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.   

Mole Crickets

Mole Crickets

A mole cricket has a face only a mother could love. They are so strange looking, in fact, that in the past week I’ve had two people ask me what they were. They have large, round, helmet-like heads, undersized eyes, and massive front claws used for digging. Unlike your garden-variety crickets, which really don’t cause any major damage to home landscapes, the mole cricket is quite the turfgrass menace. Instead of hopping about aboveground, they tunnel beneath the lawn and feast on the roots and leaves of grass, often destroying entire yards. They are also vegetable pests, going after tomatoes, cabbage, and peppers.

A young mole cricket. Its round head and large front claws distinguish it from other cricket species. Photo credit: Lucy Adams Stevenson
A) Horizontal and B) vertical view of a generalized tawny mole cricket burrow showing
1) horn, 2) 1st constriction, 3) bulb, 4) 2nd constriction, 5) turn-around,
6) surface tunnel, and 7) deep tunnel. Figure 1 from Nickerson et al. 1979. Ann. Entomol. Soc. Am. 72(3):438-440.

Mole crickets spend most of their time below ground and form burrows for hiding, laying eggs, and traversing through their territory. In mating season, males create a monotone song that averages 88 decibels—as loud as a motorcycle! The call comes from their burrows, which have funnel-like openings that expand at the surface, creating amplification comparable to a horn.

Beneficial larra wasp parasitizing a tawny mole cricket. Photo credit: UF IFAS

The tawny mole cricket (Neoscapteriscus vicinus) is the most common to our area and is an invasive species from South America. UF IFAS has had a specific research program related to mole cricket management since the late 1970’s. One successful outcome of this program has been the introduction of a biological control species, the larra wasp (Larra bicolor). The wasp manages mole cricket populations by stinging and temporarily paralyzing crickets. A female will then deposit an egg into the mole cricket’s body. The cricket recovers and goes about its daily routine until the egg hatches, at which point the larval wasp feeds on and eventually kills the mole cricket. Along with the wasp and release of flies and a nematode that also manage mole crickets, the biocontrol methods introduced between the 1980’s and 2004 have resulted in a 95% reduction in mole cricket populations in north Florida.

If you are seeing mole crickets, you can attract larra wasps to your property by planting shrubby false buttonweed or partridge pea plants, which the wasps feed on. If you have serious damage from mole crickets, check out this thorough Mole Cricket Integrated Pest Management Guide, or contact the horticulture agent at your local county extension office to get a site-specific recommendation for management.

Japanese beetle – Be Aware of the Potential Threat, Stay Informed.

Japanese beetle – Be Aware of the Potential Threat, Stay Informed.

Credit: Worrel Diedrick, Florida A&M University

They are known for their voracious feeding habits, targeting a wide range of plants, including ornamentals, fruit trees, and vegetables. I speak of no other than the Japanese beetle (Popillia japonica) an invasive species in the United States, originating from Japan.  

Though reports have been made of Japanese beetle sightings in Florida, there is still not a known established population. However, it’s important to note that the status of Japanese beetles in Florida can change, potentially rapidly, over time. Thus, it is important to be able to identify the species’ host plants and damaged caused. Early detection, monitoring, and swift action can help minimize the potential damage caused by invasive species like Japanese beetles that could potentially have negative impacts on agricultural crops, gardens, and ornamental plants.

Description

The adult Japanese beetle is an attractive pest that is generally metallic green, with bronze or copper-brown wing covers that do not completely cover the abdomen, revealing five patches of white hairs on each side and one pair on the last abdominal segment. These features distinguish Popillia japonica from all other similar looking beetles. In terms of shape, Japanese beetle generally have a broad oval body structure. Notably, the female beetles tend to be larger in size compared to their male counter parts.

Developmental stages usually take place under the soil after the female deposit her eggs. In most instances they complete their life cycle in one year emerging later in the summer months, however this varies based on locations.

Host plants

Japanese beetles have known to have over 300 host plant species; however, some common host plants include maples, soybean, ornamental apple species, plums, peaches, roses, blackberry, raspberry, limes, elms, grapes, and corn. Crepe myrtle and turfgrasses are also host plants.

Damages

Both adults and larvae cause plant damage. Adults feed on the foliage of host plants resulting in skeletonization of the leaves, while larvae feed on the root systems of turf and pasture species, affecting the ability of the plant to uptake nutrient and water from the soil.

Management

If Japanese beetle populations do become established in Florida, it is generally advisable to take measures to manage the population such as physically removing them, using pheromone traps, or other integrated pest management strategies. Chemical recommendations are not currently available in Florida since this beetle is not reported as a pest problem. However, it is always advisable to contact your Local Extension office for recommendations. The United States Department of Agriculture (USDA) has also provided some useful information on the Japanese beetle in their homeowner’s handbook titled “Managing the Japanese Beetle: A Homeowners Handbook’’.

For the most current and accurate information specific to Japanese beetles in Florida management and species identification, consult your extension office. Supporting document can also be found by clicking the link below.

Useful resources:

Plenty of Summer Gardening and Landscape Activities Ahead

Plenty of Summer Gardening and Landscape Activities Ahead

A watering tin and gardening gloves at a home garden.

Spending time gardening in the summer months can be difficult, especially in the Florida Panhandle. The brutally high temperatures and sometimes intensive humidity can make gardening seem unbearable. However, for those brave outdoor enthusiasts, there are always things to do around the homestead when it comes to vegetable gardening, landscape shrubs and lawn care.

Warm season vegetable gardening at this point becomes an uphill battle for some crops, with this being peak time for both insect and disease problems to occur. However, if you planted early enough, much of your harvest is probably in the safe zone. Scouting is key to prevent any major pest damage. Be sure to scout several times a week during these hot, summer days.

Shifting gears, the warm season is a good time to take extra special care of plants such as, azaleas and camellias, while they are establishing flower buds for the next bloom. A lack of water, fertilizer and pest detection and prevention can all certainly play a role in the following season’s flower production. Summer annuals always provide quick and easy color. Remember to feed established annuals with a complete fertilizer and remove faded blooms along the way. Water annuals well during hot, dry periods and control major annual pests to insure good production.

Finally, lawn maintenance is a need for many homeowners during this time of year. Almost all highly successful herbicides are no longer recommended at this point, as many will burn the turfgrass at temperatures above 80 degrees Fahrenheit. Depending on the weed pest and type of turfgrass, most likely the best way to control weeds in your lawn is to wait until cooler fall temperature to treat. Keeping good cultural practices this time of year will help in maintaining a healthy lawn and reduce pest pressure. Be sure to water lawns thoroughly when needed by applying one to three quarters of an inch of water weekly, depending on rainfall. Be sure to keep in mind mower height/frequency, as this is critical in keeping your lawn healthy. As stated in the “Mowing Your Florida Lawn” UF/IFAS EDIS publication, mow often enough so that no more than 1/3 of the blade height is removed per mowing. For example, if your St. Augustinegrass lawn is mowed at a height of 4 inches, it should be mowed before it grows to a height above 6 inches. It is important to always leave as much leaf surface as possible so that photosynthesis can occur, particularly in a grass that is subject to environmental or site stresses.

Unfortunately, it is chinch bug time again. Chinch bugs are prone to feed on St. Augustine lawns during hot, dry weather and may cause serious damage if not controlled. Damage usually occurs as a patch with a brown, dead center and yellowish margin. It seems chinch bugs get the blame, and often unjustly, for everything. Consult with your local county extension office to be sure the damage is not due to other reasons.

For more information, please contact your local county extension office.

Supporting information for this article can be found in the UF/IFAS EDIS publications/websites below:

Florida Vegetable Gardening Guide: https://edis.ifas.ufl.edu/publication/VH021

North Florida Gardening Calendar: https://edis.ifas.ufl.edu/publication/ep451#SECTION_7

Lawn Maintenance: https://edis.ifas.ufl.edu/entity/topic/lawn_care

Mowing Your Florida Lawn: https://edis.ifas.ufl.edu/publication/LH028

UF/IFAS Extension is an Equal Opportunity Institution.

Pest Management: An Integrated Approach

Pest Management: An Integrated Approach

Getting your landscape set up in the spring is an in-depth process.  Trees are pruned, soil amended, and the plantings have been accomplished.  Now you have exactly the look you want.  It would be easy to sit back, open a beverage of your choice, and watch it all come together.  Don’t get comfortable just yet, there is a group of pests eyeing your plants.  Insects come in many forms, looking to make a meal from your hard work.  Do not fear though, there is a straightforward way to protect yourself from these creatures.  Integrated pest management is a system of four control approaches designed to mitigate pest damage while minimizing impact on the environment.

Identification is Key

Before any of these steps may begin pests must be identified.  This starts with scouting your landscape via visual inspection.  Insects leave signs of their presence wherever they visit.  Be sure to inspect every part of your plants including the underside of leaves.  Here is where you will find insect eggs or frass (excrement) which are tell-tale signs of activity.  Once discovered, you need to identify your specific pest.  Insects are identified by their mouth parts when assessing plant damage.  Chewing insects remove leaf material (think caterpillars and grasshoppers).  Speckled leaves of brown and yellow is a symptom of piercing/sucking insects such as aphids.  Other times you may only find damage after the fact where black leaves turn out to be covered in sooty mold.  The sooty mold grows on the excreted honeydew of aphids, whiteflies.  Once identified, it is up to you to decide if the level of damage is worth it and how you would like to approach limiting the damage.

Sooty mold on ixora

Sooty mold on Ixora Photo Credits: UF/IFAS Kim Gabel

The First Three

The first strategy is cultural control wherein you optimize the environment in which your plant grows.  Improved drainage and removal of plants susceptible to insect attack are excellent examples.  You should also look into the lifecycle of insect pests to remove anything that will provide habitat.  The next control is mechanical.  This methodology is the most work intensive but comes with the least environmental impact as insects will be removed by hand.  Biological control is like mechanical control except that removal of the pest is left to natural predators.  There are many, but birds and lady beetles are best known.  Creating habitat for these will help keep insect populations to an acceptable level with the bonus of falling into Florida friendly landscaping philosophies.

Chemicals are Not the Bad Guy

Chemical control is the final approach.  Some may be surprised to find this here, but it is effective.  With the above in place, you may find there are still insect issues.  Chemicals will be your next step but do not feel put off by this approach.  Research the best products for your situation and follow the instructions on the label to the letter.  The label is designed to reduce risk to you and the environment while providing effective pest control.

Insect pests have plagued gardeners since the first person intentionally planted anything.  Controlling these pests using a multipronged approach is the optimal way to reduce damage to your plants while minimizing environmental impact.  Following the methodology in this post will bring a pest free landscape that you and your family will enjoy.  For more information on integrated pest management, see these Ask IFAS documents, or contact your local extension agent for additional information on this and any topic regarding your gardens and more.