by Larry Williams | Nov 6, 2017
Saddleback Caterpillar. Image Credit: Matthew Orwat UF / IFAS
Did you know we have caterpillars that sting here in Northwest Florida? Well, we do and you’d be wise to learn about them and how to recognize them.
These caterpillars do not sting in the same way that a wasp or bee might sting. They do not have “stingers.” But they do have spines, also called nettling hairs, which are connected to poison glands that can inflict a painful reaction if touched.
The four nettling caterpillars that you are more likely to encounter in Florida are the hag caterpillar, Io moth caterpillar, puss caterpillar and saddleback caterpillar. Those that you are less likely to come in contact with include the buck moth caterpillar, flannel moth caterpillar, spiny oak-slug caterpillar and tussock moth caterpillar.
The “sting” is unintentional, not deliberate. When brushed against or touched, the toxin-bearing spines break off, releasing toxins. In some cases, broken spines pierce the skin. In other cases, toxins leak out onto the surface of the skin.
A University of Florida-IFAS Extension publication about these caterpillars states, “Some people experience severe reactions to the poison released by the spines and require medical attention. Others experience only an itching or burning sensation.”
The kind of reaction can depend on the type of caterpillar, extent of contact and susceptibility of individual. Fortunately, most of these caterpillars spend most of their time high up in trees away from us. But they can blow out of the trees during windy weather or come down still attached to branches and limbs that fall.
The saddleback caterpillar is more likely to be encountered because it feeds on many of our common landscape plants such as hibiscus and palms. But it is also known to feed on azaleas, fruit trees and even canna lilies. The saddleback caterpillar is striking in appearance with what looks like a bright green “blanket” draped over its back and a brown saddle-shaped oval area in the center of the blanket. Its spines are colorful, sharp and protrude from the front, back and sides of the caterpillar. It is stout and 1 to 1.5 inches long.
I’ve received questions about the puss caterpillar recently from people who have encountered it. This caterpillar is stout-bodied, almost 1 inch long and completely covered with gray to brown soft hairs. They seem to prefer leaves of oaks and citrus but they will feed on a variety of broadleaf trees and shrubs,
Because of their bright colors and interesting appearance, children may be tempted to touch or pick up some of these stinging caterpillars.
More information on these caterpillars is available at these websites:
http://edis.ifas.ufl.edu/pdffiles/IN/IN01400.pdf
http://www.poisoncentertampa.org/poison-topics/venomous-critters/caterpillars
by Beth Bolles | Oct 23, 2017
Trees are a landscape asset for many homeowners. When a new tree is installed in our landscapes, we can’t wait for it to mature to provide shade or landscape interest. The heartbreak for many homeowners comes when this important part of their landscape, begins to decline five to ten years after establishment. We often consider a pest as the cause. The common culprit is often hidden below the mulch and soil and is easily preventable.
When larger specimen trees are installed in residential and commercial landscapes, they may be delivered with materials that help hold the rootball in place. Strapping often runs over the rootball and when trees are young is several inches away from the trunk. Installers or homeowners often do not cut the strapping during installation.
As this tree continue to grow, the rootball straps will interfere with normal trunk development. Cutting the straps takes only a few seconds at the time of planting. Photo by Beth Bolles, UF / IFAS Extension Escambia County
Over the years, tree trunks will grow in diameter and eventually reach the strapping. Because the strapping is still firmly in place, it can cut into a growing tree, resulting in girdling. Although many trees try to overcome the injured area by forming new wood over and around the girdling, this is a major stress that interferes with water and food movement in the plant. What we see is a tree that may be slower to leaf out in the spring, a thinning canopy, and twig dieback. These symptoms may be confused with another cause since the strapping is normally hidden from view.
The crape myrtle on the right has a very thin canopy. Investigation found a severe area of girdling from strapping left uncut at planting. Photo by Beth Bolles, UF / IFAS Extension Escambia County.
If you do have a tree that exhibits the above listed symptoms, it never hurts to look at the trunk and root flare just below the mulch and soil surface. If you find strapping still in place, cut it so that it is loose. Depending on the severity of the problem, this may not save the tree but it is worth a try on your important investment.
by Beth Bolles | Sep 8, 2017
Trees are a valuable resource. They add beauty to our community, serve as food and shelter for animals, filter the air, and cool urban environments. Trees can also be a liability when poorly maintained, damaged, or diseased. There are often times when an arborist is needed to help determine the best course of action for the tree.
There are many individuals who are involved in the tree care and removal business. Not all of these people are certified in the care of trees. Arborists are people who receiving training in the planting, care, and maintenance of trees.
Professional arborists have specialized training to create safe, structurally sound trees, even when damaged by storms. Photo by Beth Bolles, UF IFAS Extension Escambia County
Certified arborists go through a voluntary certification process with the International Society of Arboriculture which means that they have at least three years experience and have passed a comprehensive examination developed by tree experts. A certified arborist maintains certification by attending regular training courses.
An arborist may also be a member of another organization which helps professionals stay up-to-date on tree care techniques and information. These include the National Arborist Association and the American Society of Consulting Arborists.
Hiring an arborist to work on your trees is important for several reasons. An arborist can evaluate the tree and determine the steps necessary to create a healthy specimen. In regards to pruning, the professional will determine what type of pruning is necessary and remove branches properly.
Professionals will also perform tree care practices that are recommended by University research. A few practices that the arborist would not perform include topping trees, using climbing spikes on trees which are not being removed, and making flush cuts against the trunk.
Flush cuts are damaging to trees and can create a future hazard in your landscape. Photo by Beth Bolles, UF IFAS Extension Escambia County
Finally arborists have the skills and equipment to safely and efficiently prune or remove trees. This includes personal and property damage insurance and workers compensation insurance.
Next time you need tree work or advice, hire a professional for the job. It will definitely be worth the investment.
by Sheila Dunning | May 25, 2017
As oak trees are now fully leafing out and people start hanging out in the shade of the canopy, many of you are noticing strange growths on the branches. They look like potatoes, spiky cones and fuzz balls on the leaves and stems. Don’t worry. It’s just a harmless wasp that chose that tree to create a nursery for her young.
Galls are abnormal plant growth or swellings comprised of plant tissue. Galls are usually found on foliage or twigs. These unusual deformities are caused by plant growth-regulating chemicals produced by tiny wasps. The chemicals produced by these insects interfere with normal plant cell growth.
The life cycles of the various gall-forming wasps are highly variable. Two or more years are required for gall wasps that develop in woody twig galls to reach maturity. Gall-forming wasps usually overwinter as adults in protected places away from the host tree. As the buds break in the spring and the leaves begin to expand, these small wasps start to lay their eggs in expanding plant tissue. During the egg-laying process or early larval-feeding period, specialized body glands secrete growth-regulating chemicals that interact with certain plant chemicals to produce these abnormal growths.
After a brief period of cell growth, gall development stops completely. Once these galls are formed, they do not continue to use nutrients from the host plant. The insect is confined within “its house” and feeds only on gall tissue during the remainder of its development. The galls provide shelter, protection, and food for the immature wasps. Inside a gall, the larvae are surrounded by tissues rich in nutrients
There are a variety of gall-forming species of small wasps that commonly infest oak, Quercus spp ., trees. Galls generally are aesthetically objectionable to homeowners who find them unattractive and fear that galls will cause damage to the health of their oak trees. Most leaf galls on oak cause little or no harm to the health of a tree. However, twig or branch galls may cause injury by distorting branch development in a heavily infested tree.
Chemical control is seldom suggested for management of leaf galls on oak. Cultural methods of control may be effective in reducing the impact of these insects. Some fallen leaves may harbor various life stages of gall-producing pests. Therefore, it may be useful to collect and destroy all infested leaves. Some of these pests overwinter in twigs and branches of oak. Where such woody galls are detected, prune and destroy the infested plant material when the galls are small and have just started to develop. But, remember every bug needs a home!
All photos by Eileen Buss, UF Entomologist
by Julie McConnell | Apr 7, 2017
It’s really tempting to buy a tree and plant it in the middle of your lawn or directly in front of your picture window, but instead take some time to choose the best spot first. Several considerations such as maintenance and mature size should be taken into account before the site is selected.
Mowing close to the trunk of this Pindo palm has caused repeated injury to the trunk. Photo: JMcConnell, UF/IFAS
Placing a tree in a lawn area without creating a bed can lead to maintenance issues for both the tree and the turfgrass. It is easy to simply cut out a small patch of turf the size of the rootball and install a tree, however, as the grass grows up towards the trunk over time maintaining that grass will become difficult. It is common to see mechanical injuries to tree trunks because weed eaters or mowers have chipped away at the bark when trying to cut the grass. Other potential problems are irrigation zones calibrated for turf delivering the wrong amount of water to trees and herbicides used on grass that may cause injury to trees.
Over time, as the tree canopy grows, it will create shade and any grass trying to grow in that area will thin and be more susceptible to disease and insect pressure. By creating a large ornamental bed for your tree, you will prevent some pitfalls associated with placing the tree in the lawn.
Another common mistake is planting a tree too close to a house or other structure. It can be difficult to imagine how large a tree will grow at maturity because it is not a quick process. Trees placed close to houses may grow into eaves and shed leaves onto roofs and into gutters. This adds to maintenance and can provide mosquito breeding grounds. Also, some tree roots may interfere with walkways or septic systems and should be sited far enough away to avoid these issues.
These Japanese Maples are planted in a bed separate from the lawn making care for both plant types easier. Photo: JMcConnell, UF/IFAS
Be sure to research any tree you plan to install to find out ideal growing conditions and mature size. If you plan ahead and use good maintenance practices, a tree can become an valuable part of your home landscape to be enjoyed for years to come.
