Have you ever been lying in your bed, and suddenly, your nose itches and you constantly sneeze, or wake up with the need to scratch some part of your body?… You might be exposed to “mites”, microscopic arachnids that live around us.
Mattresses, carpets, pillows, stuffed animals, your body!… and any dark and warm place that contains dust, is the ideal space for the development of these small organisms, and some of their species are responsible for allergies and other diseases.
Dust mite or common mite, cheese mite, red velvet mite, and scabies mite are some of their representative species.
Do you want to learn a bit more about this extraordinary group of animals? Take a look at their main characteristics, where they are found, what they feed on, what diseases they produce, and how to effectively eliminate them!
What are mites and where can they be found?
“Mites” are small organisms (sometimes microscopic) belonging to the largest and most varied animal phylum, “Arthropoda”, to the class “Arachnida”, and to the subclass “Acari, which means “tiny, that does not cut”, hence their name”
In any habitat you can imagine, there are mites!
They are distributed all over the world, with terrestrial and aquatic species adapted to all the planet’s environments, as well as urban and domestic places, grouped in colonies and living freely or as a parasite (on a host organism).
Caves, marshes, the sea, polar regions, hot springs, deserts, the soil, leaves, a cat’s ears, the trachea of bees, human skin… are some of the unusual places where mites can be found.
Particularly, the skin of all humans produces enough scales or skin debris to breed thousands of mites for several generations!
Mattresses, carpets, fabrics, blankets, sofas, the face, eyelashes, eyebrows, beards… represent an excellent microhabitat for mites, as they provide the conditions required for their development: warmth, humidity, and food (human skin scales).
Did you know…? There is a species of parakeet that harbors 25 species of mites in its feathers!
Mite Characteristics
Externally
- Oval, elongated, cylindrical body; symmetrical, divided into two regions: anterior (or gnathosoma) and posterior (idiosoma), covered by an exoskeleton (external skeleton) that protects it and by bristles (hairs) that act as tactile organs.
- The anterior region is made up of the oral opening, two pincer-like mouthparts (chelicerae), and two sensory structures (pedipalps), used to locate and manipulate food.
- The posterior region contains most of its organs, two openings (one genital and one anal), a type of shield (dorsum) in the form of plates, and four pairs of articulated legs, meaning divided into pieces that move (called segments).
- Certain species (Eriophyids) have only two pairs of legs.
- Lack wings and antennae.
- Most mite species are blind, only some have one or two pairs of simple eyes (ocelli), tiny spots sensitive to light changes.
- Variable size (from 0.1 to 10 millimeters).
- They present different colors, depending on the species and their diet (transparent, whitish, green, light brown, red, yellow…)
Did you know…? The estimated lifespan of a mite is very short, varying between 15 and 90 days.
Internally
- Simple digestive system, divided into three areas: stomodeum (initial part), mesodeum (middle part) containing the intestine, and proctodeum (final part) ending with the anus, where it expels its waste.
- They breathe through tracheae (fine tubes), which can connect with small holes in the skin (stigmata).
- The nervous system consists of a small mass and two nerve cords, controlling the body’s sensory organs.
- They have a heart, acting with an open circulatory system, transporting hemolymph (blood) throughout the body.
- They possess reproductive organs in the abdomen area; distinguishing female (ovaries) and male (penis).
How do mites reproduce?
Reproduction is sexual, and fertilization is internal; the transfer of male sexual cells to the female occurs in three ways (depending on the species):
Through the penis (male member); using the pincers as a copulatory organ; or via a spermatophore (tiny bag containing sperm), which can be transmitted from belly to belly, or deposited on the ground to be picked up by the female.
Most mites are oviparous (lay eggs), some can be ovoviviparous (lay eggs that have a formed embryo and are about to hatch) or viviparous (can have fully formed organisms).
Three or four days after fertilization, the female lays eggs (30 to 50 in a single laying); development occurs in four stages: egg, larva, nymph, and finally adult, experiencing a series of molts to grow.
Did you know…? The mites that inhabit the human face (Demodex folliculorum) are so small that a dozen of them could fit on the head of a pin, and by the way, they mate at night, while you sleep!
How are mites classified?
It’s not certain how many mite species exist in the world, although about 50,000 species are known, it’s estimated there are thousands more to be discovered.
Their classification is complicated and still under study; the most accepted classifies mite species into three superorders: Acariformes, Parasitiformes, and Opilioacariformes.
Acariformes
The most numerous, with over 30,000 species distributed in 350 families, characterized because the hairs covering their body (setae) are lined with a substance that reacts to microscope light (actinoquinone).
Representative Species
Harvest mite (Trombicula autumnalis), flour mite (Acarus siro), dust mite (Dermatophagoides farinae)…
Opilioacariformes
The oldest mites, of strange appearance, distinguished by the length of their legs compared to the body and by maintaining structures from their ancestors (such as six pairs of eyes). It includes about twenty species.
Representative Species
Opilioacarus segmentatus, Opilioacarus texanus, Eucarus italicus…
Parasitiformes
Parasitic mites, meaning they inhabit living beings (especially birds and mammals, including humans) and cause various diseases. The famous ticks are included in an order called “Ixodida.”
Representative Species
Red spider mite (Tetranychus urticae), Eriophyes cerasicrumena, Varroa mite (Varroa destructor)…
Did you know…? “Gamasellus” is a blind parasitic mite that uses the sensory hairs on its legs to locate prey, and once captured with the chelicerae (pincers), injects a deadly cocktail into its victim.
What do mites eat?
The diet of mites varies by species, behaving as:
- Phytophagous: They feed on plants, vegetables, flower nectar, leaf fragments, fruits.
- Parasitic: They feed on the skin or blood of their host (animal or human).
- Predatory: Their diet includes microorganisms, small arthropods, or other smaller arachnids (even mites).
- Detritivores: They consume organic residues left by plants and other animals (scales, skin pieces, hair, etc.).
- Mycophagous: They feed on fungi.
- Saprophagous: They subsist on dead plant matter, wood, bacteria…
- Coprophagous: They feed on the feces of other animals.
Certain mite species enjoy sweet foods (desserts, jams, candies, powdered milk…) as well as grains and storage products (wine, flour, ham…).
Did you know…? Some of our foods are the territory of mites, like Mimolette cheese, which owes its flavor to the activities (and waste) of the “cheese mite (Tyrophagus putrescentiae)”
Diseases caused by mites
About 25 known species of mites are responsible for causing allergic diseases in animals and humans, and the main cause is their feces!
Yes, their fecal matter contains a protein that causes mite allergy, causing respiratory problems (asthma and rhinitis) in humans.
Particularly, “house mites” are significant producers of potent allergens (substances that can cause an allergic reaction) in house dust, which also contains fibers, fungal spores, bacteria, human skin remnants…
Certain species are responsible for creating skin diseases (scabies, dermatitis); even dead mites can continue causing allergies!
Asthma and Rhinitis
Caused by the dust mite. Asthma manifests with cough, chest tightness, wheezing (whistling sound when breathing), and difficulty performing physical exercise and laughing; symptoms persist throughout the year.
Rhinitis causes episodes of repetitive sneezing, tearing, and generally, intense nasal congestion, especially each morning upon waking up, and at night when going to bed.
Scabies
A disease caused by the female “scabies mite” by digging tunnels in the outer layers of the skin of animals (dogs and cats), to feed and lay her eggs, causing itching, irritation, redness, and sores or ulcers on the skin.
It can be transmitted from one organism to another through skin contact, even to humans.
Other diseases
“Demodex folliculorum and Demodex brevis mites” cause inflammation of the skin, with the presence of small red pimples on the face, back, and upper chest, as well as a crust at the base of the eyelashes in humans (and any mammal).
Particularly “the bird mite” can cause anemia, feeding on the blood of its host (mainly poultry, such as chickens).
“The Varroa mite” is the cause of Varroasis disease, a serious affliction in bees caused when it feeds on the hemolymph (blood) of adult bees and the brood.
How to eliminate mites?
Watering regularly, using insecticides, and using organic covers made of harvest residues will keep the presence of mites in crops under control.
To eliminate mites from the mattress or bed, one of the effective methods is to increase the ventilation of the house, and reduce as much as possible, elements that may accumulate dust (carpets, stuffed animals…) or well, vacuum them constantly.
You can also air out the mattress, change the sheets continuously, use anti-mite covers, clean the house areas, and use low-toxicity chemical products (acaricides).
In the case of patients allergic to mites, it is advisable to avoid contact with hairy or feathered pets in their homes.
Did you know…? A study conducted by the British University of Kingston showed that leaving the bed unmade helps kill mites!
Is there any treatment against mites?
Certain anti-allergic medications can be effective for treating allergies caused by mites, as well as antibiotics, creams, and lotions for skin conditions, containing chemicals that destroy mites and their eggs.
It is always advisable to seek medical consultation for an accurate diagnosis by a specialist, with the corresponding treatment.