Pine Bark Beetles – With Warming Weather Comes More Activity

Pine Bark Beetles – With Warming Weather Comes More Activity

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.

What is Crown Dieback in Trees?

What is Crown Dieback in Trees?

The crown of a tree is the leaf bearing twigs and branches and the spreading green foliage that we see. A heathy, full crown is a good indication of a healthy and vibrant tree. The crown and the foliage it supports is the energy collector and the center for photosynthesis, which is how the tree produces the energy it needs to live. For a tree to live and thrive, a full crown of leaves is essential, and an unhealthy and thin crown is an indicator the tree has issues. Crown dieback is often not noticed until it is relatively severe and at that point it can be too late. If a tree drops below a certain percentage of live crown it can no longer support itself and continues to decline. The good news is that if you notice your tree is starting to show signs of crown thinning and dieback you can likely intervene to improve its health or diagnose a problem early.

Tree Showing crown dieback, note the dead branches and lack of foliage on the outer branch tips.
Photo Credit-Ian Stone

Crown dieback, which is also referred to as crown decline, is a progressive issue that starts small and can progress to the point that only small sparse areas of foliage are left. It is a tree’s response to various stressors, including environmental conditions and severe rot/decay.  As a response to severe stress, the tree begins to abort part of the leaves and some of the small branch tips. If the stress continues to worsen, the tree will continue to abort more of the crown, producing progressively more dead wood. The tree is essentially trying to prune itself back to a manageable level of foliage based on the stress it is encountering. This can occur in both small, young trees and mature, established trees. A variety of conditions cause the stress that begins this process. For instance, you may notice crown dieback in young trees planted in compacted urban conditions such as parking lots and paved areas. Trees in these conditions experience stress from the compacted soil and encounter subsequent issues with water and nutrient stress. Large mature trees in an area that experienced recent construction may also exhibit dieback, especially if buffers and setbacks are not maintained or significant fill dirt is brought in. Issues from root disturbance and compaction cause stress and root dieback, which in turn causes visible crown dieback. Additionally, trees that are experiencing rot, decay, and other vascular disease issues will often begin to exhibit dieback. As the rot or vascular disease progresses, the tree is less able to transport water to the crown, which results in the crown dieback that can be seen as the crown thins. Often, in cases of rot, crown dieback will be the primary visible symptom that rot is occurring, as the rot can be concealed deep in the tree. While multiple stressors can be the cause of crown dieback, it is a clear indicator a tree is stressed and in trouble. If this condition goes unnoticed, it can progress past the point that the tree can be saved. However, if noticed and caught early, good tree care techniques can be applied that may restore the tree to heath. In cases of severe rot and decay, having the tree examined may prevent structural failure of a tree exhibiting crown dieback.

If you have a tree on your property that is exhibiting crown dieback, it is a good idea to have the tree examined by a professional to determine the extent and nature of the issue. Key signs of dieback are bare branch tips and dying foliage during spring and summer. It is natural to have some dead wood in a tree, but extensive dead wood around the entire perimeter of the crown is a cause of concern. With good diagnosis, the proper tree care techniques can be applied to help a tree recover. Waiting and hoping a tree with crown dieback will recover on its own is not a good course of action. Recognizing crown dieback and taking early action is the key to success. Contacting a Certified Arborist (www.treesaregood.org ) is a good step in getting an opinion on the extent of dieback, if the tree is recoverable, and how to best address the issue. You can also contact your local County Extension Office or Florida Forest Service County Forester for assistance.

What is Drilling Holes in My Trees?

What is Drilling Holes in My Trees?

They are often very prevalent on trees in our area; a strange string of shallow holes drilled in the bark of a tree. Often this is oozing sap, especially on pines and hardwoods with heavy sap flow, and more holes keep appearing as the sap dries up in others. I get calls and questions all the time about this strange phenomenon and what can be done about it. The calls are usually from homeowners with a prized backyard tree, but I get calls from farmers with orchard crops and other settings as well. What is causing this strange attack on these trees? What drills near perfect holes just into the sapwood of a tree? The answer is a bird of all things; and in particular the yellowbellied sapsucker (Sphyrapicus varius). This small to mid-sized bird is in the woodpecker family and has the peculiar diet of feeding on sweet and nourishing tree sap; as well as small insects attracted to and trapped into the sap. This little native bird drills and taps trees for sweet sap. Much like we humans do with maple trees up north for syrup production. They then visit their trees and drink the sap until the tap dries up and then drill another hole. This pattern of feeding leaves this banding of holes drilled on the tree, and they drill deep enough that it will be visible for quite a long time often permanently.

Yellowbellied Sapsucker damage on an American Sycamore-Walton County, FL Photo Credit: Ian Stone

The biggest question most people want answered, beside what is doing/causing this, is will this hurt the tree? The best answer to that is mostly no, but with all things tree related it depends. On young and smaller trees, particularly newly planted ones, the feeding can stress the tree and can cause some issues. The biggest risk is that if the sapsucker drills in a complete ring around the trunk, something more common on smaller trees, they could cause the tree to be girdled and killed. Another issue is that their feeding can attract pests and disease, such as bark and wood boring beetles along with some fungal infections of the open wounds. These pest and diseases may then go on to cause severe damage and death, especially if the tree is stressed by drought or other environmental factors. Ultimately, the feeding of the yellowbellied sapsucker rarely kills or severely damages trees by itself. Most of the time it just causes unsightly damage, and the bark damage and subsequent healing over can cause an unsightly area of bark. This is especially true on thin barked trees that have smooth bark, such as beech, magnolia, and birch.

You are probably wondering how to prevent this damage in the first place or stop it once a sapsucker takes a liking to your tree. The best thing to do is to make some changes in your landscape to prevent attracting sapsuckers and/or scare them away if they are in the area. Your first step is to learn to identify the yellowbellied sapsucker, so you can tell if they are in the area. Yellowbellied sapsuckers are a woodpecker and to many they look like several of our other small woodpeckers such as the downy, red-cockaded, and possibly even the red bellied. They look the most like a slightly larger downy woodpecker with more red on their heads. Males are the most brightly colored and have a read crown and throat patch, while females have the red crown only. The back and wings are black and white, and have somewhat of a ladder appearance on the back. They are smaller birds, around 7-8 in. in length, similar in size to a robin or cardinal. They cling to the bark and shuffle up and down the tree like other woodpeckers. The namesake yellow belly is faint and difficult to see at a distance without binoculars or other aids

Yellowbellied Sapsucker (Sphyrapicus varius) side profile Photo Credit:  Johnny N. Dell, Bugwood.org

If you notice yellowbellied sapsuckers in your area, you can watch them to see which trees they seem attracted to. Once you identify the portion of your yard they seem to like; you can put up windsocks or predatory statues to scare them away. This is the most effective method to keep these somewhat pesky birds out of an area and stop the tree damage. It also does not harm the birds or any other wildlife, though it may scare away birds that you would like to stick around. You may see some information about putting up hardware cloth or metal sheeting around the trunk of the tree. This is not a good method and often it does not stop the sapsuckers, who simply find another unguarded portion of the tree or work around the exclusion device. Using hardware cloth or sheeting can also damage the tree worse than the sapsucker’s feeding activity, and if not properly installed and consistently loosened they can even girdle and kill a tree. If you are having trouble with the interesting but pesky birds, use the scare away method consistently until they leave the area. If they believe predators are in the area and regularly startled while feeding they usually leave for a better feeding area pretty quickly.   

The Summer Stress is Starting to Show in Trees

The Summer Stress is Starting to Show in Trees

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.

This Heat Really Makes You Appreciate a Shade Tree

This Heat Really Makes You Appreciate a Shade Tree

If there is anything that is more refreshing than the cool shade of a tree on a hot August afternoon, I cannot quite think of it. Here on the Gulf Coast, the thought of the heat in the “Dog Days of Summer” conjures up images of the dogs lying by their owners’ rocking chairs on the veranda – shaded of course by the majestic live oaks out front. If you ever observe older homes in our region, they usually have large established shade trees to shade the house most of the day. In the days before air conditioning, I imagine a world without shade would be intolerable, nigh unlivable. If you have ever had to work on an asphalt parking lot or roof on a 100+ degree August day with no shade, you fully understand the term “heat island”. The steam rising off the same parking lot later after a passing shower or thunderstorm reinforces how hot that surface is.

Man walking a trail in Oak Hammock. UF/IFAS Photo: Thomas Wright.

These past few weeks the oppressive heat has made anything outside unbearable, especially in the heat of the afternoon. You can quickly understand why old farmers in our area worked from sunup to about 10 a.m. or so, then did lighter work in shaded areas or inside. They would go back out and work hard in the cool of the evening too, but you seldom saw anyone out in the open fields during the mid-day heat if it were avoidable. A shade tree in the pasture or up at the house was a welcomed oasis and favorite lunch spot. Going back in the air conditioning just caused you to have more trouble acclimating to the heat and could even cause medical problems if you we very hot and suddenly went into very cool air conditioning. I remember these summer patterns well growing up on the Gulf Coast, and still follow them when doing forestry field work. Being under a closed forest canopy was like being in air conditioning compared to the open sun of a logging deck or pasture. The shade of a tree or a forest canopy offered an amazing relief from the blazing August heat and humidity.

It is impossible to stress enough the importance of individual shade trees and tree cover to our urban areas. Imagine our towns and cities devoid of trees! Imagine Tallahassee without its canopy roads, themselves sort of an early cooling effort for travelers. Without these trees it would make these heat waves, as oppressive as they are already, downright scorching and close to unlivable. If you are doing any gardening or other outdoor activity during these hot days, it is highly likely you seek out a shady area to be in. As that shade moves with the sun through the day it is equally likely that you relocate and follow it as it moves. If you have a neighbor that has no tree cover and shade on their house, and you are on good and friendly terms, ask to compare power bills with them. Odds are their power bill is noticeably higher because they do not have the shade of trees. With all the important features our urban forest provides, we must realize that our trees and the urban forest they form are critical to our urban ecosystem we live in. Yes, I said urban ecosystem; we must remember that we are part of nature too and even though we have altered it to our needs, our urban environment is part of our ecosystem. Trees are the backbone of that here on the Gulf Coast and our cities show it. Gulf Coast cities generally have extensive tree cover, despite our disturbances from Hurricanes.

So, what do these shade trees and urban forests really do for us in terms of actual measurable data? We know from just walking under a tree on a 100+ degree day we can feel the difference but what does it equate to. A study published in the Journal of Forestry in 2018 found that an estimated 5.5 billion urban trees provided an estimated $5.4 billion in energy reduction alone (Nowak and Greenfield 2018). This same study found that Florida was the state with the highest annual urban forestry value with an estimated annual value of $1.9 billion. Those are some impressive numbers and help put the value of urban forests into some monetary terms, but this is just one study. Professionals studying urban forests and their benefits are constantly finding out more on just how valuable our urban tree cover is. A UF-IFAS EDIS publication in 2020 helped to further characterize our urban forests across the state. Urban areas in the Northern part of the state had the highest percentage of canopy cover, with our local Okaloosa-Fort Walton-Destin area being the highest at 74.4% (McLean et al. 2020). Our local Panhandle metropolitan areas all had high canopy cover in the 50% or higher range. That is good news for Panhandle urban areas as this tree cover helps improve quality of life in these areas.

The benefits provided by urban forest cover are not just confined to shade, cooling, and reduced energy use. We get other major benefits from our urban forest and tree cover. The same 2020 UF-IFAS study found that in Florida’s urban areas, trees remove 600,000 tons of air pollutants through their canopies, which results in $605 million in health care savings related to air pollution. Urban tree cover also prevents stormwater runoff into our waterbodies. The study found that Florida’s urban forest cover prevents 50 billion gallons of stormwater runoff, which results in a $451 million saving from avoided stormwater treatment. Those benefits would not be possible without our urban trees. Once you see the numbers, it is clear how our urban forest provides us with so many benefits we rarely see or consider.

When you walk under the shade of a tree or under a forest canopy on these scorching summer days you get an instant reminder of the benefit of that tree cover. The cool relief from the sun and heat is just one of the many benefits our trees and urban forests provide. Trees are one of our favorite parts of the landscape for many reasons and studies that quantify these benefits put in real term just how critical our urban forests are to us. Our tree cover helps clean our air and capture stormwater in our summer downpours.  As our communities grow and expand, we need to be sure to preserve the trees we have and plant new ones as the need arises. By keeping our urban forest cover intact, we can enjoy the cool shade and all the other benefits our urban trees provide.

References and further reading:

Nowak, David J; Greenfield, Eric J. 2018. US Urban Forest Statistics, Values, and Projections. Journal of Forestry. 116(2): 164-177.

McLean, Drew C., Andrew Koeser, Deborah R. Hilbert, Shawn Landry, Amr Abd-Elrahman, Katie Britt, Mary Lusk, Michael Andreu, and Robert Northrop. 2020. “Florida’s Urban Forest: A Valuation of Benefits: ENH1331/EP595, 11/2020”. EDIS 2020 (6). https://doi.org/10.32473/edis-ep595-2020. ENH1331/EP595: Florida’s Urban Forest: A Valuation of Benefits (ufl.edu)