by Evan Anderson | May 20, 2021
A number of landowners in our region have been noticing a number of caterpillars coming down from the treetops. Sometimes appearing in vast numbers, the forest tent caterpillar has been found throughout Florida and the United States. Several years of heavy infestation occurred in Central Florida more than a decade ago, but populations are usually not high enough to cause significant damage to trees.
A forest tent caterpillar. – Photo courtesy of Shoal Sanctuary Nature Preserve.
The forest tent caterpillar is the larval stage of a somewhat nondescript brown moth. The moths lay their egg masses on twigs, and the eggs hatch in the spring. Caterpillars feed on a variety of tree species, but seem to prefer oak and gum trees. They spend anywhere from two to six weeks eating. When they are nearing maturity, they can become a problem for humans who do not appreciate the many droppings they produce, or their habit of descending from the trees to find places to spin their cocoons. They are sometimes attracted to lights or the walls of buildings, where they congregate in search of a place to pupate. They are not harmful to people, however.
A forest tent caterpillar egg mass. – Photo courtesy of Jeffrey Lotz, Division of Plant Industry
Particularly cold winters may help decrease populations of these caterpillars. Inclement weather or high temperatures may do the same in the summer, and natural predators often help to control populations when present as well. Controlling forest tent caterpillars is most often unnecessary even when there are large numbers of them. It may help to avoid parking cars under large infestations or to turn off outdoor lighting that might attract them at night. If they wander indoors, check screens and window seals to be sure there are no gaps for them to enter.
If these or other caterpillars become such a nuisance that control measures must be considered, consider using a product such as Bacillus thuringiensis, or Bt, which specifically affects caterpillars and not other beneficial insects. Keep affected trees healthy with proper fertilization and watering, and even a defoliated tree will probably recover from any damage these insects cause. For more information, see our EDIS publication on the Forest Tent Caterpillar or contact your local Extension office.
-Evan Anderson, Walton County Horticulture Agent.
by Matt Lollar | Apr 1, 2021
If you’ve been raking leaves recently, you’ve probably noticed little green worms hanging from the trees. They seem to be in abundance this year and can be found crawling on driveways, just hanging around, and maybe even feeding on oak tree leaves.
These green worms that are all over the yard are oak leafrollers (Archips semiferanus) or oak leaftiers (Croesia semipurpurana). Some people may refer to them as inchworms, however a number of different caterpillars can go by that name. Leafrollers and leaftiers range in length from 1/4″ to 1″. The adult form of these insects is a 1/2″ long moth. The oak leafroller moth is mottled tan and brown and the oak leaftier moth is yellow with brown markings.
An oak leafroller caterpillar crawling on a leaf. Photo Credit: Blair Fannin, Texas A&M University
In May, the adults of both species lay their eggs in the twigs and leaf buds of a number of tree species. The eggs don’t hatch until March of the following year. When the caterpillars emerge, they feed on the newly forming leaves and flowers of oak, hackberry, pecan and walnut trees. If they are disturbed, they will stop feeding and hang from a strand of silk. Oak leafroller caterpillars pupate in tree branches, while oak leaftier caterpillars drop to the ground and pupate in leaf litter. Adult moths emerge in one to two weeks.
A leafroller moth with wings spread. Photo Credit: U.S. National Museum
The oak leafrollers and oak leaftiers don’t really do enough damage to be considered pests, but they are a bit of a nuisance. Thankfully, birds and parasitic wasps will eat and kill the majority of the population. For in-depth information on most of the interesting insects in your yard, please visit the UF/IFAS Featured Creatures Website.
by Les Harrison | Aug 10, 2018
Looks, as the old saying goes, can be deceiving. It is a cautionary pronouncement from experience, usually painful and expensive, to serve as a warning to those who follow and hopefully avoid similar complications if they listen.
In most situations a threat in nature can be easily identified and avoided with a little effort. Except for those situations where the careless or clueless individual blunders into problems, a little observation and logic dictates the potential outcome from a close encounter.
Yellow jackets have stingers, so they must stink something. Alligators would not have all those large and pointed teeth unless they needed to bite something.
Those assumptions are easily deduced by anyone who uses even the slightest quantity of judgement and forethought. Unfortunately, there are occasions where the potential agony is disguised by bright colors and a benevolent appearance.
Such is the case with the caterpillar of the Io moth. Automeris io, this insects entomological name, is a large native moth.
This insects’ range extends from south central and maritime Canada to the eastern half of the U.S. It is found in every Florida County, even into the Keys.
The wingspan of this moth can reach an impressive three and a half inches. Males of this species tend to have a slightly brighter appearance than the females.
Both sexes have large eye spot on each hindwing as a defense device. When revealed, the spots appear as the eyes of predatory creature meant to bluff other aggressors into retreating.
Adults of this species live only a week or two, so reproduction is a priority activity. Luckily, at least for the parents, there are plenty of host plants in north Florida.
Oaks, sweetgums, redbuds, and ash are among the choice meal sites for the developing caterpillars. The eggs are commonly laid in clusters of 20 or more and the caterpillars go through five development stages before reaching adulthood.
Unlike the parents which are active almost exclusively at night, the larvae spend their days hidden in the tree leaves they are consuming. These caterpillars are quite animated and active, frequently seen moving inline from one feeding site to another.
Initially orange, they change to a lime green as they mature. They also develop clusters of spine strategically place across their plump bodies.
Photo Caption: The colorful Io moth caterpillar is covered by fragile spines. Each contains a painful venom for anyone who physically contact this insect larvae.
Distinct from their parents’ eyespot bluff, the spines are a serious defense designed to assure the caterpillars reach maturity unmolested by birds or other predators which would otherwise find them a suitable snack option.
Unlike a pit viper which injects venom via a syringe-like fang or a stingray which retains its barb in a venom saturated sheath, this caterpillar’s spines work differently. Each spine contains a sac filled with the defensive solution.
When contact is made with the hollow spines, deliberately or accidentally, the fragile structure breaks and releases the toxin. The pain is almost instantaneous, intense, and can be a serious health treat for those who have an allergic reaction.
Not usually seen on the ground this caterpillar can be encountered on lower limbs, to the detriment of the unlucky individual. The colorful, toy-like appearance hides a very different reality.
To learn more about north Florida’s stinging caterpillars, contact the local UF/IFAS County Extension Office. Click here for contact information.
by Julie McConnell | Sep 29, 2015
Giant Swallowtail on citrus leaf. JMcConnell, UF/IFAS
Adult butterflies are pretty easy to attract to your landscape if you provide flowering plants, but getting them to lay eggs in your garden is a little trickier.
Butterflies go through complete metamorphosis which means that they have four main life stages. The first is the egg, second they hatch into caterpillars (larvae) which feed and molt many times, the third stage is the pupa or chrysalis, and finally they emerge as colorful adults. Complete metamorphosis is considered a more advanced life cycle than incomplete and one of the reasons is because most insects that go through this process do not compete for food at different life cycles. For example, the gulf fritillary butterfly larvae needs passionflower (Passiflora spp.) to feed on – no other plant type will do. The adults visit many flowering landscape plants such as zinnias, butterfly bush, pentas, etc. The adults are feeding on nectar while the caterpillars are eating foliage.
Because the larvae are very host specific, you must offer the correct plant to attract particular butterflies. Luckily, we have many options in the Florida panhandle! Just remember if you would like to attract butterfly breeding to your yard, you must sacrifice some foliage to support the caterpillars.
• Gulf Fritillary – Passionflower
• Monarch – Native milkweed
• Giant Swallowtail – citrus
• Eastern Black Swallowtail – plants in the carrot family including dill, celery, fennel, and parsley
• Tiger Swallowtail – sweet bay magnolia, tulip poplar, black cherry
• Zebra Swallowtail – pawpaw
• Luna Moth – walnut, hickory, sweetgum, persimmon, winged sumac
If you would like to know more about individual butterfly species please visit UF/IFAS Entomology & Nematology’s Featured Creatures website.
by Roy Carter | Jun 10, 2015
Saddleback Caterpiller, Image Credit Matthew Orwat UF/IFAS
The four major stinging caterpillars occurring in Florida are the Puss Caterpillar, Saddleback Caterpillar, IO Moth Caterpillar and Hag Caterpillar. Some less common ones also occur in the state. These caterpillars do not possess stingers, but have spines (nettling hairs) that are connected to poison glands. Some people experience severe reaction to the poison released by the spines and require medical attention. Others experience only an itching or burning sensation.
Stinging caterpillar’s feed on many pants, but they seldom are present in large enough numbers to cause serious damage. Their stings, rather than feeding, pose the primary threat. That’s why it’s important to learn to recognize and avoid these cantankerous crawlers. My information on stinging caterpillars was provided by Extension Entomologist Dr. Don Short and Dr. D. E. Short of the University of Florida’s Institute of Food and Agricultural Sciences
The puss caterpillar is stout bodied, almost an inch long, and completely covered with gray to brown hairs. Under the soft hairs are stiff, poisonous spines. When touched, the spines break off in the skin, causing serve pain. The saddleback caterpillar has a more striking appearance. It’s brown, with a wide green band around the middle of the body. There’s a large brown spot in the middle of the green band, giving the appearance of a brown saddle on a green blanket. The saddleback may exceed and inch in length, and is stout bodied. The main poison spines are born on pairs of projections near the front and rear of the body. There’s a row of smaller stinging organs along each side.
I O Moth Caterpillar, Image Credit UF Entomology
The IO moth caterpillar is pale green, with yellow and reddish to maroon stripes along the sides. It often exceeds two inches in length, and is fairly stout bodied. The poisonous spines, which form rows of bands across the body, are usually yellow with black tips.
The light brown hag moth caterpillar has nine pairs of variable length protrusions along its body, from which poisonous spines extend. The protrusions are curved and twisted, giving the appearance of disheveled hair of a hag.
Most contact with stinging caterpillars occurs in the spring and summer. As might be expected, children, campers, and gardeners are most frequent victims. When playing or working outdoors in infested areas, it pays to wear a long-sleeved shirt, long pants, and gloves.
Reactions to caterpillars poison vary with an individual’s sensitivity. Itching, burning, swelling, and nausea may be experienced. In severe cases, fever, shock, and convulsions may occur. If a person has a history of hay fever, asthma, or allergy or if allergic symptoms develop a physician should be contacted immediate. In cases of milder reactions, a strip of adhesive tape should be placed on and pulled off the affected area repeatedly to remove the spines. Then, apply ice packs, followed by a paste of baking soda and water.
Since so few stinging caterpillars are normally found on plants around the home mechanical methods usually offer the easiest means of control. Just carefully remove and crush the caterpillars, or knock them into a pan of kerosene. If a pesticide is needed, Bacillus thuringiensis (Bt), Seven or Malathion may be used in accordance with label directions for caterpillar control.
For more information on Caterpillars contact your UF/IFAS County Extension Service or visit www.http://edis.ifas.ufl.edu and see Publication 107 – Stinging and Venomous Caterpillars.
Puss Caterpillar, Image Credit University of Florida
