What’s Biting You?
by Jody Green, Extension Educator
A question that comes into the office year round is “What’s biting me?” There are a variety of biting pests that drive us crazy, some require a blood meal to survive, others bite defensively and few appear to irritate us for no reason at all. Not all are technically insects, so we’ll group them into the larger category called arthropods, which include all insects, ticks and mites.
Arthropods That Bite Humans as a Primary Host
Ticks are arachnids, not insects. They are wingless, tough and leathery and always parasitic. Ticks find a host by “questing” from the ground and then move upward to warm areas such as the groin, armpit, behind the ears and on the scalp.
Two of the most prevalent ticks in Nebraska include the American dog tick and the lone star tick. When ticks bite, they embed their barbed mouthparts into the skin and can remain attached to the host for a number of days if undisturbed.
Remove ticks by grasping them as close to the skin as possible with tweezers and pulling straight out. If a tick is removed within 24 hours, there is little risk for disease. Ticks are known to vector diseases such as Rocky Mountain spotted fever, tularemia and ehrlichiosisMosquitoes
Mosquitoes are the deadliest animals on the planet, vectoring disease such as malaria, yellow fever, dengue fever, Chikungunya, Zika virus and West Nile virus. Female mosquitoes lay eggs on the surface of standing water and the larvae require an aquatic environment to develop before pupation. Mosquitoes seem to bite all over the body, and depending on the person, reactions can be insignificant or cause for major discomfort and itching.
Other biting flies have mouthparts that cut through the skin and suck blood from the host. The eggs of flies are laid in the material that the larvae (maggots) develop, which are always associated with semi- or aquatic habitats involving water and moisture. Some biting flies include:
- stable fly,
- biting midge or no-see-um,
- black fly or buffalo gnat,
- horse fly,
- deer fly, and
- sand fly
Females require the blood meal of mammals to produce eggs. Most males feed on plant nectar (except stable fly). Some biting flies can transmit diseases to livestock animals.
Bed bugs are closely associated with human sleeping quarters (usually within an 8-foot radius) as they often bite during the night while we are sleeping. They detect humans by heat and carbon dioxide and require a blood meal to survive. A bed bug infestation is signified by bites, fecal stains, cast skins, eggs and live bugs of all stages. Bed bugs are active all year round since they live where we live. They feed on the exposed skin of sleeping humans, typically not the scalp.
Bed bugs look similar to bat bugs, so it is important to have bed/bat bugs identified by an expert because treatment and prevention methods differ. Bed and bat bugs are not vectors of disease.
Arthropods That Bite Humans in Absence of a Primary Host
Bat bugs look similar to bed bugs, but their primary host are bats.
Mites are closely related to ticks and are wingless arachnids. The mites that irritate humans are tiny, microscopic ones, unseen to the naked eye. Reactions from mites occur hours after exposure as it takes a while for mites to attach and feed. Itching usually lasts about 10 days and bites can persist for two weeks, unless infected. Mites are not vectors of disease.
Itch mites are not blood feeders, but when exposed to humans will feed on tissue. The straw itch mites infest people handling infested grains such as wheat, oats, barley and grass seed. Oak leaf gall mite has affected people in Lincoln periodically since 2004. The oak leaf gall mite is a predator of midge larvae living in growths on the leaves of pin oak trees. When the mites lose their host, they drop down and land on people. Bites usually occur on the upper body: head, neck, shoulders and upper torso.
Chigger mites are the larval form of the red harvest mite; which feeds on other insects and insect eggs as an adult. They do not suck blood, but cut into the skin and digest liquefied cells. Chiggers spend most of their lives in the cracks in the soil and populations in the lawn can be spotty. Chigger bites are usually located on the lower body in clusters where skin is thin, soft and warm, which is why they bite around ankles, knee pits and waist bands where clothing is tight.
Bird mites are ectoparasites of birds. They become a problem when birds nesting in or near the home abandon the nest, leaving the bird mites hungry for a blood meal. They can only live for 10 days and can’t multiply without a bird host. What’s Biting You? Lone star tick female has white spot on dorsum, which is still noticeable when engorged.
Fleas are wingless, hardened, flattened side-to-side insects with specialized jumping legs. The adult fleas live and feed on the host, which is usually the family cat or dog. Homes without pets can get fleas when they are brought in from outdoors. Flea bites on people typically occur on the lower body.
The larvae, which resemble small worms, live deep in the fibers of the carpet, furniture or pet-resting areas. Fleas can remain in a pupal stage for many months in the absence of a host. Emergence is stimulated by vibration, heat and carbon dioxide, which is why vacant summer houses and condos may appear to be infested with fleas upon returning.
Arthropods That Inadvertently Bite Humans
You may ask, “Why? Why would an organism bite humans, if they do not feed on blood?” This is a good question and, unfortunately for us humans, we become the victim of irritating bites from insects that feed on plants or other insects. These insects do not feed on blood, do not inject saliva or venom, and repellents are not effective against them either. The multi-colored Asian lady beetle and minute pirate bug are considered natural enemies and beneficial insects, but they can land on people and bite. Thrips and lace bugs are plant feeders that can also cause irritation to exposed skin. Western flower thrips are attracted to bright colors of flowers and may accidentally land on humans wearing bright colored clothing. Hackberry lace bugs fall out of trees in the late summer and bite people. Control is not practical as irritation is minor and damage to tree is minimal.
How to Prevent Bites
Ticks and fleas are commonly brought in on the family pet or on clothing. Talk to the veterinarian about preventative treatments, groom and brush pets and check yourself, family members and pets immediately after outdoor activity. To protect yourself against mosquitoes, wear long sleeves and long pants, wear permethrin–treated clothing, apply effective repellents (DEET, Picaridin, IR3535, oil of lemon eucalyptus) and limit exposure during periods of high pest activity. To reduce bites from itch mites and chiggers, avoid sitting on grass and walking under infected oak trees, launder clothing and shower immediately after coming in from outdoors.
Frequently Asked Questions
CAN YOU TELL ME WHAT BIT ME? No. It is important to remember that it is very difficult, if not impossible to identify the pest based on a single individual’s reaction. Some people localize symptoms at the location of a bite (swelling, itching, redness), while others suffer systemic reactions which can appear as hives or a rash. These reactions can be immediate or delayed, presenting as a skin irritation or illness 24 hours or weeks after the bite occurred. On the other hand, there is a portion of the population who have no reaction to any bites, including mosquitoes, fleas and bed bugs.
WHAT SHOULD I DO IF I THINK I’VE BEEN BITTEN? Collect the critter that bit you! Bag it up, put it in a container or stick it to a piece of paper so you can get it identified by an expert. If you suffer a bad reaction, doctors can help determine the proper medical care for your situation. Without the specimen or eye witness to the bite, it is impossible to confirm and challenging to prevent future bites. Seek medical attention if symptoms worsen. If you feel as though you are being bitten, but have not found any insects or arthropods, contact a doctor or dermatologist. The root cause for your skin irritation may NOT be arthropod related. Note: There have been a number of scabies cases in Lancaster County, which is a medical issue. Scabies are mites that burrow under the skin and transmitted through person-to-person contact. Scabies causes severe itching and irritation, especially at night. Doctors can perform a skin scraping to confirm scabies and then prescribe treatment.
Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the University of Nebraska–Lincoln is implied. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office