Trombiculidae
Encyclopedia
Trombiculidae is a family of mite
s called trombiculid mites (also called berry bugs; harvest mites; red bugs; scrub-itch mites; and aoutas. In their larva
l stage, those species which bite their host and "causes intense irritation
" or "a wheal
, usually with severe itching and dermatitis
," are called chiggers. The term chigger is often confused with the term jigger, the Chigoe flea
. Trombiculidae live in the forests and grasslands and are also found in low, damp areas where vegetation is rank such as woodland
s, berry bush
es, orchard
s, along lakes and streams, and even in drier places where vegetation is low such as lawn
s, golf course
s, and park
s.
They are most numerous in early summer when grass, weeds and other vegetation are heaviest. In their larval stage they attach to various animals, including humans, and feed on skin, often causing itching. These relatives of tick
s are nearly microscopic measuring 0.4 mm (1/60 of an inch) and have a chrome-orange hue. The (best known) species of chigger in Northern America is the hard-biting Trombicula alfreddugesi
of the south-eastern United States and humid mid-west and Mexico; in the UK the most prevalent chigger is called the "harvest mite," the Trombicula autumnalis
, with distribution through Western Europe to Eastern Asia, but is not found in North America nor Australia.
Trombiculid mites go through a life cycle of eggs
, larva
, nymph
, and adult
. The larval mites feed on the skin
cell
s, but not blood
, of animal
s, including human
s. The six-legged parasitic larva
feeds on a large variety of creatures including human
s, rabbit
s, toad
s, box turtle
s, quail
, and even some insect
s. After crawling onto their host
, they inject digestive enzymes into the skin that break down skin cells. They do not actually "bite," but instead form a hole in the skin called a stylostome and chew up tiny parts of the inner skin, thus causing severe irritation and swelling. The severe itching is accompanied by red pimple-like
bumps (papule
s) or hives and skin rash or lesions on a sun-exposed area. For humans, itching usually occurs after the larvae detach from the skin.
After feeding on their hosts, the larvae drop to the ground and become nymphs, then mature into adults which have 8 legs and are harmless to humans. In the post larval stage, they are not parasitic and feed on plant materials. The females lay 3–8 eggs in a clutch, usually on a leaf or under the roots of a plant, and die by autumn.
τρομειν ("to tremble") and Latin culex, gen. culicis ("gnat" or "midge"), was first described as an independent family by H.E. Ewing in 1944. Then, when the family was first described, it included two subfamilies, Hemitrombiculinae and Trombiculinae. Womersley added another, Leeuwenhoekiinae, which at the time only contained Leeuwenhoekia (Oudemans, 1911). Later he erected the family Leeuwenhoekiidae for the genus and subfamily, having six genera; they have a pair of submedian seta
e present on the dorsal plate.
References to chiggers, however, go as far back as sixth century China, and by 1733, the first recognization of trombiculid mites in North America were made. In 1758, Linnaeus described a single species Acarus batatas (Now Trombicula batatas). However, most information about chiggers came from problems that arose during and after World War II.
, harvest mites are called aoûtat, or "August" flies). In the United States
, they are found mostly in the southeast, the south, and the Midwest
. They are not present, or barely found, in far northern areas, in high mountains and in deserts. In the British Isles
, the species Trombicula autumnalis
are called harvest mites, in North America
the species Trombicula alfreddugesi
, and the species Trombicula (eutrombicula) hirsti
which are found in Australia
and are commonly called the scrub-itch mite.
The length of the mite's cycle depends on species and environment, but normally last 2 to 12 months (but may be longer). The number of cycles in a year depends on the region. For example, in a temperate region, there might only be 3 a year, but in tropical regions, the cycle might be continuous all year long. Adult harvest mites scuttle off yonder over winter to protected places such as slightly below the soil. Females become active in the spring, and once the ground temperature is regularly above 60 °F (15.6 °C), she lays eggs, up to 15 eggs per day in vegetation when soil temperatures are 60 °F (15.6 °C). Therefore, from April through early autumn up until the first frost, humans are susceptible to chigger bites.
The larvae congregate in groups on small clods of earth, in matted vegetation and even on low bushes and plants, where they have more access to a prospective host. The eggs are dormant for about six days, after which the non-feeding pre-larvae emerge, with only three pairs of legs. After about six days, the pre-larva grows into its larval stage.
and adult stage. The eggs are round in shape.Chigger is also an alternate term for the chigoe flea
(Tunga penetrans), a sand flea found in tropical and subtropical climates in the Americas and Africa
.
The name chigger originated as a corruption of chigoe. Also called scrub mite, red mite and several other names, they are found throughout temperate and tropical zones. Chiggers come in 3 stages: the deutovum, unfed larva, and engorged larva. Once in the egg developing, the larvae enclosed in a membrane in addition to the eggshell, are called deutovum. After hatching, the unfed larvae migrate to the highest area and wait for a host.
The larval stage is the only parasitic stage of the mite's life cycle. They are parasites to many animals. About 30 of the many species in this family, in their larval stage, attach to various animals, including amphibians, reptiles, birds, and mammals, and feed on skin. This often causes an intensely itchy red bump in humans (who are accidental hosts).
Chiggers attach to the host, pierce the skin, inject enzymes into the bite wound that digest cellular contents, and then suck up the digested tissue through a tube formed by hardened skin cells called a stylostome. They do not burrow into the skin or suck blood, as is commonly assumed. Itching from a chigger bite may not develop until 24–48 hours after the bite, so the victim may not associate the specific exposure with the bite itself. The red welt/bump on the skin is not where a chigger laid eggs, as is sometimes believed. The larva remains attached to a suitable host for 3 to 5 days before dropping off to begin its nymph stage.
Chiggers do not like sunlight or humidity. Note, however, that there appears to be some disagreement here, since many other authorities state that chiggers thrive in and need high humidity. During the wet season, chiggers are usually found in tall grass and other vegetation. During dry seasons, chiggers are mostly found underneath brush and shady areas.
are considered a dangerous pest in East Asia
and the South Pacific
because they often carry Orientia tsutsugamushi
, the tiny bacterium that causes scrub typhus
, which is known alternatively as the Japanese river disease, scrub disease, or tsutsugamushi. The mites are infected by the Rickettsia passed down from parent to offspring before eggs are laid in a process called transovarial transmission
. Symptoms of scrub typhus in humans include fever, headache, muscle pain, cough, and gastrointestinal symptoms.
Itching can be alleviated through use of over-the-counter topical corticosteroids and antihistamines. Hot showers or baths also will help reduce itching. In cases of severe dermatitis or secondary infection associated with chigger bites, a doctor should be consulted.
There are dozens of methods for treating chigger bites:
Among the most popular and effective treatments all involve a hot shower or bath accompanied with vigorous scrubbing using cloth and (harsh) soap or typically one of various (drying) antiseptics such as bleach or alcohol as soon as possible.
For quick relief of the itching, splashing on Listerine mouth wash is among the most popular. Also popular is ammonia or Windex. Many others claim relief from various common insect bite or sting remedies.
There is an active debate over the efficacy of the popular remedy: sealing the bite with (clear) nail polish, which typically creates intense itching, often with the plastic film forming a quick, expanding "water blister." People who have experienced this claim that within an hour or so, the itching is gone and the wound will quickly heal. The other side typically argues something like: "Nail polish cannot "smother" the chigger because it has not burrowed into your skin, and it was probably scratched off long ago."
That argument depends on the assumption that the polish supposedly killed a (burrowing) chigger, and if it didn't, the method must be a myth. It does not address the possibility that another mechanism, such as sealing the bite from air, or
removing or neutralizing the stylostome and toxic enzymes otherwise known to remain embedded in the skin for over a week, might be at work.
This stage consists of three phases; the protonymph, deutonymph, and tritonymph, respectively. The protonymph and tritonymph morphology are unusual in species of Trombiculidae. The protonymph phase combines larval and protonymph characteristics with deutonymph and tritonymph morphology. The protonymph is an inactive transitional stage. The active deutonymph develops an additional pair of legs (for a total of eight). Lastly, it re-enters inactivity during its transitional tritonymph phase before growing to adulthood.
Mite
Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology.-Diversity and systematics:...
s called trombiculid mites (also called berry bugs; harvest mites; red bugs; scrub-itch mites; and aoutas. In their larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
l stage, those species which bite their host and "causes intense irritation
Irritation
Irritation or exacerbation, in biology and physiology, is a state of inflammation or painful reaction to allergy or cell-lining damage. A stimulus or agent which induces the state of irritation is an irritant...
" or "a wheal
Wheal
Wheal may refer to:*Wheal response, a cutaneous condition left by a blow or as part of an allergic reaction*Wheal, a Cornish mine...
, usually with severe itching and dermatitis
Dermatitis
-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...
," are called chiggers. The term chigger is often confused with the term jigger, the Chigoe flea
Chigoe flea
The chigoe flea or jigger is a parasitic arthropod found in most tropical and sub-tropical climates, not to be confused with the larval form of Trombiculidae found in more temperate climates. In Brazil, the parasite is referred to as bicho-de-pé . At 1 mm long, the chigoe flea is the smallest...
. Trombiculidae live in the forests and grasslands and are also found in low, damp areas where vegetation is rank such as woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
s, berry bush
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
es, orchard
Orchard
An orchard is an intentional planting of trees or shrubs that is maintained for food production. Orchards comprise fruit or nut-producing trees which are grown for commercial production. Orchards are also sometimes a feature of large gardens, where they serve an aesthetic as well as a productive...
s, along lakes and streams, and even in drier places where vegetation is low such as lawn
Lawn
A lawn is an area of aesthetic and recreational land planted with grasses or other durable plants, which usually are maintained at a low and consistent height. Low ornamental meadows in natural landscaping styles are a contemporary option of a lawn...
s, golf course
Golf course
A golf course comprises a series of holes, each consisting of a teeing ground, fairway, rough and other hazards, and a green with a flagstick and cup, all designed for the game of golf. A standard round of golf consists of playing 18 holes, thus most golf courses have this number of holes...
s, and park
Park
A park is a protected area, in its natural or semi-natural state, or planted, and set aside for human recreation and enjoyment, or for the protection of wildlife or natural habitats. It may consist of rocks, soil, water, flora and fauna and grass areas. Many parks are legally protected by...
s.
They are most numerous in early summer when grass, weeds and other vegetation are heaviest. In their larval stage they attach to various animals, including humans, and feed on skin, often causing itching. These relatives of tick
Tick
Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...
s are nearly microscopic measuring 0.4 mm (1/60 of an inch) and have a chrome-orange hue. The (best known) species of chigger in Northern America is the hard-biting Trombicula alfreddugesi
Trombicula alfreddugesi
Trombicula alfreddugesi also called Eutrombicula alfreddugè or E. alfreddugè, is a species in the genus Trombicula....
of the south-eastern United States and humid mid-west and Mexico; in the UK the most prevalent chigger is called the "harvest mite," the Trombicula autumnalis
Trombicula autumnalis
The harvest mite, Trombicula autumnalis, is a species of mite of the family Trombiculidae. Their larvae live parasitically; they infect all domestic mammals, humans, and some ground-nesting birds.-Description:...
, with distribution through Western Europe to Eastern Asia, but is not found in North America nor Australia.
Trombiculid mites go through a life cycle of eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
, larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
, nymph
Nymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a...
, and adult
Adult
An adult is a human being or living organism that is of relatively mature age, typically associated with sexual maturity and the attainment of reproductive age....
. The larval mites feed on the skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
s, but not blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
, of animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s, including human
Human
Humans are the only living species in the Homo genus...
s. The six-legged parasitic larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
feeds on a large variety of creatures including human
Human
Humans are the only living species in the Homo genus...
s, rabbit
Rabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s, toad
Toad
A toad is any of a number of species of amphibians in the order Anura characterized by dry, leathery skin , short legs, and snoat-like parotoid glands...
s, box turtle
Box turtle
The box turtle , or box tortoise is a genus of turtle native to North America . The 12 taxa which are distinguished in the genus are distributed over four species. It is largely characterized by having a domed shell, which is hinged at the bottom, allowing the animal to close its shell tightly to...
s, quail
Quail
Quail is a collective name for several genera of mid-sized birds generally considered in the order Galliformes. Old World quail are found in the family Phasianidae, while New World quail are found in the family Odontophoridae...
, and even some insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s. After crawling onto their host
Host (biology)
In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...
, they inject digestive enzymes into the skin that break down skin cells. They do not actually "bite," but instead form a hole in the skin called a stylostome and chew up tiny parts of the inner skin, thus causing severe irritation and swelling. The severe itching is accompanied by red pimple-like
Pimple
A pimple, zit or spot is a kind of acne, and one of the many results of excess oil getting trapped in the pores. Some of the varieties are pustules or papules....
bumps (papule
Papule
A papule is a circumscribed, solid elevation of skin with no visible fluid, varying in size from a pinhead to 1 cm.With regard to the quote "...varying in size from a pinhead to 1cm," depending on which text is referenced, some authors state the cutoff between a papule and a plaque as 0.5cm,...
s) or hives and skin rash or lesions on a sun-exposed area. For humans, itching usually occurs after the larvae detach from the skin.
After feeding on their hosts, the larvae drop to the ground and become nymphs, then mature into adults which have 8 legs and are harmless to humans. In the post larval stage, they are not parasitic and feed on plant materials. The females lay 3–8 eggs in a clutch, usually on a leaf or under the roots of a plant, and die by autumn.
History
Trombiculidae, from GreekGreek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
τρομειν ("to tremble") and Latin culex, gen. culicis ("gnat" or "midge"), was first described as an independent family by H.E. Ewing in 1944. Then, when the family was first described, it included two subfamilies, Hemitrombiculinae and Trombiculinae. Womersley added another, Leeuwenhoekiinae, which at the time only contained Leeuwenhoekia (Oudemans, 1911). Later he erected the family Leeuwenhoekiidae for the genus and subfamily, having six genera; they have a pair of submedian seta
Seta
Seta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....
e present on the dorsal plate.
References to chiggers, however, go as far back as sixth century China, and by 1733, the first recognization of trombiculid mites in North America were made. In 1758, Linnaeus described a single species Acarus batatas (Now Trombicula batatas). However, most information about chiggers came from problems that arose during and after World War II.
Distribution
Trombiculid mites are found throughout the world. In Europe and North America, they tend to be more prevalent in the hot and humid parts. In the more temperate regions, they are found only in the summer (in FrenchFrench language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...
, harvest mites are called aoûtat, or "August" flies). In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, they are found mostly in the southeast, the south, and the Midwest
Midwestern United States
The Midwestern United States is one of the four U.S. geographic regions defined by the United States Census Bureau, providing an official definition of the American Midwest....
. They are not present, or barely found, in far northern areas, in high mountains and in deserts. In the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
, the species Trombicula autumnalis
Trombicula autumnalis
The harvest mite, Trombicula autumnalis, is a species of mite of the family Trombiculidae. Their larvae live parasitically; they infect all domestic mammals, humans, and some ground-nesting birds.-Description:...
are called harvest mites, in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
the species Trombicula alfreddugesi
Trombicula alfreddugesi
Trombicula alfreddugesi also called Eutrombicula alfreddugè or E. alfreddugè, is a species in the genus Trombicula....
, and the species Trombicula (eutrombicula) hirsti
Trombicula hirsti
Trombicula hirsti is a species in the genus Trombicula, commonly called the scrub-itch mite, it is found in Australia, though more common in the north, because they prefer warmer climate....
which are found in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and are commonly called the scrub-itch mite.
Life cycle
The larvae congregate in groups on small clods of earth, in matted vegetation and even on low bushes and plants, where they have more access to a prospective host. The eggs are dormant for about six days, after which the non-feeding pre-larvae emerge, with only three pairs of legs. After about six days, the pre-larva grows into its larval stage.
Larva
The larvae, commonly called chiggers, are about 0.17–0.21 mm (0.00669291338582677–0.00826771653543307 in) in diameter, normally light red, covered in hairs, and move quickly relative to size. There is a marked constriction in the front part of the body in the nymphNymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a...
and adult stage. The eggs are round in shape.Chigger is also an alternate term for the chigoe flea
Chigoe flea
The chigoe flea or jigger is a parasitic arthropod found in most tropical and sub-tropical climates, not to be confused with the larval form of Trombiculidae found in more temperate climates. In Brazil, the parasite is referred to as bicho-de-pé . At 1 mm long, the chigoe flea is the smallest...
(Tunga penetrans), a sand flea found in tropical and subtropical climates in the Americas and Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
.
The name chigger originated as a corruption of chigoe. Also called scrub mite, red mite and several other names, they are found throughout temperate and tropical zones. Chiggers come in 3 stages: the deutovum, unfed larva, and engorged larva. Once in the egg developing, the larvae enclosed in a membrane in addition to the eggshell, are called deutovum. After hatching, the unfed larvae migrate to the highest area and wait for a host.
The larval stage is the only parasitic stage of the mite's life cycle. They are parasites to many animals. About 30 of the many species in this family, in their larval stage, attach to various animals, including amphibians, reptiles, birds, and mammals, and feed on skin. This often causes an intensely itchy red bump in humans (who are accidental hosts).
Chiggers do not like sunlight or humidity. Note, however, that there appears to be some disagreement here, since many other authorities state that chiggers thrive in and need high humidity. During the wet season, chiggers are usually found in tall grass and other vegetation. During dry seasons, chiggers are mostly found underneath brush and shady areas.
Chiggers as disease vectors
Although the harvest mite chigger usually does not carry diseases in North American temperate climates, the Leptotrombidium delienseLeptotrombidium deliense
Leptotrombidium deliense is a species of mite.It is a vector of scrub typhus....
are considered a dangerous pest in East Asia
East Asia
East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...
and the South Pacific
Oceania
Oceania is a region centered on the islands of the tropical Pacific Ocean. Conceptions of what constitutes Oceania range from the coral atolls and volcanic islands of the South Pacific to the entire insular region between Asia and the Americas, including Australasia and the Malay Archipelago...
because they often carry Orientia tsutsugamushi
Orientia tsutsugamushi
Orientia tsutsugamushi is the causative organism of scrub typhus, and the natural vector and reservoir is probably trombiculid mites ....
, the tiny bacterium that causes scrub typhus
Scrub typhus
Scrub typhus or Bush typhus is a form of typhus caused by Orientia tsutsugamushi first isolated and identified in 1930 in Japan., accessdate: 16 October 2011...
, which is known alternatively as the Japanese river disease, scrub disease, or tsutsugamushi. The mites are infected by the Rickettsia passed down from parent to offspring before eggs are laid in a process called transovarial transmission
Transovarial transmission
Transovarian transmission occurs in certain arthropod vectors as they transmit disease-causing bacteria from parent arthropod to offspring arthropod. For instance, Rickettsia rickettsii, carried within ticks, is passed on from parent to offspring tick by transovarial transmission...
. Symptoms of scrub typhus in humans include fever, headache, muscle pain, cough, and gastrointestinal symptoms.
Handling Chigger Bites
Because chigger wounds are a complex combination of enzymatic and the resulting mechanical damage, plus allergy and immune responses, plus possible secondary bacterial infection subject to local influences, there is no one remedy that works equally well for most people. It is typical for experienced people to say that any given method is useless, but that another works very well.Itching can be alleviated through use of over-the-counter topical corticosteroids and antihistamines. Hot showers or baths also will help reduce itching. In cases of severe dermatitis or secondary infection associated with chigger bites, a doctor should be consulted.
There are dozens of methods for treating chigger bites:
- Topical anesthetic may work for short term relief of itching symptoms;
- soaking the bite location in water with Epsom Salts can cause the chiggers to become detached from the skin;
- A topical cream containing an antihistamine
- Wiping the affected area with isopropyl alcohol may also remove some of the offending pests.
- Chigarid, a spot treatment, is a popular, widely available soothing product that forms a protective collodion barrier over the wound.
- Chiggerex a widely available soothing cream.
Home Remedies
All remedies are here for academic purposes only. Never use any home remedy or other self treatment without being advised to do so by a physician.Among the most popular and effective treatments all involve a hot shower or bath accompanied with vigorous scrubbing using cloth and (harsh) soap or typically one of various (drying) antiseptics such as bleach or alcohol as soon as possible.
For quick relief of the itching, splashing on Listerine mouth wash is among the most popular. Also popular is ammonia or Windex. Many others claim relief from various common insect bite or sting remedies.
There is an active debate over the efficacy of the popular remedy: sealing the bite with (clear) nail polish, which typically creates intense itching, often with the plastic film forming a quick, expanding "water blister." People who have experienced this claim that within an hour or so, the itching is gone and the wound will quickly heal. The other side typically argues something like: "Nail polish cannot "smother" the chigger because it has not burrowed into your skin, and it was probably scratched off long ago."
That argument depends on the assumption that the polish supposedly killed a (burrowing) chigger, and if it didn't, the method must be a myth. It does not address the possibility that another mechanism, such as sealing the bite from air, or
removing or neutralizing the stylostome and toxic enzymes otherwise known to remain embedded in the skin for over a week, might be at work.
Nymph
Once the larva has engorged itself on skin and has fallen off its host, the larva develops to its nymph stage. Like the larva, the nymphs are also sexually immature, but more closely resemble the adult.This stage consists of three phases; the protonymph, deutonymph, and tritonymph, respectively. The protonymph and tritonymph morphology are unusual in species of Trombiculidae. The protonymph phase combines larval and protonymph characteristics with deutonymph and tritonymph morphology. The protonymph is an inactive transitional stage. The active deutonymph develops an additional pair of legs (for a total of eight). Lastly, it re-enters inactivity during its transitional tritonymph phase before growing to adulthood.
Adult
As a deutonymph and adult, trombiculid mites are independent predators that feed on small arthropods and their eggs, also found to eat plant material. They live in soil, often found when digging in yards and gardens.Trombiculiasis
Trombiculiasis, also called Trombiculidiasis, is the term coined for the rash or infestation caused by trombiculid mites.External links
- "Chiggers!" at Missouri Department of Conservation
- Chiggers at Pestproducts.com
- Iowa State University Department of Entomology Insect Information Note
- NIH Medline Plus
- Ohio State University Extension Fact Sheet, Entomology, Chiggers, HYG-2100-98
- Trombicula autmunalis
- Taxonomic information at UniProt Consortium and NCBI