Fire Ants Spreading Like Wildfire – Ways to Co-Exist with this Invasive Species

Fire Ants Spreading Like Wildfire – Ways to Co-Exist with this Invasive Species

Donna Arnold, University of Florida/IFAS Extension - Gadsden County

Written by: Donna Arnold, University of Florida/IFAS Extension – Gadsden County

Have you ever noticed mounds of dirt popping up on your lawn, in your cattle pastures, and other places? You just might be experiencing an ant invasion. The Red Imported Fire Ant, (referred to hereafter as RIFA) came from South America in the early 1900s through the port of Mobile, Alabama. Today, they have spread across the US and have become a serious pest causing significant social, environmental, and economic impacts. RIFA mounds can be seen in well-manicured landscapes, but also can nest around tree roots and stumps, as well as under pavement, buildings, and indoor areas. Although RIFA do prey on flea larvae, chinch bugs, cockroach eggs, ticks and other pests, however the problems they create usually outweigh their benefits.

Lifecycle/description.

Red Imported Fire Ant

Red Imported Fire Ant. Photo Credit: University of Florida/IFAS

Size determines the lifespan of RIFA workers. Minor workers may live 30 to 60 days, media workers 60 to 90 days, major workers 90 to 180 days, and queens may live two to six years. Complete lifecycle from egg to adult takes between 22 and 38 days. RIFA are 1/8” to 1/4” long and reddish-brown or black in color.

RIFA usually respond rapidly and aggressively when disturbed. They clamp onto their victims with powerful jaws and sting repeatedly while injecting painful venom. The stings cause a burning sensation and itching blisters that can become infected. Although very uncommon, in severe cases, the stings can produce shock or cause death.

Where one can find RIFA

winged ants

Winged alates preparing for nuptial flight. Photo Credit: Donna Arnold, University of Florida/IFAS Extension – Gadsden County

RIFA frequently invade home lawns, school yards, athletic fields, golf courses, parks, and other recreational areas. Additionally, electrical equipment and utility housing, home gardens, compost piles, mulched flowerbeds, pavement cracks, and the perimeter of bodies of water must all be considered when choosing a method of control.

Management

Two approaches can be taken to effectively manage RIFA.

  1. Single mound treatments
  2. Area-wide broadcast applications

Six methods of single mound treatment are available.

Mound Drenches. Large volumes of liquid toxic to ants are poured over a mound. Liquids can range from using several gallons of hot water to insecticides mixed with several gallons of water. This method may not reach the queen, therefore, not preventing colony elimination.

Surface Dusts. Similar to mound drenches, a dust or granular insecticide is applied over the top of the mound and then watered into the soil.

Mound Injections. The use of insecticides that may be pressurized and injected into a mound. Often this method is more expensive, but more effective, than mound drenches; however, more time may be required for this method.

Baits. Baits can be used for both individual mound and broadcast applications. A small amount of the bait is sprinkled around the mound and the ants then forage and bring the bait back to the colony to feed on. This method is slower acting, but more effective than drenching, dusting, or fumigating a mound because the workers will feed the bait to the queen and brood, thus gaining effective control of the colony.

Mechanical Control. Certain mechanical and electrical devices are on the market for controlling fire ants, but the efficacy has not been documented.

Home Remedies. Many homeowners will choose to pour boiling water or ignite flammable liquids over a mound. While these methods may bring about control, they are not recommended because they are both very dangerous, not only to humans, but also to the environment. Several other myths often circulate by the media or by way of word of mouth, often times these methods are anecdotal.

Area-wide broadcast applications

Currently, there are only a few products available for broadcast treatment of large areas. These products are either granular insecticides or baits composed of soybean oil and toxicant on a corn grit carrier. These granules are broadcast over a large area and are carried to the colony and fed to nestmates and the queen. This is a very effective application but does present problems because (1) ants may not find it, (2) do not feed upon the bait, and (3) some baits are light sensitive (as with hydramethylnon) and may inactivate before discovery by the ants. Reinfestation of any treated area, whether by broadcast treatment or individual mound treatment may occur.

As a result, other methods such as Biological Control is widely used to mitigate control of the RIFA.

Supporting information for this article can be found in the UF/IFAS EDIS publications (Managing Imported Fire Ants in Urban Areas) visit https://edis.ifas.ufl.edu/publication/lh059 and Red Imported Fire Ant, Solenopsis Invicta Buren (Insecta: Hymenoptera: Formicidae: Myrmicinae)  https://edis.ifas.ufl.edu/publication/IN352.

 

 

 

 

 

 

 

 

 

Gardening in the Panhandle LIVE Program Summary: Houseplants

Gardening in the Panhandle LIVE Program Summary: Houseplants

Houseplants can soften up the interior of your home and help clean the air.  They can also supplement your holiday decorations and help create stunning focal points.  To help determine what plants do best under certain conditions and to give pointers on plant care, this month’s Gardening in the Panhandle LIVE! was all about houseplants.

spides plant

A spider plant on a coffee table. Photo Credit: University of Florida/IFAS

Environmental Conditions for Houseplants

Unless you live in a glass house, you’ll probably want to choose houseplants that do well in low light conditions.  A guide for what light level different houseplants prefer can be found on the Gardening Solutions Light for Houseplants page.  This page also provides useful tips on supplemental lighting.

Some houseplants are better at cleaning the air than others.  A list of houseplants that do a good job improving indoor air quality can be found on the Gardening Solutions Houseplants That Clean the Air page.

The best way to determine if your houseplants need water is your own green thumb or whatever finger you choose to stick in the potting mix, but for some interesting information on outdoor soil moisture meters check out this informative publication on soil moisture sensors.

Houseplants need a good quality, well-drained potting mix to thrive.  Tips on selecting a potting mix can be found on the Gardening Solutions Container Media page.

Houseplant Pests

One of the best ways to rid houseplants of insect pests is to set the plants outside for a few days and let the pests move on.  For some information on pest control products in and around the home check out the publication Natural Products for Managing Landscape and Garden Pests in Florida.

Fungus gnats are mainly a nuisance, but some species can feed on living plant tissue.  Darkwinged fungus gnats are known to feed on ferns, orchids, and geraniums.

Houseplant Propagation

One way to increase your houseplant population and save a few dollars is to propagate your own plants.  The University of Florida/IFAS created the Plant Propagation Glossary to help with any propagation questions you may have.

Air layering is a propagation technique that not only allows the prospective plant to thrive from the nutrients of the mother plant, but it also saves space.

moth orchid

A moth orchid (Phalaenopsis spp.) outdoors. Photo Credit: University of Florida/IFAS

Specific Species Info

Orchids in the genus Phalaenopsis are easier to care for than other genera of orchids.  The American Orchid Society provides some great tips on caring for orchids indoors.  Some people choose to water their orchids with ice cubes.  The Ohio State University has a publication that provides some more insight on watering Phalaenopsis orchids with ice cubes.

A lot of cacti do well indoors.  A popular cactus during the holiday season is Christmas cactus.  Christmas cactus have interesting foliage, but their blooms are what people want to see.  Some tips on getting your Christmas cactus to bloom on time and general care information can be found in this Christmas Cactus Preparation fact sheet.

Have you ever wanted to grow fruit trees indoors or do you want some tips on bringing containerized fruit trees indoors for the winter?  The Growing Fruit Crops in Containers publication provides some good tips on growing fruit trees indoors.

Unless you have a house with a lot of windows or a sunroom, plumeria don’t make the best houseplants.  They need at least six hours of sunlight per day and need to be at least three years old to bloom.  If you are interested in propagating plumeria, then check out this publication on propagating plumeria from cuttings.

Fall Grass-Eating “Worms”

Fall Grass-Eating “Worms”

Brown patch in grass

Chewing caterpillar damage on St. Augustinegrass Photo by: Steven Arthurs, UF

Tropical sod webworm larvae are destructive pests of warm season turfgrasses in the southeastern U.S. especially in the fall.  Commonly referred to as a worm, they are truly caterpillars, the larvae of a moth. Larval feeding damage reduces turfgrass aesthetics, vigor, photosynthesis and density, which is very evident on finer-bladed grasses such as bermudagrass and zoysiagrass. Feeding damage is possible on all grass types however. Adults, a dull brown colored moth about ¾ inch long, rest in sheltered and shrubby areas during the day and are active at dusk.  Females deposit clusters of 10-35 eggs on the upper surface of grass blades.  The eggs hatch in 3-4 days and develop from a 1 mm long caterpillar to one over 11 mm long through six instars within 21 to 47 days, depending on temperature.  Larval feeding occurs at night, leaving the grass looking ragged, shortened and missing.

Small green caterpillar in grass

Sod webworm on soil surface
Photo by: Steven Arthurs, UF

 

Control should be against damaging larvae, not the flying moths.  However, insecticidal soap applications to moth harboring areas can reduce re-population frequency.  Soil-drenching soap flushes can be used to find the caterpillars, especially in dry and hot grass areas.  Bacterial-based insecticides, such as Bt, Bacillus thuringiensis var. kurstaki or Spinosad, will control sod webworm caterpillars without impacting beneficial species as long as they are applied with each flush of grass growth.

 

Fall armyworms are also active when the weather turns cooler. They feed any time of the day or night, but are most active early in the morning or late in the evening.  The 1 ½ inch long gray and white moth lays about 1,000 eggs in multiple masses on any vegetation.  Two to 10 days later, the small caterpillar hatches and begins to grow to nearly 2 inches long over a two week period.  The fall armyworm is easily recognized by its dark head marked with a distinct pale-colored inverted Y and the long black stripe running along each side of its body.  These aggressive feeders “march” rapidly across grassed areas consuming every above-ground plant part.  While bacterial-based insecticides will reduce the numbers, control of armyworms usually requires synthetic insecticides.

Striped caterpillar with Y marking on the head

Armyworm
Photo by: Jim Castner, UF

 

The good news is that grass “worms” can be controlled and the blades will grow back.  The damage may be devastating to see, but usually not a permanent problem.

Who’s That Piercing My Plants?

Who’s That Piercing My Plants?

There are lots of plant pests out there, and it can take a trained eye to tell which one is doing damage. Many of the insect pests that feed on crops and ornamentals have piercing-sucking mouthparts. These insects do not chew on leaves and leave holes behind; instead, they have a long stylus-like mouthpart they use like a straw to suck out plant juices. Over time this can weaken plants, cause irregular growth as damage builds up on new sprouts, introduce diseases to their hosts, and even cause mold to grow on leaves.

Because they drink so much fluid for their meals, many piercing-sucking insects exude a sugary liquid called honeydew. This liquid drops onto stems and leaves below which can leave them shiny and sticky. Eventually, the coating will grow a light greyish coating of sooty mold, which doesn’t do much harm to the plants itself but is a good indicator that you have an insect problem. You may also notice ants on your plants, working to harvest the honeydew for food. The ants don’t harm the plant, but following are some of the pests that do:

 

Aphids feeding on a plant stem.

A parasitic wasp emerging from a dead aphid.

Aphids – Found on a wide variety of plants, aphids are fat-bodied little insects that often focus on new, tender growth.  Their color depends on the plant they’re feeding on, and they can breed explosively. A female aphid does not need to mate to produce offspring, so a one can produce a lot of children very quickly. Look closely and you might be able to see their cornicles, which look like little tailpipes; these can help identify these pests. Luckily, we have some help in controlling aphids, as they are often parasitized by wasps. If you see large, swollen, brown aphids present, you probably have some wasps working for you.

 

Ants tending some scale insects on a stem.

Scale Insects – Sometimes appearing to just be a bump on a stem or leaf, scale insects don’t move once they pick a plant to live on. Prolific producers of honeydew, some species grow a waxy shell which can protect them and make them difficult to deal with.

A mealybug.

Mealybugs – If you spy something white and fluffy living on stems or leaves, you might have mealybugs. Soft-bodied insects that are related to scales, they don’t move much. They feed on a wide range of host plants, but can effectively be controlled with a variety of methods once they’re found.

Whiteflies on the underside of a leaf.

Whiteflies – Not true flies, they are truly white in color. Tiny little members of the order Hemiptera (the same order that includes, aphids, scales, and mealybugs), they hang around the undersides of leaves. They enjoy warm weather and can become a problem in greenhouses. They are a bit more difficult to control than some of the other pests listed here.

A psyllid nymph hiding in its waxy coating.

Psyllids and planthoppers – Small jumping insects that affect a variety of plant species, some are responsible for transmitting important plant diseases. Pierce’s disease of grapes and citrus greening, for example, are both vectored by these critters. Young nymphs sometimes secrete a waxy coating which may make them look similar to mealybugs.

A tiny two-spotted spider mite.

Spider Mites – Not an insect but an arachnid, spider mites love hot, dry weather. Almost microscopic in size, the damage they do to leaves is often the first sign that they are present. Looking closely, one might notice tiny webbing where the mites live, or even the mites themselves on the undersides of leaves and on stems.

Many of these pests can be treated with a combination of methods. A sharp jet of water can dislodge some, hand removal can reduce populations even more, and products such as insecticidal soap or horticultural oils can finish them off. Insecticidal soaps are best used on soft-bodied insects such as aphids or mealybugs, while oils such as neem can help suffocate hard scales. Use products such as horticultural oil in the evening during hot weather to avoid damaging plant tissues with intense sunlight. Thorough coverage is important, as these products only control the pests they contact.

For more information on controlling insects, see our EDIS publications, such as Insect Management in the Home Garden or Landscape Integrated Pest Management.

Springtailed Invaders

Springtailed Invaders

A month or so ago I was leaving for work and I noticed a strange substance near the entrance to the house.  The substance was blue and my first thought was crushed chalk from my kids writing on the sidewalk.  Upon closer investigation I realized the substance was moving!  It was now clear to me that the substance wasn’t chalk, but a congregation of insects.  Naturally, I took pictures and collected a sample to bring into the county extension office…where I work.  I looked at the insects under the microscope, but I wasn’t able to determine the species.  So I sent some samples off to the University of Florida/IFAS Entomology and Nematology Department and the Florida Department of Agriculture and Consumer Services.

A swarm of Desoria flora

A swarm of Desoria flora on damp, outdoor steps. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

The experts identified the specimens as Desoria flora, a species of springtail insects endemic to Florida and originally described in Alachua County in 1980.  Both entomologists thought it was unique the springtails were swarming.  Springtails live in leaf litter and upper layers of soils.  They are sometimes found in the potting mix of indoor and outdoor plants.  Clients bring springtail specimens in to the office for identification from time to time.  However, this was the first time I had seen them in a congregation.

A linear springtail

A linear springtail. Photo Credit: University of Florida/IFAS

If you find interesting insects, plants, or fungi and want them identified, please bring them into your local Extension Office.  We’d be happy to help you identify the specimens.  But sometimes we have to mail things off to a specialist.