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.
Description
Signs Of An Infestation
Though SPB is small, the signs of an infestation are noticeable and may appear and spread rapidly. Signs to look for include:
- 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 How SPB Damages Pine Trees
How SPB Damages Pine Trees
All hard pine trees are susceptible to an infestation of southern pine beetle, including pitch pine, red pine, and jack pine. In addition, SPB has been known to infest white pine, and other conifers when and infestation is very active and when the SPB population is extremely large. 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 infected trees almost always die as their defenses are overwhelmed by thousands of attacking beetles.
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.
- 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 climate change.
Look-alikes
SPB has several native look-alikes that also leave distinctive pitch tubes in pine trees.
SPB pitch tubes are:
- Popcorn-sized clumps of resin;
- Brownish-to white;
- Found on the exterior of the bark along the entire length of the tree;
- Located between bark cracks; and
- Accompanied by S-shaped larval galleries under the bark.
Pine Engraver Beetles (Ips sp.)
Pine engraver beetles belong to the genus of bark beetle, Ips, and infest a variety of pine and spruce trees. Although a close relative of southern pine beetle, they are mostly considered secondary pests infesting dead, dying, and stressed trees. Ips damage is often confused with a southern pine beetle infestation because Ips also make larval galleries, pitch tubes, and similar sized exit holes. These can be distinguished from one another by location on the tree, shape, size, and color.
Pine Engraver Beetle pitch tubes are:
- Located on bark plates;
- Orange to pink, and very small;
- Accompanied by "Y" or "H" shaped larval galleries under the bark, with small tunnels radiating away from the main chamber.
Black Turpentine Beetle (Dendroctonus terebrans)
The black turpentine beetle is another native insect that can be confused with SPB, but can be distinguished by the location and size of pitch tubes, as well as larval gallery shapes.
Black turpentine beetle pitch tubes:
- Are usually located at the bottom of the tree, under 12 feet;
- Are about twice the size of SPB's (about 1 inch in diameter) and often runny; and
- Have "D" or fan shaped larval galleries that are short and rarely cause much damage to their host.
Pitch Mass Borer (Synanthedon pini)
The pitch mass borer is a native species of moth that bores into spruce and pine throughout eastern North America. Although seldom encountered, they can cause their host tree to produce pitch tubes.
Pitch mass borer pitch tubes:
- Are usually very large and messy;
- Are located near broken branches and pruning scars; and
- Have fresh pitch tubes that contain small moth larvae, which can be extracted to confirm their identity.
Distribution and Habitats
In New York, trees infested with SPB 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 and throughout Long Island.
SPB has been found in traps in multiple locations in the Hudson Valley and in Saratoga County. Even though individual beetles have been caught at these locations, there are currently no signs on an infestation. In 2021, three infested trees were found and removed in Taconic State Park. It is expected that more infested trees will be found in other locations in New York State.
Impacts
SPB is one of the most destructive pests 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. 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.
SPB and Pine Barrens Ecosystem
The pine barrens ecosystem contains a variety of habitats that support many rare and unique species. It is a savannah-like landscape dominated by grasses and flowering plants with scattered clumps of trees and shrubs. It is fire-dependent and requires regular low-intensity forest fires to create and maintain a healthy ecosystem. 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 the competition for space, sunlight, water, and nutrients between trees, making individual trees healthier. Smoke and thinning from fires also slow SPB infestations by disrupting the ability of beetles to communicate and gather to form infestations.
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 forest. This is also the case for the Long Island Central Pine Barrens, where the lack of fire and management created the conditions for the SPB outbreak.
Management
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 DEC and partners 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;
- prescribed burns;
- cutting infested trees; and
- thinning uninfested 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.
Demonstration Forest at Rocky Point Pine Barrens State Forest
Southern pine beetle was found at Rocky Point Pine Barrens State Forest in Suffolk County in 2015. With support from the Environmental Protection Fund, DEC established a demonstration forest at this site to educate the public and conduct scientific research on fire as a management tool against SPB.
In spring of 2021, DEC and volunteers conducted the first prescribed burn at this site to improve the health of the forest.
How Cutting Trees Helps Suppress Infestations
The major focus of DEC's SPB management is to suppress infestations by cutting down infested trees. Trees are cut during the summer months, when SPB is spreading. Cutting infested trees:
- Creates greater distance between trees, which disrupts the beetles' ability to communicate using pheromones. This makes it more difficult for beetles to find each other and attack trees in large numbers.
- Kills some of the beetle larvae within the tree as they are exposed to high temperatures from increased sun exposure, and predators.
Thinning combined with the controlled burning maintain a healthy pine barren ecosystem that is more resilient to climate change and future insect attacks than an unmanaged forest.
DEC Management Reports
- 2020 Annual Report - NYS Southern Pine Beetle Response (PDF, 9.9 MB)
- 2019 Annual Report - NYS Southern Pine Beetle Response (PDF)
- Long Island Pine Barrens Restoration Update - 2019-2020 (PDF)
For older reports and updates, please email [email protected]
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 when they are available.
What You Can Do To Help
Removing Dead Trees that Pose a Safety Risk
Dead pine trees pose a safety risk. Remove standing dead trees if they have the potential to fall on people, structures, roads, or utility lines. However, dead trees no longer have living SPB in them so they can be left standing if they do not pose a safety risk..
Preventing the Spread of SPB to New Trees
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. 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:
- Take photos of the infestation signs (include something for scale such as a coin). Photos are necessary to help us identify a SPB infestation.
- Note the location (intersecting roads, landmarks, or GPS coordinates).
- Submit a report using the free iMapInvasives app or their online system.
-
- If you do not have an iMap account, you may email photos to DEC at [email protected].
- You may choose to report by calling DEC's Forest Health Information Line at 1-866-640-0652 instead.
