Pine Bark Beetles are an ever-present issue in both the urban and rural landscape across the Panhandle. If you have pines in your landscape you very well may experience issues with pine bark beetles. The tiny insects can decimate a pine rather quickly, and there are more than one type that can infest a tree. The Southern Pine Beetle is the bark beetle that most people are familiar with and most concerned about. In forestry settings the Southern Pine Beetle can have epidemic outbreaks that can devastate large areas of pine forests and plantation. While the Southern Pine Beetle is very destructive and a concern to forest health, there are other common pine bark beetles that often attack trees in our area. The two other common bark beetles are Ips pine engraver beetles and Black Turpentine Beetles. In urban settings these two beetles often are more common but they can easily wipe out several trees or more, which may pose a significant issue in the landscape.
Resin pitches on bark that indicate pine bark beetle infestation. This shows a pine that is actively colonized by bark beetles and should be removed. Photo Credit-Ian Stone
There are multiple species of Ips beetles and these tend to be a significant issue in landscapes, because they can easily wipe out most of the trees in a yard or park. They almost always target stressed or damaged trees, but they usually do not wipe out large areas like Southern Pine Beetle. Different Ips species will often attack different portions of the tree which can result in partial dieback of the crown or a slow yellowing and browning of the foliage. These beetles are very small, smaller than a grain of rice, and often are not seen readily without close inspection. Like other bark beetles the bark will often have resin oozing out and forming small pockets resembling popcorn. Other signs include yellowing and browning foliage and an accumulation of sawdust like material around the base. You may also see exit holes in the bark about the size of a pencil lead.
The Black Turpentine Beetle is closely related to the Southern Pine Beetle, but much larger and often attacks the lower portion of the tree. These beetles commonly attack older, damaged, and weakened trees. Historically they were often associated with turpentining operations and trees that had been worked for resin production, hence their common name. They are very attracted to trees that are damaged by equipment or that have had construction occur around them recently. The symptoms are generally the same as other pine bark beetles, but the resin pitches are larger and the exit holes are about the size of an eraser. While they are larger than other bark beetle they are still quite small by comparison to other insects, not much larger than a grain of rice and somewhat smaller than a pea.
If you notice pines in your area with bark beetle symptoms it is natural to be concerned. As the weather warms bark beetle activity increases and you may notice these symptoms on your pines. If you had bark beetles attack a tree in your yard last year you will want to keep an eye out for other pines being attacked in the spring. With the drought last year bark beetle activity increased and if the infected trees were not removed spots may reactivate in the spring and summer. Unfortunately, once bark beetles attack a pine there is really nothing to do other than removal. Insecticides and sprays will not do anything against bark beetles that are already in the tree. If you have high value pines in your landscape you want to preserve, prevention is key. First and foremost avoiding issues from equipment damage and construction is key as this will attract beetles. Preventative injections with systemic insecticides by a licensed professional can protect trees in your landscape. If you have noticed bark beetle activity in the area or have had to recently remove trees that died from bark beetles, consider preventative treatment to preserve trees that are at risk. Otherwise removing trees that become infested with bark beetles promptly is the best solution. Sometimes it can be difficult to determine what trees to remove, but any trees showing active bark beetle activity should be removed to prevent spread. Once bark beetles have colonized a tree and it is in decline preventative insecticide treatments are not going to be effective. You also don’t need to remove every pine in your landscape just because a single tree has bark beetles. At the following link you will find an IFAS EDIS article that is helpful in identifying bark beetles and making a decision about an infected tree https://edis.ifas.ufl.edu/publication/FR399.
If you see bark beetle activity on your property this spring contact your local IFAS extension office or your Florida Forest Service County Forester’s office for assistance and information. A Certified Arborist can assist you with determining how to remove infected trees or apply preventative treatments to trees at risk. With good decision making and management pine bark beetle attacks can be managed before they grow and spread. Now is a good time to keep an eye out and get ahead of any infestations that start.
They’ve mostly all moved away for now, but every winter and early spring the office gets questions about tiny beetles in homes. These beetles are small with spotty color patterns. The answer is carpet beetles. Carpet may be in their name, but it may not be their favorite spot. Carpet beetles feed on a lot of the same things as clothes moths such as wool, felt, and fur because these materials contain keratin. And their feeding damage is often mistaken for that of clothes moths.
Varied carpet beetle adult. Photo Credit: Lyle J. Buss, University of Florida/IFAS
Adult carpet beetles are between 1/16 to 1/8-inch in length. They are oval-shaped and range in color from black to various patterns of white, brown, yellow, and orange. The majority of samples we see are black and white mottled. The adults are often found on windowsills and window stools in the springtime. The larvae conduct all the damage to fabrics and other materials, while the adults stick to feeding on flower pollen. The evidence of feeding can be seen by threadbare spots and irregular holes. Blankets and clothes in storage and carpeted areas under furniture are preferred because they are undisturbed.
As with most insect pests, prevention is the best control for carpet beetles. In addition to feeding on fabrics and material, larvae feed on dust, lint, and animal hair. Frequent cleaning of floors and vacuuming of rugs and carpets eliminates most of the food supply. Stored blankets, clothes, and rugs should be periodically cleaned, brushed, and or sunned. Moth balls can be used at labeled rates but should not be the sole means of control.
Not all fall color is a good thing. This statement is especially true when it comes to twig pruners and twig girdlers. These two species of longhorned beetles can certainly disappoint your grand expectations of a beautiful array of fall color. Both species cause the tips of twigs to fall to the ground in late summer, sometimes leaving your trees in an undesirable form.
Twig Pruners
The twig pruner (Elaphidionoides villosus or Anelaphus villosus) is a small longhorned beetle that attacks numerous species of hardwoods. It is usually classified as a secondary pest of declining trees and shrubs. Female twig pruners lay their eggs in late spring at the leaf axils. When the eggs hatch, the grubs bore into twigs and continue to bore as they mature. The larvae then chew concentric rings just underneath the bark. The infested twigs and branches eventually drop to the ground with the larvae inside. The larvae pupate inside the fallen twig throughout the winter.
An adult twig pruner. Photo Credit: University of Georgia
Twig Girdlers
The twig girdler (Oncideres cingulata) is a small longhorned beetle that invades many species of hardwoods. Female twig girdlers lay their eggs in late summer in small twigs (about 3/8 inch diameter) that are covered with a thin layer of bark. The female chews a concentric ring around the outside of the twig, causing the end of the twig to die. The female chews a small notch in the dead twig and lays her eggs. After the eggs hatch, the larvae feed on the dead twigs and develop into adults before chewing their way out. The adults fly away to new host trees.
An adult twig girdler. Photo Credit: Lacy L. Hyche, Auburn University
Management and Control
It’s important to plant the right plant in the right place. Healthy trees and shrubs are the best defense against insect pests. Twig pruners and twig girdlers live in dying or dead twigs and branches. If you have trees that have suffered damage from these pests you will notice an abundance of fallen twig ends around the base of your trees. Rake and remove fallen twigs from around the trees and destroy or dispose them. This will help reduce pruner and girdler numbers in subsequent years.
It has been a hard summer climate wise and as we go into fall it is nice to start getting some relief from the heat. As the heat tones down, we are still facing a drought, which is not as severe as areas to our west but is still significant across much of the Panhandle. In our tree cover, the stress from the harsh summer this year is starting to show. You can see it in trees around the area, and it particularly seems to affect certain trees and conditions more than others. Where you are starting to see it most is in our ever-present pines, which make up the majority of our forest and tree cover in our region. If you keep a look out you may notice some pines in the areas with yellowing or brown needles or that are losing their needles. Those are clear signs of a possible bark beetle attack, which is a common issue when pines are stressed or damaged. Trees planted in the last year that are not yet fully established often show stress in a hot dry summer like this year. Even older and well-established trees in areas are showing some signs of stress from the hot dry conditions we have had this summer. Some trees are less adapted to dryer areas and when planted off site can experience more stress in dry conditions. If you look around across the Panhandle right now you can see clear signs of stress in some trees. It becomes more evident in late summer and early fall as the accumulated stressors of summer push trees into physiological conditions that cause stress responses. The big question is what to do if you notice a landscape tree that is exhibiting signs of stress, particularly drought stress.
Pine damaged by construction equipment. Barking injuries like this can encourage bark beetle attacks. Photo Credit: Ian Stone
For pines the issue is likely to be bark beetles, of which there are several types. All pine bark beetles are native to our area and the degree of damage they do varies by species and conditions. The issue with stressed trees is that most bark beetles attack those trees. When a hot dry summer occurs bark beetle activity increases as the stressed trees become less able to fend off attacks by these beetles. Unfortunately, when bark beetles attack a pine in an area the best answer is prompt removal and disposal of the infected tree material. To protect high value trees in an area where bark beetles are active there are some injection pesticides that can prevent infestation, but once a tree has been infested and begun to show symptoms little can be done to bring it back. When bark beetles attack a stressed pine, most are effectively finishing off a tree that may have died regardless. The key is to prevent them from spreading to other pines in the area or attracting them to a stressed tree in an area. With trees already stressed in our area the big prevention option is not to damage or stress any pines already on the landscape. Most pine bark beetles are attracted to trees by chemicals in pitch and resin given off by wounds or damage. Often the stress from new landscaping projects or construction around pines can cause several to succumb to bark beetles. Your best prevention is to keep equipment well away from the tree and avoid damaging or injuring the tree, especially scraping areas of bark off. Larger and older trees can be vulnerable, as well as overcrowded trees that are too dense or overtopped by others. As the cooler weather approaches bark beetle activity should decrease along with the risk of losing a pine to these pests.
Recently constructed sidewalk. Construction activities extended well into the root zone of the tree, which can cause stress and damage. Photo Credit; Ian Stone
For other trees there are additional precautions that can be taken to lessen the potential that a tree will succumb to drought and other stress. Newly planted trees or those established in the last several years are particularly at risk and should be watered regularly during this dry period. Until rains return, a good method of slowly applying water deeply to the root zone is best. Properly applied mulch can help keep the soil cooler and moist around a newly planted tree. Drip irrigation, soaker hoses, and similar methods are best, and a method that specifically applies water slowly to the tree’s root zone gives the best results. Watering your lawn does not supply sufficient water to landscape trees, especially in drought conditions. Lawn irrigation is designed to apply irrigation needed to the top portion of the soil that is available to the grass. Trees have completely different requirements and need different watering methods and amounts. If you don’t have dedicated irrigation available and you have a tree that needs water, you can use irrigation donuts or bags. These are often a good solution for a tree that needs watering temporarily. Once a tree is well established it usually can withstand even severe drought, but during the establishment phase paying attention to water needs is critical in a summer drought like we have had.
Large established trees are also not immune from the heat and dry conditions that have plagued the Panhandle this summer. Usually when conditions change these trees recover but may abort some branches or exhibit some leaf drop while stressed. Leaf drop is a phenomenon that can occur when deciduous trees are stressed. It is a method of conserving water needs by reducing the leaf demand. Usually, the tree will recover and leaf out again fine next year. A tree may abort some branches or have some branch tips die back to make it through a rough period. Trees that are overcrowded, overtopped, or have other issues are the most at risk from environmental stress. This is why good tree selection along with proper tree care and maintenance is essential. When a hot dry summer like we have had comes along well cared for and maintained trees do best. Trees that prefer more moisture like bald cypress, red maple, sycamore, and some oaks can be planted in dryer sites, but when a severe drought comes along they often don’t have the ability to handle the moisture stress that trees adapted to dryer sites can. This is why site selection is so important, it is when we have extreme conditions that off site plantings typically suffer the worst and those can be larger more established trees.
With the cool weather hopefully we will get a reprieve and some rain soon. Given that fall is one of our dryer periods it may be likely that drought conditions could persist until early winter. Good care and tree maintenance is essential to getting your trees through stressful periods like this summer. For younger trees watering and care is essential while they get established. For older established trees avoid doing any construction or other disturbing activities around them until conditions improve. If you have trees that are exhibiting signs of decline or pest attacks call your local extension office or Florida Forest Service County Forester office. With any luck, colder weather with winter rains will be here soon and trees in our area will recover over the dormant period.
Winter Storm Elliott brought freezing temperatures to the Panhandle on December 24th that lasted through December 28th, 2022. While we’ve seen freezing temperatures in years past, none remained below freezing for as long as Winter Storm Elliott did, resulting in significant injury to citrus in our region. Those trees that received significant freeze damage are more vulnerable to pests and diseases. One such pest we are seeing as a result of Winter Storm Elliott, are ambrosia beetles.
Granulate Ambrosia Beetle, Xylosandrus crassiusculus Photo credit: David Almquist.
Ambrosia beetles are a group of wood-boring insects that live in dead or severely stressed trees or dead wood. They are attracted to the odor that the dead/dying trees give off, which is why you may be seeing them now in freeze damaged citrus trees. Once they locate a sick tree, they bore into the lower part of the tree (about 2-3 feet from the ground), creating a tunnel or a gallery. You’ll likely notice sawdust from the galleries at the base of the tree or you may notice a toothpick like protrusion of sawdust at the base of the gallery.
Toothpick like protrusions from ambrosia beetles. Photo credit: Danielle Williams.
Several species of ambrosia beetles are considered true pests that attack living trees, but most species are secondary to another issue. Because ambrosia beetles generally prefer dead or dying trees, they are not typically a problem for citrus trees. If you are seeing signs of ambrosia beetles on your trees, the beetles are likely targeting trees that sustained major freeze damage from Winter Storm Elliott.
Unfortunately, there are no effective strategies to control ambrosia beetles once they attack a tree, so the best line of defense is to keep your trees healthy. Consider the first three UF/IFAS Florida-Friendly Landscape principles for maintaining tree health:
#1 Right Plant, Right Place: Select plants that match the site’s soil, light, water, and climatic conditions. Plants that are well adapted for our region will be lower maintenance and have a better chance of flourishing as opposed to those that aren’t. For information on citrus varieties adapted for our region, please visit: UF/IFAS Evaluating Cold-Hardy Citrus Varieties for the Panhandle | Panhandle Agriculture (ufl.edu)
#2 Water Efficiently and #3 Fertilize Appropriately: Proper irrigation and fertilization enhances plant growth. Over watering or over fertilizing can do more harm than good so it is best to follow UF/IFAS recommendation rates and application timing.
