by Larry Williams | Oct 1, 2020
Adult cicada on tree branch, Photo credit: Lyle Buss, UF Entomologist
“What is that noise,” asked the visitors to Middle Georgia when I was a teenager. They were visiting during the summer from El Paso, Texas. I asked, “What noise?” The reply, “That loud noise in the trees.” I responded, “Oh, those are cicadas.’ There are sounds that are so common that sometimes you quit hearing them.
Before the visitors left for El Paso, I made sure to show them the brown, dry shells (exoskeletons) of cicadas that are not difficult to find attached to the trunk of a Georgia pine tree during summer. Cicadas leave their nymph exoskeletons on the trunks of trees and sometimes shrubs when they shed them to become mature flying adults.
You may not have ever seen a cicada but you’ve undoubtedly heard one if you live in Florida. These insects make a loud buzzing noise during the day in the spring and summer. Male cicadas produce their distinctive calls with drum-like structures called timbals, located on the sides of their abdomens. The sound is mainly a calling song to attract females for mating.
Cicadas spend most of their life underground as nymphs (immature insects) feeding on the sap of roots, including trees, grasses as well as other woody plants. They can live 10 or more years underground as nymphs. In some parts of the United States, there will be news reports of when periodical cicadas are expected to emerge from the ground. Periodical cicada species mature into adults in the same year, usually on 13- or 17-year life cycles. Their numbers can be enormous as they emerge, gaining much local attention. However, cicada species in Florida emerge every year from late spring through fall and in much smaller numbers as compared to the periodical cicadas.
Cicada emerging from exoskeleton, Photo credit: Lyle Buss, UF Entomologist
There are at least nineteen species of cicadas in Florida, ranging from less than a ¼ inch to over 2 inches in length. Some people might be frightened by their size and sounds but thankfully cicadas don’t sting or bite. They are a food source for wildlife, including some bird species and mammals.
Very rarely, I’ll have someone ask about small twigs from trees found on the ground as a result of the female cicada’s egg-laying process. But because this is usually such a minor issue with practically no permanent damage to any tree, cicadas really aren’t considered to be a pest of any significance in Florida.
For more information on cicadas, contact the University of Florida Extension Office in your County. Or visit the following UF/IFAS web page. https://edis.ifas.ufl.edu/in602
by Larry Williams | Aug 14, 2020
Oleander caterpillars, which are active on some oleanders during summer, can provide a number of gardening lessons.
Oleander caterpillar moth on lantana flower. Photo credit: James Castner, UF
The adult moth is striking in appearance. The bluish to purplish moth has white dots on its black wings. The moths resemble wasps as they fly in and around oleander shrubs.
It’s the orange caterpillars with black spots and black hairs that cause problems for some gardeners.
Caterpillars are the larval stage of butterflies and moths. In order to enjoy watching butterflies and moths feeding on the nectar of flowers, some of the caterpillars must survive to become adult butterflies and moths. This is lesson number one.
Oleander caterpillars usually only feed on oleander plants. Oleanders are native to areas of Europe and Asia. This is lesson number two.
Oleander caterpillar, Photo credit: Paul Choate, UF
Oleander caterpillars benefit by us planting their food source in Florida.
This relationship between pest and plant is referred to as the key plant, key pest concept. Some other examples include St. Augustinegrass and chinch bugs, gardenias and whiteflies, crape myrtles and crape myrtle aphids, azaleas and azalea caterpillars, camellias and tea scale, roses and black spot, pecans and pecan scab, squash and squash vine borers.
Understanding this concept can be helpful in designing a “low maintenance” landscape.
When you plant roses, you plant everything that goes with roses, including the time and money required to maintain them. This applies to St. Augustinegrass, pecan trees, squash and oleanders. This is lesson number three.
Oleander caterpillars can temporarily damage the appearance of oleanders. But they cause no long-term damage for the plant. This is lesson number four. The damage is aesthetic. Oleander caterpillars can consume great numbers of leaves. However, if the plant is otherwise healthy, new leaves will be produced and the plant will continue to grow. The damage is temporary; there will be no evidence the plant ever had a problem.
To spray or not to spray for oleander caterpillars has to do with a person’s tolerance level.
If you can’t tolerate having oleander caterpillars around and the temporary aesthetic damage they cause, consider the use of Bacillus thuringiensis. It is sold under a number of brand names and many times is referred to as Bt. This bacterium only controls caterpillars so it is friendlier for the beneficial insects. When using any pesticide, always follow the label directions and precautions.
Here are links to UF/IFAS Extension publications with more info.
by Larry Williams | Jul 23, 2020
A number of years ago a gentleman told me about an orb weaver spider that was living by his front door. He said that it had been there for about two months and that it was interesting to watch the construction of the intricate “bug catching” web. However, he explained that he had a number of people coming to visit and he wanted to know about relocating the spider to his backyard.
Golden silk orb-weaver spider. Photo credit: UF/IFAS
These types of spiders typically construct their webs in an area and stay in that location based on the environment. Many of the orb weaver spiders rely on flying insects and usually construct their webs several feet or more above the ground. This is a good height to capture many flying insects. As a result, there needs to be items within a reasonable distance to attach and place the web. If a spider is randomly relocated, there may be nothing in reasonable distance to support a web. There needs to be at least a couple of tall shrubs or tree trunks for the spider to construct a web in-between the plants several feet above ground level. It needs to be in an area with limited people movement to prevent disturbance by people walking into it. It needs to be in a location with enough flying insect activity to satisfy the spider. If it’s not the right location, the spider may move back to another location, perhaps the front door area.
Webs built by these types of spiders can be quite large and may be suspended several feet or more above the ground. Some people become annoyed and/or frightened as they accidentally come in contact with these webs, brushing the webs from their face and arms. I’m sure the spider becomes annoyed, too, having to rebuild its web.
Despite their size, orb weaver spiders pose little threat to people. They’re considered beneficial because they feed on a wide range of flying insects. They usually construct webs in relatively sunny, open areas with little wind.
Even though these spiders are beneficial, many people don’t like spiders. If you choose to control spiders in and around your home, keep in mind it’s unwise and impractical, if not impossible, to control all spiders.
By the way, the gentleman concerned about the spider decided to leave the spider at the front door area. He posted a sign next to the web in hopes that his guests would steer clear of the web. He offered his garage entrance to those frightened by the spider.
For more information on orb weaver spiders, visit the below UF/IFAS Extension website.
https://edis.ifas.ufl.edu/topic_orb_weavers
by Larry Williams | Jul 9, 2020
If you’ve been outside this spring, you’ve probably been bothered by gnats. These tiny flies relentlessly congregate near the face getting into the eyes, nose, mouth and ears.
Eye gnats come right up to the faces of people and animals because they feed on fluids secreted by the eyes, nose and ears. Even though eye gnats are considered mostly a nuisance, they have been connected to transmission of several diseases, including pink eye.
Close up of eye gnat. Photo credit: Lyle Buss, UF Entomologist
Eye gnats are true flies. At about one-sixteenth of an inch in length, they are among the smallest fly species in Florida. They are known as eye gnats, eye flies, frit flies and grass flies. The name grass flies is somewhat descriptive as open grass areas such as pastures, hay fields, roadsides and lawns provide breeding sites for these gnats. They also breed in areas of freshly disturbed soil with adequate organic matter such as livestock farms.
Even though these gnats can be found in much of North and South America, they prefer areas with warm, wet weather and sandy soils. Sounds like Florida.
The lack of cold weather in late winter and early spring is the more likely reason for why these gnats are such a problem in our area this year. Without having the typical last killing frost around mid-March and with early warm weather and rains, the gnats got off to an early start.
Short of constantly swatting them away from your face or just not going outdoors, what can be done about these irritating little flies?
By the way, I grew up in an area of Georgia where gnats are common. I’ll let you in on a secret… Folks who live in Georgia are known to be overly friendly because they are always waving at people who are just passing through. More than likely, these “friendly” folks are busy swatting at gnats, not waving at others who happen to be driving by. Swatting is a quick swinging action with hand as if waving.
Because of their life cycle, extremely high reproductive numbers in the soil and because insecticides breakdown quickly, area-wide chemical control efforts don’t work well in combating this insect.
The use of the following where gnats are common can be helpful.
- Correct use of insect repellents, particularly those containing DEET
- Screens on windows to prevent entry of gnats into homes
- Face-hugging sunglasses or other protective eyewear
- Face masks – another use for your COVID-19 face mask
We may have to put up with these annoying gnats until cold weather arrives and be thankful that they don’t bite.
Additional info on eye gnats is available online at https://edis.ifas.ufl.edu/in884 or from the UF/IFAS Extension Office in your County.
by Larry Williams | Jun 23, 2020
The 2020 Atlantic Hurricane Season got off to an early start with some tropical storm activity before the season’s official June 1 start date. We live in a high wind climate. Even our thunderstorms can produce fifty-plus mile per hour winds.
Storm damaged sweetgum tree. Photo credit: Larry Williams
Preventive tree maintenance is key to preparing for storms and high winds.
Falling trees and flying landscape debris during a storm can cause damage. Evaluate your landscape for potential tree hazards. Pruning or removing trees once a hurricane watch has been announced is risky and tree trimming debris left along the street is hazardous.
Now is a good time to remove dead or dying trees, prune decayed or dead branches and stake newly planted trees. Also inspect your trees for signs of disease or insect infestation that may further weaken them.
Professional help sometimes is your best option when dealing with larger jobs. Property damage could be reduced by having a professional arborist evaluate unhealthy, injured or questionable trees to assess risk and treat problems.
Hiring a certified arborist can be a worthwhile investment. To find a certified arborist in your area, contact the International Society of Arboriculture (ISA) at 888-472-8733 or at www.isa-arbor.com. You also may contact the Florida ISA Chapter at 941-342-0153 or at www.floridaisa.org.
Consider removing trees that have low wind resistance, are at the end of their life span or that have the potential to endanger lives or property.
Some tree species with the lowest wind resistance include pecan, tulip poplar, cherry laurel, Bradford pear, southern red oak, laurel oak, water oak, Chinese tallow, Chinese elm, southern red cedar, Leyland cypress, sand pine and spruce pine.
Broken pine from hurricane. Photo credit: Larry Williams
Pine species vary in their wind resistance, usually with longleaf and slash pines showing better survival rates than loblolly and sand pine. However, when pines become large, they may cause a lot of damage if located close to homes or other valuable structures. As a result, large pines are classified as having medium to poor wind-resistance. For this reason, it’s best to plant pines away from structures in more open areas.
Before and after a storm, tree removal requires considerable skill. A felled tree can cause damage to the home and/or property. Before having any tree work done, always make sure you are dealing with a tree service that is licensed, insured and experienced.
More information on tree storm damage prevention and treatment is available online at http://hort.ifas.ufl.edu/woody/stormy.shtml or from the UF/IFAS Extension Office in your County.
