A chigger is the parasitic larval stage of a common mite in the genus Trombicula. Several species of chiggers exsist in the United States, but Trombicular alfreddugesi is most commonly encountered. The adult stage is not parasitic and is often seen in lawns and moving across pavement. They are brilliant red and often are called "red bugs". The adult stage spends it's winter in the soil and the females will deposit eggs during the first warm days of spring. Eggs hatch into chiggers that are only about 1/150th inch in diameter. It is this stage that attacks humans and causes so much discomfort.
Chiggers crawl about on vegetation, waiting to attach to a host. Rodents, birds, livestock, snakes, toads and other animals serve as natural hosts. Humans are an accidental host. There are two to three generations of chiggers produced each year, so the threat of being attacked exists from May until the first killing frost.
In general, chiggers are more common in damp areas with low-growing shrubs, tall grass, weeds, etc. Within favorable habitats, the distribution of chiggers is usually patchy. Individuals are often concentrated in certain areas of the habitat and virtually absent from other areas of apparently equal quality. The unfortunate person sitting in an area with a high concentration of chiggers will be attacked, while someone sitting only a few yards away will often receive no bites at all.
After coming into contact with a human host, chiggers will crawl upward, going under or through clothing until they find an area where clothing fits tightly against the skin. Rather than pass through tight places, they will frequently settle down and begin to feed. They commonly settle and feed in areas such as the tops of shoes and socks, inside tight-fitting underwear under a waistband or bra, at the back of knees and in the crotch and armpits.
Chiggers do not burrow into the skin or suck blood. Instead they pierce the skin with their mouth parts and inject a digestive enzyme. This fluid dissolves the tissues of the host, which are then sucked up by the chigger as food. Within a few hours, tissue around the feeding area solidifies into a hardened tube, called a stylostome. The chigger remains attached to the stylostome and sucks up liquefied tissue-like a person drinking through a straw. Feeding will continue for three or four days if left undisturbed. Itching usually starts within hours and the chiggers are often scratched away before they finish feeding.
Chiggers quickly die if they are dislodged from the host, but the irritation and resulting itch from the bite will continue until the body neutralizes the saliva, dissolves the stylostome and repairs the tissue damage, The dissolved tissue will continue to ooze out of the wound each time it is scratched. The fluid that oozes from the wound solidifies into a hard "cap." This cap
is a distinct feature of chigger bites and is not associated with other arthropod bites such as mosquitoes.
The best defense against chiggers is to avoid them. Avoid wearing shorts, sleeveless shirts and sandals when going onto chigger habitats. Tightly woven fabrics reduce the threat of chiggers penetrating through clothing. Tuck pant legs inside boots, button cuffs and collars tightly to keep chiggers outside of clothing. This increases the time chiggers are exposed to any repellents you have put there. Remove clothing as soon as possible after exposure to chigger habitats and launder it before wearing it again. A warm shower with a vigorous skin massage, taken within an hour or two after exposure greatly reduces the number of irritating bites. However, if itching has already started, it probably is too late for bathing to do much good.
If you must enter chigger infested areas, chemical repellents can be used with good results. Any insect repellent containing DEET (diethyl toulanide) will be effective. It should be applied to clothing from the feet up and must be repeated every two to three hours to maintain its effectiveness, Sulfur powder is also effective when applied to the clothing but has a strong odor that makes it less desirable. Another repellent is Permanone (also sold as Coulston's Permethrin Tick Repellent) It contains the pyrethroid insectaside permethrin and should be sprayed on clothing and allowed to dry before the clothing is worn, These products are generally available at sporting goods stores ans outdoor clothing outlets.
Mowing of lawns and removing unnecessary shrubs or weeds will reduce suitable chigger habitats and is the most effective form of area control. Controlling chigger populations by spraying infected areas has limited effectiveness. However, you can spray, dust or apply a granular pesticide if you have a chigger problem in unkempt areas around your lawn. It is common to treat a 20 foot wide band as a buffer zone. There are several products labeled for chigger control including carbaryl (Servin), chlorpyrfos (Dursban), diazinon or carbaryl (Tempo). Such treatments give temporary control of only a few days or weeks depending on environmental conditions.
By Richard M. Houseman and Bruce A Barrett
Department of Entomology
University of Missouri-Columbia
The brown recluse spider is one of several poisonous spiders in the United States whose bite can cause a severe reaction. This spider can become a problem not only for homeowners but also for pest control operators doing inspections or providing other services in crawl spaces, basements, attics and outbuildings. this spider can be difficult to control without a thorough understanding of its habits.
The brown recluse spider is a native species and is on of several similar-looking fiddleback, violin or brown spiders in the genus Loxosceles found in the United States. The brown recluse is a medium-sized, soft-bodies spider 1/4 to 1/2 inch long with leg span about the size of a half dollar. The males are slightly smaller than the females. The brown recluse is yellowish tan to brown with no obvious pattern, while the base of the legs are yellow-orange in color. Although the legs are covered with very minute brown hairs, they appear bare to the naked eye. Each foot has two claws. The legs of the adult are 1 inch or more and gradually taper. The third pair of legs is the shortest.
The brown recluse spider spins small, loose, white to off-white webs with irregular strands without a definite pattern. It can be a “cobweb-type” webbing, which is used primarily as a retreat for the spider rather than a trap for prey. Indoors, the web can be somewhat flattened and is usually found against a wall or ceiling in an undisturbed corn of a room. Outdoors, the brown recluse spider spins a tube or cocoon like web of thick silk for the winter.
The brown recluse feeds on a wide variety of small insects. It is active primarily at night and will stalk prey in the open. During the day, it hides in dark niches and corners, hence its name. Cockroaches and other household insect pests can readily sustain spider infestations indoors. The brown recluse can survive long periods without food.
The female lays eggs from May through August in sacs containing 40 or more eggs, which she guards until she dies. A female will bear as many as 300 eggs during her lifetime. These spiders mature in about 11 months and may live as long as two years.
The brown recluse is found mainly in the Midwestern and Southern states, but has been spreading into the Middle Atlantic states. This spider is a serious problem in Oklahoma, Missouri, Arkansas and Kansas and in parts of the surrounding states. It has also been reported in California, Wyoming, Arizona, Florida, Washington, D.C., and in other locations. However, it should be remembered that a complex of fiddleback spiders can be found in these areas that can be easily confused with the more dangerous brown recluse.
Brown Recluse’s Bite
Both the female and the male brown recluse have the ability to bite and inject venom. The brown recluse is not aggressive and usually retreats from situations that may be threatening. However, it usually bites when it is disturbed or is being crushed.
Most bites occur on the hands and arms when people put on clothing that has been stored or when they roll over in bed. The bite is usually not felt but may cause a stinging sensation. The victim may not be aware of the bite for one to three hours. This is followed by a small blister, local swelling and mild to severe pain to to eight hours later.
The person who is bitten may become restless, feverish and have difficulty sleeping. The local pain is frequently quite intense, and the area surrounding the bite remains congested and hard to the touch for t some time. The tissue affected locally by the venom is killed and gradually sloughs away, exposing underlying muscles. The edges of the wound thicken and are raised, while the central area is filled by dense scar tissue. Healing takes place quite slowly and may take six to eight weeks. The end result is a sunken scar, which has be described as resembling a "hole punched or scooped from the body". Scars ranging from the size of a penny to half-dollar have been reported.
The necrotic condition described above is typical of all bites of the brown recluse. However, in some cases, a general systemic reaction has also occurred. In one case, the person who was bitten broke out with a rash resembling that of scarlet fever. In another case, the kidneys were apparently affected, causing bloody urine to be passed. These systemic disturbances probably occur infrequently and are the result of a "full" bite (i.e., the injection of a maximum amount of venom) or extreme sensitivity to the venom. The general reaction to the bite of the brown recluse is certainly a serious condition, and hospitalization of the patient may be required. Those in poor general physical condition, young children and older people are ore apt to be affected seriously by the bite of the brown recluse.
If bitten by a brown recluse spider, first make a positive identification, if possible, and then clean the site of the spider bite well with soap and water. If the spider bite is on an arm or a leg, tie a snug bandage above the bite to help slow or halt the spread of venom. Ensure that the bandage is not so tight as to cut off circulation in the arm of the leg. Use a cold colth at the spider bite location. Apply a cloth dampened with cold water or filled with ice. Seek immediate medical attention. doctors may treat a brown recluse spider bite with corticosteroids.
Spider Bite Prevention
Recognizing the spider, and knowing it is poisonous, should reduce the chance of contact.Examine and shake out clothing that has hung unused for a long time in closets and other storage unused for a long time in closets and other storage areas before wearing. Boots that have not been worn for some time are a favorite hiding place. Be cautious when you clean storage areas. Places suspected of harboring spiders may be treated with insecticides. Reducing insects around infested areas is an
important factor in spider control, as the insects serve as food for the spiders.
The brown recluse should be controlled in the spring and early summer since the spiders move about in the late summer and fall months. This tendency to wander may be due to efforts of the sexes to locate one another for mating. Most of the bites experienced by humans occur from June to October.
Effective spider control requires good sanitation and elimination of insect prey as well as chemical treatment. The following spider management program is suggested:
Biology and Control of Spiders, Scorpions, Centipedes and Millipedes FSA7018
John Hopkins Associate Professor and Extension Entomologist
Gus Lorenz Associate Department Head, Distinguished Professor, Extension Entomologist and IPM Coordinator
Glenn Studebaker Associate Professor and Extension Entomologist
Kelly Loftin Associate Professor and Extension Entomologist
The recent huge rains in much of the country have brought the ants out in big numbers, fire ants and many other species. Odorous ants are a common household problem in Arkansas. Odorous ants are1/8 of an inch long and brown to black in color. When crushed they give off an odor that smells like rotten coconut or pine scent. They will nest anywhere there is food and moisture and can be difficult to control. Finding the nest is important in the control, below are some tips that will help.
1. Do some research and identify what ant species you are dealing with. Each species has different habits and locating their food, water and shelter will determine your success.
2. Watch the activities of the ants to find where they are coming and going. If you find how they are entering your home, you can physically exclude them.
3. Remove or alter the conditions that invited them in the first place. Keep counters clean of food. Try to keep sinks and surrounding areas dry. Wiping counters down with vinegar or citrus oil can work as a temporary deterrent as well as increase the cleaning power.
4. If steps 1-3 do not slow the ants down, it is time for baits, dusts or sprays. Remember that you are only seeing a small portion of the colony at any one time. Only about 10% of a colony will forage outside the nest. Therefore baits are often the most effective approach. Applying any insecticide organic or chemical will not work to solve an ant infestation in the long run. It could cause the colony to bud or split into multiple colonies creating more problems.
5. Properly made baits are highly attractive to ants and under most conditions provide good control. Place baits into spill proof containers out of the reach of children and pets. The stations will need to be placed along active ant trails. It is important to remember that boric acid contains elemental boron and at high concentrations will sterilize soil. This process is slow and requires monitoring and refilling of the bait stations.
6. Ants have a habit of changing food sources from sugars to carbohydrates. It may become necessary to mix peanut butter with boric acid to supply both forms of bait to keep the ants feeding on the boric acid.
7. There are ant baits with the active ingredient abamectin. These baits can provide good control and should be used for heavy infestations or when other bait is not effective. They can be applied in stations around foraging ants or broadcast around ant trails. Again, boric can be damaging to the soil.
9. If the homemade baits fail or if you’re not the “home brew” type, hiring a professional pest control company would be the next step.
Howard Garrett, The Dirt Doctor Newsletter
Pest Management News, University of Arkansas, Agriculture System, May 31st 2015, by John D. Hopkins
Bagworms on arborvitae and juniper are active this time of year, and doing some serious damage. They also attack pine, spruce, cypress, black locust, willow, sycamore, apple, maple, elm, poplar, oak, and birch. They attack the buds of conifers causing tip dieback and open dead areas.
Extensive defoliation may occur followed by the death of the plant. They have one generation a year and over-winter as eggs in the female bag. There can be as many as 300-1000 eggs in a single bag. Hatching occurs in May-June depending on weather. When the larvae hatch they leave the bag, spinning down from it by a strand of silk that often acts like a parachute to carry them to new hosts. There they immediately spin themselves a bag, which becomes covered with plant debris from the host as they crawl around feeding. This camouflages them so well that they often go unnoticed until considerable damage has been done. In fact many homeowners fail to notice them until they have matured and permanently glued themselves to a stem. At that point they have quit feeding and the damage has been done for the year.
The first line of defense is hand picking and destroying the bags. Be sure to remove the silk that binds the bag to the stem as it may cause girdling later. A biological control that works well is BT (Bacillus thuringiensis). This product only kills caterpillars. It will not harm beneficial insects.
More Chemical Control Options:
Department of Plant Pathology - Plant Health Clinic News
Baxter County Extension Office
LONOKE — Residents throughout the eastern half of Arkansas are likely already hearing the creeping call of Brood XXIII, the cluster of cicada species emerging from a 13-year slumber to frenetically mate for the next three to four weeks before disappearing for another 13 years beneath the soil.
Gus Lorenz, extension entomologist for the University of Arkansas System Division of Agriculture in Lonoke, said that early May typically brings soil temperatures at a depth of 7-8 inches — where cicadas live most of their lives — just right for the insects emergence. Brood XXIII, also known as the Lower Mississippi Brood, involves four species of cicada, and is geographically associated with eastern Arkansas, northeastern Louisiana, most of Mississippi, western Tennessee, southeastern Missouri and the southern portions of Illinois and Indiana.
Most of cicadas’ existence takes place in wooded areas, making their chorus much more noticeable to people living in rural, wooded areas or at the edge of urban areas. As nymphs in the soil, the insects draw nutrients from the roots of plants or trees. During an emergence, male cicadas emerge first, forming “chorus centers,” which in turn attracts females.
Lorenz said the females use a saw like “ovipositor” to lay their fertilized eggs into the limbs of a tree. When the eggs reach the larval stage in August, they fall to the ground and burrow into the soil, and begin the years-long process again.
Not all cicadas are on a 13-year cycle, Lorenz said. Some species, such as the Dog Day Cicada, emerge in Arkansas each August. Others are on two- or four-year cycles.
The most curious of the broods, however, are on 13- or 17-year emergence cycles. Kimberly Smith, a professor of biological sciences at the University of Arkansas in Fayetteville, said 30 broods — 13 13-year broods and 17 17-year broods — were identified by Charles Lester Marlatt in 1907.
“He wrote the book on periodic cicadas more than 100 years ago, and it’s still sort of the bible on the insects,” Smith said. He said some researchers consider Marlatt’s identification of 30 broods arbitrary, and than some broods have since disappeared.
“Today, there are only three 13-year broods left, and about 12 of the 17-year broods,” Smith said.” So some of the broods have gone extinct. Some of the broods were really small, and there’s some question as to whether some of them were really ‘a year’ by themselves. It seems pretty clear that Marlatt wanted 30 broods.”
Smith said that two key mysteries still tied to cicadas. The first is a question of how the millions of insects in a brood that spans hundreds of miles all know to emerge at essentially the same time. He said it may be time to a chemical associated with the roots from which the cicadas draw their nutrients, but that there may also be an unexplained element of communication between the insects.
The second mystery is how or why many of the broods operate on 13- or 17-year cycles — a reliance on prime numbers unique in the natural world. Smith said whatever the reason, it has helped the insects survive.
“A lot has been made of the fact that 13 and 17 are prime numbers, and that predators can’t wait for them,” Smith said. “If they were on a 12-year cycles, there’d be predators on a six-year cycle that would catch them every other time. Predators on a four-year cycle would catch them every third time, and so on. But on a 13- or 17-year cycle, there’s no way a predator could actually stay with them.”
The sheer numbers of near-simultaneously emerging cicadas — sometimes calculated at more than 1 million per acre — is another avenue of survival and species perpetuation, Lorenz said.
“It’s a method of self-preservation,” Lorenz said. “Some insects protect themselves by stinging, or with camouflage. Some of them lay thousands of eggs. In the case of the cicada, by all of them coming out at the same time, there are too many there for predators to eat them all.”
Lorenz said that doesn’t stop the rest of the natural world from trying.
“These things are pretty tasty to wildlife.,” he said. “Birds, coons, possums, all kinds of rodents. We’ve seen in past emergences where they come out in such huge numbers, birds eat so many that they can’t even fly away.
“It’s a boon for wildlife. When this emergence occurs, it’s a really positive thing,” he said.
Smith added that the cicadas “are pretty good fish bait until the fish become satiated. Even copperhead snakes are attracted to the emergence.”
Smith said the phenomenon is described as “predator swamping” or “predator satiation.”
Lorenz and Smith said that although the insects — which should not be confused with locusts — will occasionally make their way into cotton or other crops if they’re planted near the edge of a heavily wooded area, they don’t constitute enough of a pest to warrant pesticide treatment. Smith said cicadas are often despised by peach growers, however, because the weight of cicada eggs at the ends of tree branches can cause leaves to brown and the ends of the branches to “flag” and droop or break off.
By Ryan McGeeney
The Cooperative Extension Service
U of A System Division of Agriculture
Media Contact: Mary Hightower,
Dir. of Communication Services
U of A Division of Agriculture
Cooperative Extension Service
Arkansas Agriculture Department/Arkansas State Plant Board officials today confirmed that the emerald ash borer (EAB), an invasive beetle that attacks and kills ash trees, has been found in Hot Springs, Clark, and Nevada counties.
Beginning in 2009 the Arkansas State Plant Board and the United States Department of Agriculture, Animal Plant Health Inspection Service, Plant Protection and Quarantine (USDA APHIS PPQ), through a cooperative program, have conducted an Emerald Ash Borer survey. The survey has been ongoing with USDA APHIS PPQ surveying approximately one half of the state and the Arkansas State Plant Board surveying the remaining counties. The survey consists of placing traps and inspecting Ash trees for signs of EAB infestations.
Emerald Ash Borers have been detected in traps placed in Hot Springs, Clark, and Nevada counties. The insect specimens from the Hot Springs and Clark county traps were sent to scientists at USDA APHIS PPQ, who have confirmed the insect’s identity. The insects trapped in Nevada County have been screened by an Arkansas State Plant Board entomologist and are considered highly likely, however official confirmation will be made by USDA APHIS PPQ scientists.
EAB is now present in 24 U.S. states and two Canadian provinces. It was first discovered in Michigan in 2002 and has since killed tens of millions of trees.
The adult emerald ash borer is a metallic green insect about one-half inch long and one-eighth inch wide making it hard to detect in the wild. The female beetles lay eggs on the bark of ash trees. The eggs hatch and the larvae bore into the bark to the fluid-conducting vessels underneath. The larvae feed and develop, cutting off the flow of nutrients and, eventually killing the tree. EAB attacks and kills North American species of true ash, and tree death occurs three to five years following initial infestation. EAB is native to Asia.
Signs of EAB include: canopy die back beginning at the top of the tree and progressing through the year until the tree is bare; sprouts growing from the roots and trunk; split bark with an S-shape gallery; D-shaped exit holes; and more woodpecker activity, creating large holes as they extract the larvae.
State and USDA APHIS PPQ personnel will now survey trees in the areas surrounding the initial finds to determine the extent of the EAB infestation. It is expected that a federal quarantine will be expanded to include parts of Arkansas and potentially the entire state.
To prevent the spread of this beetle, do not move firewood. Firewood is a vehicle for movement of tree-killing forest pests including EAB and Asian long-horned beetle. Use locally-sourced firewood when burning it at home. When traveling, burn firewood where you buy it. Make sure to burn all wood purchased.
Report signs of the beetle to the Arkansas State Plant Board
Contact: Scott Bray
For more information about Emerald Ash Borer, visit:
Baxter County Master Gardener Program • University of Arkansas System • Division of Agriculture • © 2013 BCMG