How many blissful summer days have been disrupted in Florida by biting or stinging insects? More than a few. Mosquitoes, fire ants, yellow flies, dog flies, no-see-ums, yellowjackets, and more all live in our area and are either gleefully happy to violently defend their territory or actively seeking people out as food. One more creature to add to the list, though it is technically an arachnid rather than an insect, is the chigger.
Chiggers, also known colloquially as red bugs, are the larvae of mites in the family Trombiculidae. They are difficult to see, even as adults, because of their diminutive size. They’re tiny. So tiny, in fact, that you may not be able to feel them even if they’re crawling all over you. They don’t seem to have any claustrophobia, rather enjoying the tightest spaces under clothing and spots where skin is thin and tender. This leads to bites in some very uncomfortable places. When they bite, chiggers temporarily attach themselves to their host and inject a digestive fluid into the skin. This triggers an immune response in people; our bodies don’t seem to like being partially digested and sucked up by tiny critters. Even if the body’s response means the mite doesn’t finish its meal, it still leaves a mark. Different people may have varying sensitivity to the bites, but it is never a pleasant experience. Itching sets in four to eight hours after the bites, which may be accompanied by red welts or bumps on the skin. Severe reactions may lead to fever.
Chigger. Photo Credit: University of Florida/IFAS
Chiggers do not attach themselves permanently to people, nor do they burrow under the skin. If you’re lucky enough to discover any mites still biting you, take a hot shower and lather with soap several times. Nail polish applied to the bites will not help, though strangely enough meat tenderizer may help with the itching. Antiseptic is always a good idea as well, and if you’re short on meat tenderizer, an over-the-counter anti-itch product will serve too.
To avoid running afoul of chiggers, be aware that they are most likely to be found in low, damp areas outdoors with shrubby vegetation. They may be found elsewhere, but one persistent myth is that they like to inhabit Spanish moss. In reality, they don’t have any particular attraction to it.
Thankfully, insect repellants that contain DEET repel chiggers as well as other pests. For maximum effectiveness on chiggers, apply repellants to sleeves and cuffs of pants, as well as waistlines.
How often do we stop to think of the importance of pollinators to food security?
Pollination is often described as the transfer of pollen grains from the anther to the stigma of a flowering plant. These transfers are made possible due to pollinator visits in exchange of pollen and nectar from the plants.
Who are our pollinators?
Main Global Pollinators
Social Solitary
Honeybees Alfalfa leafcutter bee
Bumble bees Mason bees
Stingless bees Other leafcutter bees
How can we care for pollinators?
We can care for our pollinators by growing plants that have abundant and accessible pollen and nectar.
Choose plants with flat flowers or short to medium-length flowers tubes (corollas), and limit plants with long flower tubes such as honey suckle.
Avoid plant varieties that do not provide floral rewards (pollen), which is the essential food source for bees. (e.g., some sunflower, and lilies).
While we think of most flies as pests, garden flies, such as Allograpta obliqua species found in Florida, are excellent pollinators and insect predators. Photo by Jessica Louque, Smithers Viscient, Bugwood.org.
Many native wild bees have relatively short proboscises, or tongues, and may not be able to access nectar from flowers with long tubes; however, flowers with long floral tubes can attract other pollinators with long tongues or beaks such as butterflies, moths, and hummingbirds.
Arewe creating an ecosystemaesthetically pleasing while attracting pollinators?
UF/IFAS Photo: Tyler Jones
The planting of native wildflowers in Florida can benefit agricultural producers likewise, native pollinators and other beneficial such as parasitoids and predators.
Some of the main benefits of growing native wildflower are:
Increasing wild bee presence in the surroundings
Providing nesting and foraging sites for pollinators, butterflies, bees etc.
Increasing natural enemies of pest insects.
It is important to select mix varieties of native wildflowers when restoring habitats for our pollinators. Mix varieties will flower all year round and make available a continuous supply of nectar and pollen. If possible, use wildflower seeds that are produced in the state that you want to carry out pollinator restoration. It is highly likely that one will experience better growth from locally produced seeds because they will adapt better to regional growing conditions and the climate. For optimum flowering and high production of floral rewards such as pollen and nectar, place wildflowers in areas free of pesticides and soil disturbance.
Most bee species are solitary, and 70% of these solitary bees’ nest in the ground. A wildflower area of refuge can fulfill the shelter resource needs of these bees since that area will not undergo regular tilling, thus minimizing nest disturbance.
For some common native wildflowers of north Florida, you can see: Common Native Wildflowers of North Florida by Jeffrey G. Norcini : https://edis.ifas.ufl.edu/pdf/EP/EP061/EP061-15448828.pdf and Attracting Native Bees to Your Florida Landscape 1 Rachel E. Mallinger, Wayne Hobbs, Anne Yasalonis, and Gary Knox: IN125500.pdf (ufl.edu)
Insects use pheromones to attract their mates and communicate with each other. Ants use pheromones to tell fellow ants where to find food. Aphids use pheromones to warn each other about potential predators. And all insects use pheromones to call for a mate.
So what exactly are pheromones? Pheromones are substances that are secreted by an individual and received by another individual of the same species. In humans, pheromones are most commonly found in sweat and detected by the olfactory system. Most animals have a functioning vomeronasal organ inside their noses to detect and process pheromones. However, it is debatable whether adult humans possess a functional vomeronasal organ.
Although most of us may not be able to detect insect pheromones, scientists have been able to identify and synthesize the pheromones of many economically important insects. These pheromones are impregnated on rubber and plastic dispensers and placed in different types of traps depending on the pest. The pheromone traps attract males of the target species. These traps are commonly used for monitoring, but in some cases can be utilized to disrupt mating habits which can help control some pests.
The most common pheromone trap in this part of the country is probably a boll weevil trap. Growing up, I thought they looked like little green lighthouses. These traps consist of a yellow-green cannister with an inverted funnel on top that contains the pheromone. While you may not be growing cotton in your home garden, there are some other common insect pests you may want to monitor and possibly disrupt.
Pecan nut casebearer trap with pheromone bait. Photo Credit: UGA Cooperative Extension
Pecan Nut Casebearer (PNC) – These moths are gray with a dark line of scales on their forewings. PNC moths are about 1/3 inches long. They lay their eggs on the outside of pecan husks in April/early May. Their larvae bore into the base of developing nuts and remain inside the nuts for four to five weeks to feed then pupate. A tent-type trap with pheromone can be hung in a pecan tree in April or May to help monitor for this insect. Depending on how many trees you have, multiple traps can be installed to possibly disrupt the mating cycle of this pest.
A yellow sticky trap with Asian citrus psyllids circled. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Asian Citrus Psyllid (ACP) – These tiny insects are about the size of the tip of a pencil (about 1/8 inches long). They vector the Huanglongbing (HLB) disease also known as citrus greening. This disease blocks the nutrient uptake tissue of citrus trees and eventually kills infected trees. Traps consist of a yellow sticky card with a pheromone bait sometimes impregnated on the twist tie hanger. The citrus industry has been heavily impacted by citrus greening, so monitoring for this pest is very important.
An abundance of clearwing moths on a pheromone trap that has been pulled apart. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County
Clearwing Moth – There are numerous species of clearwing moths that bore into the trunks of fruit and ornamental trees and shrubs. One of the most common is the peachtree borer. These insects don’t look like a typical moth. Instead, they resemble wasps. Tent-type pheromone traps can be used to monitor for clearwing moths and potentially disrupt their mating habits. Another common clearwing moth is the ash borer (lilac borer). As their name would suggest, these moths bore into the wood of ash trees, but they also like various Ligustrum species and olive trees.
These are just a few of the species of insects that can be monitored by pheromone traps. To help with the timing of trap dispersal and placement, you should get a grasp of concept of “Degree Days”. Degree day accumulation is used to predict important life events for particular insects such as the average egg laying date, egg hatch date, and larval development. More information on calculating degree days can be found in the article “Predicting Insect Development Using Degree Days” from the University of Kentucky. Fortunately for us, we can skip some of the math by utilizing the AgroClimate Growing Degree Days Calculator. Simply select the weather station closest to you on the provided map and a graph will appear.
Sweet Viburnum (Viburnum odoratissimum) is thought of as being an ironclad landscape shrub, generally a rapid, healthy grower free of insects and disease. However, this spring, many Sweet Viburnum specimens across the Panhandle have experienced varying degrees of dieback, from individual shoots to entire sections of shrubs, caused by the fungal pathogen Botryosphaeria – commonly known as Bot Rot.
Typical symptom of Bot Rot on Sweet Viburnum. Photo courtesy of Daniel Leonard.
Bot Rot almost always appears after some kind of major stress event that impacts susceptible plants – drought, pruning wounds, nutritional deficiencies, or another environmental stress. We haven’t been afflicted lately with any serious drought conditions and the disease occurrences are too widespread to have been a result of isolated pruning or poor plant nutrition. However, the Panhandle did experience a major environmental event around Christmas 2022 that was plenty stressful for landscape plants, a weeklong Arctic blast of extreme cold. This abrupt hard freeze event in an otherwise mild winter is my best guess for what brought about the increased incidence of Botryosphaeria we have experienced this spring.
The Botryosphaeria fungus enters plants via wounds – in this case one probably caused by cold – and begins destroying the plant’s vascular system in the area. As the pathogen progresses, it eventually causes sunken cankers to appear, girdles the affected branch, and cuts off “circulation” in that stem. The first symptom of Bot Rot that gardeners notice is shoots rapidly wilting and exhibiting a blighted appearance, with brown, dead leaves holding onto affected limbs. Unfortunately, dieback isn’t always limited to individual shoots and can spread back into plants to eventually encompass whole branches. Entire plants dying from Bot Rot infection is not uncommon.
While there aren’t any fungicides that are effective in controlling or preventing Bot Rot, gardeners can arrest its spread by pruning out infected branches. To completely rid the plant of the fungus, make sure to prune 4” or so below the last infected plant tissue (symptomatic tissue will appear dark and discolored; healthy tissue will appear light and greenish). After pruning each affected plant, it is important to sanitize pruning equipment with either a 10% bleach solution or 70%+ isopropyl alcohol to prevent spreading pathogens to other healthy plants! Plants that have been irreparably disfigured by Bot Rot or outright killed may be pulled and discarded offsite.
While this year’s Bot Rot infestation has been extremely frustrating and similar future freeze events can’t be ruled out, gardeners should not give up on Sweet Viburnum, an excellent specimen or screening shrub. Keeping plants healthy with proper pruning, good fertility, and adequate irrigation is the best defense to ward off future infection when we experience harsh environmental conditions! For more information on Bot Rot, Sweet Viburnum, or any other horticultural topic, contact your local UF/IFAS County Extension Office! Happy Gardening.
This week I have been noticing some of the beautiful perennials blooming at the Jackson County Extension office, and one struck me as especially beautiful. Indian Pink or Woodland Pinkroot (Spigelia marilandica), it turns out, is native to several counties in the Florida Panhandle.
Woodland Pinkroot, Indian Pink. Flower Closeup. Image Credit: Matthew Orwat, UF/IFAS Extension
Woodland Pinkroot is a long-lived perennial that has a very showy but short blooming cycle each spring. It thrives in part shade as a small shrublike forb between 2-3 feet tall. Zones 8a and 8b are its native range in Florida and it is often found in moist, sandy, and well-drained acidic soils. This is not a plant that will tolerate salty soils or salt spray, so planting on the coast is not recommended. Additionally, it dies to the ground in the winter, so care must be taken when weeding the garden to preserve this perennial from inadvertent destruction.
This showy native is easy to propagate from seed or root division but not from cuttings. What’s more, it attracts hummingbirds with its tubular-shaped yellow and red flowers. Old flowers may be removed before seed set to extend the blooming season. One advantage for the urban garden is that it is not an aggressive grower but will need some help if competing with other aggressive native plants such as blue mistflower (Conoclinium coelestinum).
Spigelia marilandica or Indian Pink, in full flower. Image credit: Matthew Orwat IF/IFAS Extension
This is one plant that I was not aware of until recently as it seems to be not well known even to long-term Florida gardeners. I think that it is a worthy addition to the native or Florida Friendly landscape if one has the right climatic conditions for it to thrive, namely partial shade and well-drained, moist, and acidic soil.
For more information check out these popular native plant websites:
