dust mites
Created | Updated Jul 31, 2003
Introduction
Present in our homes and work places, dust mites undoubtedly rule our carpets. Dust mites live in 95% of homes in America and are, whether we realize it or not, of an amount that can cause amazingly severe problems. Ridding homes of these tiny arachnids may be a main priority for those families with emphysemics, asthmatics, and people allergic to dust mites. Dust mites may always be present, but if their population is of a smaller number, there will be fewer problems.
History
In 1920, dust wasn’t much of a deal, but in 1921, researchers suggested that house hold dust might be jumpstarting asthma attacks and allergic reactions. The research did not pose a major threat to anyone, they thought, so reasearch was ended with no regrets of after thoughts until 1964. A man by the name of Voohorst and a group of researchers began to wonder if a mite might be the cause of the reactions. The team found various species of mites that were labeled as house mites. The type of mite that is commonly called the “dust mite,” is scientifically known as Dermatophagoides pteronyssinus, or “skin-eating mites.”
Taxonomy
Taxonomy is the classification of organisms by categories and descriptions. The genus tell into which category the being falls under, and the species describes the actual being. The genus is always first in and organism’s scientific name, and capitalixed. The species follows the genus in is in the lower case form. An organism’s scientific name should always be italicized or underlined.
The Dermatophagoides pteronyssinus falls under the family Astigmata and the suborder Acaridia, or free-living mites. The dust mite and its relative Dermatophagoides farinae make up eighty to ninety percent of all mites found in the household environment.
Biology
To survive in the wild, a human’s residency, a dust mite must fight hard under threats from various dangers and conditions that aren’t exactly perfect. Vacuuming is not a large threat to dust mites, but artificial heating and cooling systems can give mites difficulties. A dust mite has no time for child’s play as it rockets through its short life of forty-five to ninety days. The dust mite can and should be considered a survivor.
Life Cycle
Which came first, the dust mite or the egg? A dust mite passes through four different metamorphic stages before reaching its adult form. The phases are an egg, a larva, a protonymph, a tritonymph, and, finally, an adult with either the male or the female gender.
1. the egg- After mating, the egg will develop for five to eight days before hatching.
2. the larva- When the larva emerges from its spherical prison, it will feed for three to ten days before metamorphosing.
3. the protonymph- A protonymph must wait from four to seven days before reaching its next stage.
4. the tritonymph- The tritonymph must feed on skin particles, the dead bodies of its predecessors, and other organic material in its environment and grow for around five to eight days.
5. the adult- The adult dust mite is capable of breeding within twenty-four hours of full development. The female can lay from thirty to one hundred eggs at one time and a single generation lasts about twenty-five days.
NOTE: Because the house is a controlled environment and dust mite reproduction is not limited by seasons, all phases of dust mite development can be found at any point in the year.
Habitat
The places where the most abundant populations of dust mites are found are in the central areas of a house, bedrooms and family rooms. Looking into the reasons that dust mites would flock to these regions are many, for example, a person spends 75-80% of his or her time in a bedroom, and it is this presence that allows a mite to thrive. The constant respiration provides the tiny arachnids with moisture. Aquatic aquariums, humidifiers, and heavily watered plants can cause the present populations to explode as well.
A human being is constanty shedding skin and other delacacies that dust mites eat, providing a food surplus and heat. In fact, dust mites love bedrooms so much that a double bed-mattress can contain two million dust mites, a six year-old pillow can hold up to a tenth of its weight in dust mite bodies and fecal matter. Another reason that dust mites prefer bedrooms and family rooms is because of the amount of upholstery, carpet, wall and window hangings that they can make their feeding, breeding, and living grounds.
Because dust mites are 75-80% water, moisture is key to their existence. Dust mites lose the most water laying eggs and defecating. This species of mite produces more than twenty fecal pellets daily. Dermatophagoides pteronyssinus, the mite most commonly researched, thrive in a climate of about 25-degrees Celsius and about 75% realative humidity (RH.) A trick that dust mites have developed to keep moist is to cluster together, trapping moisture between their bodies. Surprisingly, these cysts, or huddles, are more beneficial to males and can save half of the moisture that a solitary mite would lose. Even when moisture is plentiful or when heating and cooling systems dry out the environment, the tiny arachnids still clump together.
Scientists have discovered a valuable piece of information that may allow humans to win the war against dust mites. Dermatophagoides pteronyssinus communicate using a vast array of pheromones to locate each other. This is called chemical communication, and scientists say that by interfere with these chemical signals that locate a mite’s peers, the mites will be unable to cluster and die of lack of moisture.
Diet and Digestion
A dust mite’s diet is of the basic things in your house that are virtually impossible to get rid of. Human skin shale and pet dander are among the leading foods for dust mites and also the most prevalent in a household. Skin fungi, molds, and carpet beetle, silverfish, clothes moth, and roach bodies and fragments are also leading victuals for dust mties. Most household dust includes pollen, bacteria, and plant material, along with all the other things that mites eat. Dust mites eat what other creatures will not, so there is plenty to go around.
The common dust mite has a short digestive system that lends a touch of simplicity to their complicated world. The mouth, pharynx, and esophagus are the anatomical components that suck water molecules and food out of the air or off a registered target. The food travels to the ventriculus, or chamber-like stomach, and buds the food cells from the sides, grabs the food particles, breaks down the food as it travels along the gut lumen, then absorbs it as it passes through the guttural epithelium, or membrane, into the haemolymph. The digested food then needs to be excreted from the body through the anus and the rectum at which the digested food is dehydrated and packed in a peritrophic membrane. After expulsion from the body, the digestive process is over.
Allergies Associated With Dust Mites
Dust mites themselves are usually not the cause of allergies in people. The protein that they produce in fecal pellets is really the main cause of allergenic reactions. Rhinitis, wheezing, coughing, itchy, runny eyes, and constant congestion of the nose and ears are some of the more common signs of an allergenic reaction. If symptoms improve outside of living quarters or worsen when linens are changed, vacuuming, or dusting occur, there may be a more serious infestation of dust mites in your house.
Removing and Preventing Dust Mite Infestations
Dust mites, like many arachnids, are hard to kill with ordinary pesticides unless directly applied to the creature. Many professionals agree that removing food sources is a more successful and much less dangerous technique to rid your home of these creatures. There are various methods and solutions that are known to either kill the mites or to neutralize the protein in the fecal matter. Some think that instead of using chemicals to temporarily solve the problem, that constant prevention would be better and safer.
Many prevention methods exist that can be quickly and easily accomplished if done correctly. Polyurethane or plastic covers on mattresses, pillows, and draperies are quick, semi-visible solutions that prevent the dust mites from living directly in an area that you sleep on. Removing carpets, stuffed animals, and draperies are more of a dramatic solution. Washing the bed linens in hot water (over 55 degrees Celsius) once a week or putting sheets for a short duration in the freezeer are also temporary fixes for a possibly serious problem.
Borax is a wonderful solution to end the fight afainst dust mites. The makeup for borax is Na2B4O2•10H2O. It was originally imported under the name of tincal and is identical to the mineral kernite or rasorite except for the water content. Unlike most nonmetals, borax is a good electrical conductor and produces off water when heated. Borax is a known insect/arachnid control, and is also used in fertilizers, flame-retardant, sandpaper, and glass. Borax works first by eating through the exoskeleton of an arachnid or insect, allowing precious moisture to escape and dehydrate the organism. Borax is also capable of suffocation.
Tannic acid, an important ingredient in the tanning of leather, is also used to prevent allergenic outbreaks caused by dust mites. C14H14O11 is extracted fro sumac bark or oak galls. Galls are parisitic growths that inflame a tree’s tissues, causing tannic acid to be emitted. A solution of 3% tannic acid neutralizes the protein in dust mite fecal matter that causes most allergic reactions. The tannic avid formula must be repeated every few months to be effective because it only denatures the protein. Denatures means to chemically change the composition by heating or otherwise.
Rosemary, one of the testing variables in this experiment, is advertised as being able to kill fleas. Fleas, like dust mites, are arachnids and are succeptible to rosemary. Rosmarinus officinalis is the scientific name of this Mediterranean bush. The oil in rosemary dries out the moisture that a mite needs, killing it. Rosemary is also used in perfumes, food seasoning, and liniments because of its fragrance.
Changing the conditions in the dwelling where the nfestation exists can also kill the mites. Dropping the relative humididty below fifty percent, and raising the temperature above room temperature can also make the dust mite’s envireonment miserable and hard to live in. Creating an intolerable atmosphere to the dist mites will kill them or make your life a little sweeter knowing that you are torturing the creatures that have tortured you.
There are several commercial products that can also kill dust mites. Acarasom, Allergen by Bissel, and Dustmitex are all Food and Drug Administration (FDA) approved to kill dust mites and neutralize allergens. Acarasom is a product that is applied through a spray nozzle and does not seem to be harmful to humans, house pets, or the environment. Dustmitex is a borate compound that is known to eliminate insects and arachnids. To apply Dustmitex, you mix the substance with water and spray on surfaces that need the absence of dust mites. This product is clear, has no smell, and will not stain light fabrics with its neutral pH and low toxicity. The last product, Allergen, is available in many forms. You can sprinkle it on carpet and furniture and vacuum it up or spray it on draperies, etc. Allergen is said to have low toxicity and be hypoallergenic.
As well as useful things to do to get rid of dust mites, there are also many activities that are useless. Stay-at-home spouses may often dust to get rid of the traveling settlement of Dermatophagoides pteronyssinus that may cause the partner to get the sniffles. In truth, this can lend itself to more frequent and more reactive results, because when the dust is stirred up, a person is more likely to inhale the disturbed dust compare to a stationary coating of the surface of a counter-top or bookcase. Using a damp cloth or rag, specially designed cloths to trap dust, or not dusting at all may eliminate these problems.
Another behavior that is mostly useless is vacuuming. When a person vacuums, he or she is only pulling five to ten percent of the dust mites in that area out of the carpet. The percentage of mites that were vacuumed out of the carpet are extremely small and can go through the fibers of a vacuum bag. A HEPA (high efficiency particle arrestor) can eliminate the problem of redistribution and provide a wonderful habitat for mites.
Viewing Dust Mites
In length and appearence, dust mites are rather unremarkable. They measure about 1/25 of a millimeter to 1/100 of a millimeter and have a grayish, black, or reddish coloration. A single mite is oval in shape and has eight legs like all arachnids. The mouth and antennae parts are clumped together at the front of the body forming a sort of “head.” Most of the time, dust mites will have tiny beads of moisture and specks of food on its exoskeleton and feet. To preserve moisture, dust mites are usually accompanied by other mites; in other words, where there is one dust mite, there are many. A microscope with at least ten-magnification power is needed to view dust mites; a dissecting microscope is suggested. Sometimes, you can even see them with a strong camera lens or magnifying glass.
Importance of Research
Dust mites are largely underestimated as a potential allergen in the house environment. In the past twenty years, research has increased on the possibility of dust mites being a serious and possibly deadly catalyst in an allergic reaction. Pollen and mold were the two most commonly assumed allergens by doctors and families everywhere until contradictory evidence was provided. The education of Dermatophagoides pteronyssinus and Dermatophagoides farinae has risen dramatically and will most likely continue to rise due to the increase in breathing and allergy problems.
