Pines are a familiar part of the Maryland landscape, growing in wooded stands and around homes where they provide year-round color, screening, and character.
But when a pine begins fading from green to yellow or brown, it’s important to take note. This kind of color change can suggest an active beetle infestation, which may be putting your pine tree at risk.
Making things even more challenging, there are several different beetle species that may attack our local pines, as southern pine beetles, Ips beetles, and black turpentine beetles are all found in Maryland.
We’ll explain how these three pine beetles differ, which Maryland pines may be at risk, the signs to watch for, and what you can do if you suspect an infestation.
Meet Maryland’s Pine Beetles: Southern Pine, Ips, and Black Turpentine
Southern pine, Ips, and black turpentine beetles all spend much of their lives beneath pine bark, where their feeding and tunneling can disrupt the movement of water and nutrients through the tree.
However, these beetles don’t all behave the same way. They tend to attack different parts of a pine, leave different signs behind, and vary in their ability to attack and spread among living trees. In some cases, several species may even colonize different portions of the same tree.
Knowing what to look for — and where to look — can provide important clues about which beetle may be attacking your pine.
Southern Pine Beetles Can Attack in Force
At only about 1/8 inch long, the southern pine beetle (Dendroctonus frontalis) proves that a forest pest doesn’t have to be large to cause serious damage.
These aggressive bark beetles can build populations capable of overwhelming living pines. They use chemical signals called aggregation pheromones to coordinate mass attacks, allowing large numbers of beetles to overcome a pine’s natural resin defenses.
Attacks typically begin along the middle and upper trunk. Look for small white to reddish pitch tubes, reddish boring dust, and eventually fading foliage. Beneath the bark, females create distinctive winding, S-shaped galleries where they lay their eggs.
Southern pine beetles also introduce blue-stain fungi that can interfere with the tree’s water-conducting tissues, adding to the damage caused by feeding and tunneling.
Once an attack succeeds, beetles can move into surrounding pines. During an outbreak, high southern pine beetle populations can spread through a stand rather than remaining confined to a single stressed tree.
Ips Beetles Take Advantage of Stressed Pines
Maryland is home to several species of Ips beetles, also known as pine engravers, including Ips avulsus, Ips grandicollis, and Ips calligraphus.
Depending on the species, adults range from about 1/8 to 1/4 inch long and can be distinguished by a hollowed-out rear lined with small toothlike spines.
Ips beetles are generally more opportunistic than southern pine beetles. They’re particularly attracted to pines that have been weakened or injured, as well as freshly cut or fallen wood that provides suitable material for breeding.
The three Ips species found in Maryland tend to attack different portions of the tree. Ips avulsus and Ips grandicollis tend to favor the upper portions of pines, while Ips calligraphus is more likely to attack farther down the trunk.
Black Turpentine Beetles Start Low
Reaching up to about 3/8 inch long, the black turpentine beetle (Dendroctonus terebrans) is considerably larger than some other pine beetles found in Maryland. It is also the predominant bark beetle in Western Maryland, making it especially relevant for homeowners in that area.
Like Ips beetles, black turpentine beetles tend to capitalize on stressed or injured pines. However, their attacks typically begin near the tree’s base and root collar.
One of the easiest signs to spot is a large white to reddish pitch tube near the base of the trunk, sometimes reaching roughly the size of a half dollar.
Black turpentine beetles may also colonize freshly cut pine stumps, which can provide breeding material for another generation. And these beetles don’t necessarily work alone: Black turpentine and southern pine beetles may sometimes colonize the same tree.
Why Pine Beetles Become a Problem in Maryland
Unlike invasive pests that arrived in Maryland from another part of the world, these bark beetles are native to North America. Southern pine beetle, for example, is native to Maryland, where outbreaks have been recorded since the 18th century.
Most of the time, bark beetles exist as part of the surrounding ecosystem without causing widespread tree loss.
But populations can grow and damage can increase when conditions work in their favor, particularly when pines are already stressed by drought, storms, flooding, construction damage, or other environmental pressures.
It’s important to note that different beetles often cause problems in different areas of our state.
The southern pine beetle has historically been most important in Southern Maryland and on the Eastern Shore, while Ips beetles are more common on the Western Shore and in Central Maryland. Black turpentine beetle is the predominant bark beetle in Western Maryland.
Which Pines Are at Risk in Maryland?
Any pine can become more vulnerable to bark beetles when it is stressed, but species, location, and tree condition all influence risk. In Maryland, the three beetles also show some differences in the pines they commonly attack.
- Loblolly Pine (Pinus taeda): Southern pine beetle is a particularly important pest of loblolly pine, especially in Southern Maryland and on the Eastern Shore. Dense stands and stressed trees can be particularly vulnerable when beetle populations rise.
- Eastern White Pine (Pinus strobus): White pine is an important host for Ips beetles in Central and Western Maryland. Trees weakened by drought, storm damage, construction, or other stress may be especially susceptible.
- Virginia Pine (Pinus virginiana): Virginia pine can be attacked by southern pine, Ips, and black turpentine beetles, making tree condition and the location of beetle activity particularly useful clues when identifying the culprit.
Tree condition often matters as much as species. Drought, root disturbance, storm damage, soil compaction, or construction injury can leave a pine more vulnerable to attack.
Signs and Symptoms of Beetle Infestation
A fading pine canopy may be what first catches your attention, but the most useful clues are often found on or beneath the bark.
Keep in mind that symptoms can overlap, and more than one beetle species may be present in the same tree. Still, the following signs can help narrow down the possibilities.
| What to Look For | Southern Pine Beetle | Ips Beetles | Black Turpentine Beetle |
| Typical Attack Location | Middle and upper trunk | Varies by species; upper branches to lower trunk | Lower trunk, root collar, and large roots |
| Pitch Tubes | Small, white to reddish | May be small or less noticeable, especially on stressed trees | Large, white to reddish; sometimes about the size of a half dollar |
| Boring Dust | Fine reddish dust in bark crevices and around the tree | Reddish or brown boring dust | Reddish-brown boring dust near the tree’s base |
| Gallery Pattern | Winding, S-shaped galleries | I-, H-, or Y-shaped galleries | Broad, irregular to fan-shaped galleries |
| Crown Changes | Needles fade from green to yellow, red, and eventually brown | Yellowing or browning foliage, often beginning in portions of the crown | Foliage may yellow and eventually turn reddish-brown as damage progresses |
| Don’t Rely on Crown Color Alone.
Yellow or brown needles can have many causes, and by the time an entire pine canopy has turned brown, a bark beetle infestation may already be advanced. Pitch tubes, boring dust, and galleries beneath the bark can provide much more specific evidence of what is happening. |
Can a Beetle-Infested Pine Recover?
Finding bark beetles on a pine does not always mean the tree is doomed.
When we evaluate an infested pine, the type of beetle and extent of the damage are two of the most important things we consider. Once beetles have successfully colonized much of a tree and the canopy is fading, there is often little that can be done to reverse the damage.
Southern pine beetle attacks can overwhelm a tree quickly, particularly when large numbers of beetles attack together. Likewise, there is no effective treatment for saving an individual pine once it has been successfully colonized by Ips beetles. In these cases, management often shifts from saving the infested tree to reducing the risk to nearby pines.
Black turpentine beetle offers a little more room for optimism. A pine may survive a light infestation, particularly when attacks are limited and the tree remains otherwise vigorous. Heavy attacks, continued decline, or widespread crown discoloration make recovery less likely.
| Treatment Can’t Undo Existing Beetle Damage
Spraying an already infested pine generally cannot reach beetles protected beneath the bark or repair tissues they have already damaged. Preventive insecticides may sometimes be used to protect healthy, high-value pines from future attacks, but treatment decisions should depend on the beetle involved, the tree’s condition, and the level of risk. |
What to Do If You Suspect Beetles Are Attacking Your Pines
If you find pitch tubes, boring dust, fading needles, or other signs of bark beetles, it’s important to get professional help from an ISA-certified arborist.
Your arborist will start by determining what is actually attacking the tree and how far the damage has progressed. From there, they can recommend an appropriate treatment, depending on the beetle(s) involved, the condition of the pine, and whether nearby trees may also be at risk.
- Confirm the Cause: Bark beetle symptoms can resemble other tree problems, and several beetle species may even attack the same pine. Our team can help identify the beetle, assess the extent of the damage, and determine whether the tree has a realistic chance of recovery.
- Reduce Stress on Nearby Pines: Healthy trees are generally better able to defend themselves against bark beetles. During dry periods, adequate watering and avoiding additional root, trunk, or soil disturbance can help.
- Remove Dead or Dying Trees When Appropriate: Severely infested trees may need to be removed, both for safety and because dead or dying pine material can provide breeding sites for additional beetles.
- Manage Cut Pine Material Carefully: Freshly cut pine, fallen trees, and stumps can attract Ips and black turpentine beetles. Promptly managing this material can reduce potential breeding sites around healthy pines.
Frequently Asked Questions About Pine Bark Beetles in Maryland
Pine bark beetles can pose a serious threat to Maryland’s pines, which leaves homeowners with a number of questions. Here are a few of the most common ones local homeowners may have.
Are pine bark beetles native to Maryland?
Yes. Southern pine, Ips, and black turpentine beetles are all bark beetles found in Maryland, although their prevalence varies by region and conditions.
Can pine bark beetles kill a healthy tree?
Southern pine beetles can overwhelm healthy pines when populations are high. Ips and black turpentine beetles are more commonly associated with trees already weakened by drought, injury, storms, or other stress.
How can I tell which pine beetle is attacking my tree?
Attack location provides an important clue. Southern pine beetles typically begin along the middle or upper trunk, Ips attack locations vary by species, and black turpentine beetles usually attack near the tree’s base.
Will pine bark beetles spread to nearby trees?
They can. Southern pine beetle infestations in particular can spread rapidly to surrounding pines when populations are high, while fresh or stressed pine material may attract Ips and black turpentine beetles.
Should I remove a pine that has bark beetles?
Not automatically. Whether removal is appropriate depends on the beetle involved, the extent of damage, the tree’s condition, and any safety risk it presents.
Can I spray an infested pine to kill the beetles?
Spraying the outside of an already infested tree generally cannot reach beetles protected beneath the bark or reverse existing damage. Preventive treatments may sometimes be appropriate for healthy, high-value pines at risk of attack.
Can Baker Tree Services treat pine bark beetles?
Baker Tree Services can assess affected pines, help identify signs of bark beetle activity, and recommend appropriate tree-care or removal options, including preventive sprays when appropriate.
Get Expert Help With Pine Beetles in Maryland
If you’ve noticed pitch tubes, boring dust, fading needles, or other signs of bark beetle activity, identifying the culprit is the first step toward deciding what to do next. An infested pine may need treatment, monitoring, or removal depending on the beetle involved and how far the damage has progressed.
Baker Tree Services’ ISA-certified arborists can evaluate your pine, look for signs of southern pine, Ips, or black turpentine beetles, and recommend an appropriate course of action.
Contact Baker Tree Services to schedule an evaluation, and we’ll help you determine the right next step for your pine and the surrounding trees.
Sources & References
- University of Maryland Extension – “Conifer Bark Beetles on Trees and Shrubs”
Used for Maryland-specific identification and distribution of southern pine, Ips, and black turpentine beetles; the three Ips species found in Maryland and their typical attack locations.
https://extension.umd.edu/resource/conifer-bark-beetles-trees-and-shrubs - University of Maryland Extension – “Forest Pests: Southern Pine Beetle (Dendroctonus frontalis)”
Used for the southern pine beetle’s native status in Maryland, its history of outbreaks dating to the 18th century, its importance as a destructive pine pest, and the periodic nature of outbreaks. Also supports Maryland-specific discussion of southern pine beetle risk and management.
https://extension.umd.edu/resource/forest-pests-southern-pine-beetle-dendroctonus-frontalis - University of Maryland Extension / Maryland Department of Natural Resources – “Southern Pine Beetle in Maryland”
Used for southern pine beetle distribution on Maryland’s Eastern Shore and in Southern Maryland; the role of lightning, site disturbance, physical injury, and other tree stress in triggering attacks; the potential for high beetle populations to spread rapidly to surrounding pines; and the importance of maintaining healthy, vigorous trees.
https://extension.umd.edu/sites/extension.umd.edu/files/2022-08/2016_vol24_no4.pdf - U.S. Forest Service – “Southern Pine Bark Beetle Guild”
Used for comparisons among southern pine beetle, black turpentine beetle, and the three Ips species covered in the article; their tendency to share the same pine host; differences in host-tree location and gallery patterns; preference for trees under varying degrees of stress; and the chemical and other cues these beetles use to locate and colonize hosts.
https://research.fs.usda.gov/treesearch/39042 - University of Florida IFAS Extension – “Black Turpentine Beetle, Dendroctonus terebrans (Olivier) (Insecta: Coleoptera: Curculionidae: Scolytinae)”
Used for black turpentine beetle size and identification; its preference for stressed or injured pines, fresh stumps, lower trunks, and large roots.
https://ask.ifas.ufl.edu/publication/IN636