Chiggers, also known as ‘red bugs’ are the larvae of mites in the family Trombiculidae. If you’ve ever got an infestation after being in the woods, you’re familiar with the intense itching and reddish welts they cause. In some parts of the world, they are able to transmit scrub typhus, but luckily for us in Florida, they aren’t known to transmit human diseases.
Microscope view of a chigger. Credit: UF/IFAS.
The life cycle of chiggers consist of an egg, prelarva, larva, nymph and adult. The female will lay her eggs in a sheltered area and the egg will hatch into the prelarva. This is a non-feeding stage. The larva stage is the parasitic stage that feeds on animals and humans, although humans are not their preferred host. During this life cycle stage, they will feed on anything from small mammals to birds, reptiles, and amphibians. You’ll find chiggers in damp, low areas where brush is heavy.
Chiggers use their piercing sucking mouthparts to suck fluids from the skin. After three days of feeding, the larva drops to the ground and transforms into the nymphal stage. The nymph and adult stage have eight legs. The entire life cycle can require two months to one year, depending on temperature, moisture and location.
When chiggers feed on humans, they attach themselves to the skin, hair follicles or pores with their piercing sucking mouthparts. When attached, they are generally not noticed for some time and itching from chigger bites is usually not noticed for four to eight hours after they have been attached or removed. While feeding, they inject a fluid into the skin that dissolves tissue. This fluid injection causes the welts to appear which can last up to two weeks. Contrary to popular belief, chiggers do not actually burrow into the skin and the welts do not contain them.
Chigger bites. Photo credit: Wayne Mitzen, UF/IFAS.
Chiggers can be removed from the skin by taking a hot shower or bath and lathering with soap. Since the symptoms of chigger bites do not appear for several hours after a bite, it is not always possible to prevent welts caused by bites. If welts appear, antiseptic should be used. Temporary itching relief may be achieved by using anesthetics available at the drug store.
If you’re going into areas that may be infested with chiggers, wear protective clothing and use repellents containing DEET. Be sure to apply them to the legs, ankles, cuffs, waist, and sleeves of clothing. Be sure to always follow the label. For more information on chiggers, contact your local UF/IFAS Extension Office.
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Yes, wasps are definitely good guys. Wasps are beneficial insects that feed on other insects, by destroying many harmful bugs that attack our landscape ornamentals and home vegetable gardens. However, they tend not to be very friendly to us, when we encroach on their territory. In other words, we really don’t want them to be close neighbors.
There are five members of the wasp family commonly encountered in Florida. These are hornets (Vespa spp.), yellow jackets (Vespula spp.), paper wasps (Polistes spp.), mud or dirt daubers (Sphecidae spp.), and cicada killers (Specius speciosus). Hornets, yellow jackets, and paper wasps are likely to sting if you go near or disrupt their nests. Mud daubers and cicada killers usually will not sting, unless you touch them.
Photo: Clockwise from top left: Hornet, Yellow Jacket, Paper Wasp, Mud Dauber and Cicada Killer.
Credit: P. G. Koehler and J. L. Castner, UF/IFAS Extension, Department of Entomology and Nematology.
There are parasitoid wasps, such as Tamarixia radiata, that are very beneficial, if you are a citrus grower. This native species is a biological control method for the Asian citrus psyllid, which is the vector for the devastating citrus greening disease. If you are interested in releasing juvenile Tamarixia radiata on your property please visit the Florida Department of Agriculture and Consumer Services website for an application: https://www.fdacs.gov/Divisions-Offices/Plant-Industry/Bureaus-and-Services/Methods-Development-Biological-Control/Biological-Control/Asian-Citrus-Psyllid-Biological-Control/Biological-Control-of-Asian-Citrus-Psyllid-in-Dooryard-Citrus-and-Ornamentals/Tamarixia-Release-Application or call 1-800-435-7352.
So, how do I identify nests? Hornets build football-shaped or pear-like nests usually in trees, away from populated areas, mostly found in the woods. Hornets and yellow jackets seldom live near people. Yellow Jackets build above ground nests, like those of hornets, but more commonly nest in the ground. Paper wasps are frequently found around homes where they construct their honeycomb nests in shrubbery and under eaves. Mud daubers often build their mud-cell nests on the walls and under the eaves of homes. Cicada killers, which are least troublesome of all, nest in the ground. Hornets, yellow jackets, and paper wasps are social insects. They live in colonies, like bees and ants. Mud daubers and cicada killers are solitary wasps.
If wasps do become a nuisance, you can eliminate hornet and yellow jacket nests by calling a certified exterminator of if you are an experienced do-it-yourself home owner, spray the nest opening with a potent wasp and hornet pressurized spray normally found at your local garden center or hardware store. After treating any of the aboveground nests, leave immediately and wait until the wasps are dead. Then, return, knock down the nests, and burn it. To control mud dauber, scrape down their mud cells, and spray the area with an insecticide like pyrethrum or malathion to discourage re-nesting. To treat underground nests, spray with a pyrethrum or Sevin and seal the opening with soil, to keep the insects from escaping.
The severity of reaction to a wasp sting varies drastically, depending on an individual’s sensitivity to the venom. At best, a sting will cause painful swelling. In extreme cases, serious illness, or even death, may result. If a sting victim has a history of hay fever, asthma, or other allergy or if allergic symptoms develop a physician should be contacted immediately
All types of wasp nest should be approached with caution. The best times to apply insecticides are in the early morning or late evening when most of the wasps are in the nest and least active.
For more information, contact your local county extension office.
Supporting information for this article supplied by retired UF/IFAS Extension Entomologist Dr. Don Short and other information can be found in the UF/IFAS Extension EDIS publication: https://edis.ifas.ufl.edu/pdffiles/IN/IN02100.pdf
For more information on Tamarixia radiata, please visit: https://www.fdacs.gov/Divisions-Offices/Plant-Industry/Bureaus-and-Services/Methods-Development-Biological-Control/Biological-Control/Asian-Citrus-Psyllid-Biological-Control/Biological-Control-of-Asian-Citrus-Psyllid-in-Dooryard-Citrus-and-Ornamentals
UF/IFAS Extension is an Equal Opportunity Institution.
The native Florida landscape definitely isn’t known for its fall foliage. But as you might have noticed, there is one species that reliably turns shades of red, orange, yellow and sometimes purple, it also unfortunately happens to be one of the most significant pest plant species in North America, the highly invasive Chinese Tallow or Popcorn Tree (Triadica sebifera).
Chinese Tallow fall foliage. Photo courtesy of Daniel Leonard.
Native to temperate areas of China and introduced into the United States by Benjamin Franklin (yes, the Founding Father!) in 1776 for its seed oil potential and outstanding ornamental attributes, Chinese Tallow is indeed a pretty tree, possessing a tame smallish stature, attractive bark, excellent fall color and interesting white “popcorn” seeds. In addition, Chinese Tallow’s climate preferences make it right at home in the Panhandle and throughout the Southeast. It requires no fertilizer, is both drought and inundation tolerant, is both sun and shade tolerant, has no serious pests, produce seed preferred by wildlife (birds mostly) and is easy to propagate from seed (a mature
Chinese Tallow tree can produce up to 100,000 seeds annually!). While these characteristics indeed make it an awesome landscape plant and explain it being passed around by early American colonists, they are also the very reasons that make the species is one of the most dangerous invasives – it can take over any site, anywhere.
While Chinese Tallow can become established almost anywhere, it prefers wet, swampy areas and waste sites. In both settings, the species’ special adaptations allow it a competitive advantage over native species and enable it to eventually choke the native species out altogether.
In low-lying wetlands, Chinese Tallow’s ability to thrive in both extreme wet and droughty conditions enable it to grow more quickly than the native species that tend to flourish in either one period or the other. In river swamps, cypress domes and other hardwood dominated areas, Chinese Tallow’s unique ability to easily grow in the densely shaded understory allows it to reach into the canopy and establish a foothold where other native hardwoods cannot. It is not uncommon anymore to venture into mature swamps and cypress domes and see hundreds or thousands of Chinese Tallow seedlings taking over the forest understory and encroaching on larger native tree species. Finally, in waste areas, i.e. areas that have been recently harvested of trees, where a building used to be, or even an abandoned field, Chinese Tallow, with its quick germinating, precocious nature, rapidly takes over and then spreads into adjacent woodlots and natural areas.
Chinese tallow seedlings colonizing a “waste” area. Photo courtesy of Daniel Leonard.
Hopefully, we’ve established that Chinese Tallow is a species that you don’t want on your property and has no place in either landscapes or natural areas. The question now is, how does one control Chinese Tallow?
- Prevention is obviously the first option. NEVER purposely plant Chinese Tallow and do not distribute the seed, even as decorations, as they are sometimes used.
- The second method is physical removal. Many folks don’t have a Chinese Tallow in their yard, but either their neighbors do, or the natural area next door does. In this situation, about the best one can do is continually pull up the seedlings once they sprout. If a larger specimen in present, cut it down as close to the ground as possible. This will make herbicide application and/or mowing easier.
- The best option in many cases is use of chemical herbicides. Both foliar (spraying green foliage on smaller saplings) and basal bark applications (applying a herbicide/oil mixture all the way around the bottom 15” of the trunk. Useful on larger trees or saplings in areas where it isn’t feasible to spray leaves) are effective. I’ve had good experiences with both methods. For small trees, foliar applications are highly effective and easy. But, if the tree is taller than an average person, use the basal bark method. It is also very effective and much less likely to have negative consequences like off-target herbicide drift and applicator exposure. Finally, when browsing the herbicide aisle garden centers and farm stores, look for products containing the active ingredient Triclopyr, the main chemical in brands like Garlon, Brushtox, and other “brush/tree & stump killers”. Mix at label rates for control.
Despite its attractiveness, Chinese Tallow is an insidious invader that has no place in either landscapes or natural areas. But with a little persistence and a quality control plan, you can rid your property of Chinese Tallow! For more information about invasive plant management and other agricultural topics, please contact your local UF/IFAS Extension office!
Langeland, K.A, and S. F. Enloe. 2018. Natural Area Weeds: Chinese Tallow (Sapium sebiferum L.). Publication #SS-AGR-45. Printer friendly PDF version: https://edis.ifas.ufl.edu/pdffiles/AG/AG14800.pdf
Attacking mosquitos are spoilers for our outdoor activity interests this time of year. Hurricanes and other storm events tend to be a catalyst that increases these populations. Not only are mosquitos a nuisance, but they are carriers of several diseases. But, there are ways to control these annoying pests and get some relief.
Mosquito populations can be divided into two categories: floodwater mosquitoes and standing water mosquitoes.
Floodwater mosquitoes need water to lay their eggs, and the eggs also need to dry out before hatching during a storm event. Moist areas like pastures, planting furrows, salt marshes and swales are prime habitat. If you look close, the eggs can be found in cracks in the soil. Again, stormy rains and surge act as a catalyst for these eggs to hatch. So, what is the approximate estimate of mosquito eggs per acre in floodwater habitat in Florida? Scientist estimate 700,000 to 1.3 million eggs per acre. And yes, that’s per acre. Unfortunately, small scale efforts to reduce standing water around properties have little effect on control.
Figure 1. Standing water mosquito and eggs (Culex quinquefasciatus).
Credit: S. McCann, UF/IFAS/FMEL.
On the other side of the coin, standing water mosquitos need,…you guessed it, standing water to lay their eggs. These mosquito eggs cannot withstand drying out, therefore cannot hatch into larva. Females lay eggs on the surface of water with a hatching time of around 24 hours. The larva to pupae to adult stage happens quickly in mosquitoes, and the thirst for blood is not far behind. After a female finds a blood source, the cycle starts all over again. Only the females have biting mouth parts. Both male and female mosquitoes feed on the nectar of flowers. It’s the female mosquitoes that usually need a blood meal to insure mature eggs.The combination of the two groups of mosquitoes provide for a double whammy put in place by a storm. When dry areas flood, floodwater mosquito eggs hatch. When floodwater has nowhere to go, standing water mosquitoes have an abundance of places to lay eggs.
Unfortunately, some diseases can be transmitted by mosquitoes, such as west nile virus, eastern equine encephalitis and even heart worms in dogs. So, what can be done to combat these pests around your property? Reducing the amount of standing water helps dramatically, especially, dumping water holding containers. Cleaning debris from rain gutters too, can help as water can collect in blocked gutters. Mineral or cooking oil can be added to standing water and rain collection devices, as the oil forms a thin film on the surface of the water which causes larvae and pupae to drown. This is also a good control method with plant containers that collect water. Mosquito biological controls, like Bt (Bacillus thuringiensis) are helpful and will not harm pets or livestock. These products can be used in fish habitats, animal water troughs, bird baths, rain barrels, roof gutters and tree holes, just to name some. Please read precautionary statements and manufacturer application directions before use. Rain gardens are also very beneficial in suppressing standing water. If you have an area of your property that is known for water holding capacity, be sure to plant water loving plants in that area.
For more information please contact your local county extension office.
Supporting information for this article can be found in the UF/IFAS EDIS publication: “Hurricanes and Mosquitos” by C. Roxanne Connelly: https://edis.ifas.ufl.edu/pdffiles/IN/IN53500.pdf
UF/IFAS Extension is an Equal Opportunity Institution.
As we continue our series on marine life in the Gulf of Mexico, we also continue our articles on marine worms. Worms are not the most charismatic creatures in the Gulf, but they are very common and play a large role on how life functions in this environment. Roundworms are VERY common. There are at least three phyla of them but here we will focus on one – the nematodes.
A common nematode.
Photo: University of Florida
Most nematodes are microscopic, a large one would be about 2 inches, and some beach samples have found as many as 2 million worms in 10 ft2 of sand. So, what do we know about them? What role, or function, do they play in the ecology of the Gulf of Mexico?
Well first, they are long and round – cylinder shaped. There is a head end, but it is hard to tell which end is the head. Round is considered a step up from being flat in that it can allow for an internal body cavity. An internal body cavity can allow for the development of internal body organs. Internal body organs can move large amounts of nutrients, blood, oxygen, and hormones around the body allowing the animal to become larger. Some argue that a larger body can have advantages over smaller ones. Some say the opposite, but either way – a large body has been successful for some creatures and an internal body cavity is needed for this.
That said, the nematodes do not have a complete internal body cavity. So, they do not have a complete assortment of internal organs. Being round reduces your efficiency in absorbing enough needed nutrients, oxygen, etc. through your skin alone and this MAY be a reason they are small. They are very small.
There are free living and parasitic forms in this group. There are at least 10,000 species of them, and they can be found not only in the marine environment, but also in freshwater and in the soil found on land. They have played a role in the success of agriculture, infesting both crops and livestock. Nematodes can be a big concern for farmers and gardeners.
The free-living forms are known to be carnivorous, feeding on smaller microscopic creatures. They have toothed lips, and some have a sharp stylet to grab or stab their prey. Some stylets are hollow and can “suck” their prey in. Moving through the environment, they can consume algae, fungi, and diatoms. Some are deposit feeders and others are decomposers. On our farms and in our gardens, they are known to enter plants via the roots and can be found in the fruit.
The life cycle of the human hookworm.
The parasitic version of nematodes has been a problem for some species. In humans we have the hookworms and pinworms. Dogs have their heart worms. An interesting twist on the parasitic nematode way of life, compared to flatworms like tapeworms, is their lack of a secondary (or intermediate host). The entire life cycle can take place in the same animal.
Females are larger than males and fertilizations is internal. Males are usually “hooked” at the tail end and hold on to the females during mating. About 50 eggs will be produced and released into the digestive tract, where they exit the animal in the feces and find new hosts either by the feces being consumed or drifting in the water column.
There multiple forms of parasitism in nematodes.
– Some are ectoparasites (outside of the body) on plants.
– Some are endoparasites in plants – some forming galls on the leaves.
– Some infest animals but only as juveniles.
– Some live-in plants as juveniles and animals as adults.
– Some live-in animals as juveniles and plants as adults.
It would be fair to say that many forms of marine creatures have nematodes living either within them, or on them. Some can be problematic and cause disease; some diseases can be quite serious. Others play an important role in “cleaning” the ocean, filtering the sand of organic debris. Many have heard of nematodes but know little about them. Either good or bad, they do play roles in the ecology of the Gulf of Mexico.
Article By: Whitney Cherry
4-H Agent Calhoun County
I know COVID-19 has been driving public and private discussion as of late. But, we have to stay vigilant in working against all public health threats. One of those threats we typically start talking about this time of year is mosquito borne illnesses and preventative mosquito control. Not only are mosquitoes pests, but they can transmit some pretty nasty diseases we wouldn’t want under normal circumstances. But with our healthcare system currently inundated with COVID-19 patients, we certainly wouldn’t want to unnecessarily add to the burden.
Adult female yellow fever mosquito, Aedes aegypti (Linnaeus), in the process of seeking out a penetrable site on the skin surface of its host.
Credit: James Gathany, Center for Disease Control Public Health Image Library Source: https://edis.ifas.ufl.edu/in792
So what’s the reality? While the incidence of mosquito borne illness is much lower with the advent of modern medicine and basic public practices of wearing bug spray and dumping or treating standing water, it’s definitely not unheard of. The Zika scare is not such a distant memory after all. And EEE (eastern equine encephalitis) was at an unusual high last year in horses in the panhandle. So what can we do?
With recent flooding in some areas and the weather warming, we can expect to see increasing populations of mosquitoes. Additionally, as the weather warms, we all tend to spend more time outside, increasing our likelihood of mosquito bites. Further exacerbating the situation is the widespread quarantine measures keeping many of us home. The late afternoon and early evening hours bring ideal weather to step outside and enjoy a little time away from TV and computer screens. We encourage fresh air and exercise outdoors, but we also encourage basic safety. So wear bug spray if you’re outside early morning and especially near, during, or shortly after dusk. Wear long sleeves and pants and socks if you can stand it. And keep standing water dumped out of containers on your property. If this isn’t possible, look for safe water treatment options. The most prevalent spreaders of disease (Aedes aegypti) actually require these containers of water to complete their lifecycle.
For more information on this or other Extension-related topics, call or email your local extension office.
Related information: http://edis.ifas.ufl.edu/results.html?q=mosquito+borne+illness&x=0&y=0#gsc.tab=0&gsc.q=mosquito%20borne%20illness&gsc.page=1