private Property

There are currently no state or federal funds available to provide financial assistance to private homeowners for the removal of individual trees attacked or killed by SPB. Private forest landowners may contact the Forest Stewardship Program which offers technical assistance to landowners. Woodland owners who have a forest stewardship plan may seek technical and financial assistance through the Environmental Quality Incentive Program.

Communities with municipal trees affected by SPB may apply for Urban and Community Forestry Grants and/or Southern Pine Beetle Community Recovery Grants.

Additional SPB Documents


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