4 Responses

1. fooles.troupe

   September 22nd, 2009 at 6:03 am

   1

   It is possible to see a dust mite under a magnifying glass, when the subject is well lit and placed on a black background. A typical house dust mite measures 420 µm in length and 250 to 320 µm in width.

   http://en.wikipedia.org/wiki/Dust_mites

   Any readily obtainable one – I looked at them when a kid – if the one you have is not strong enough – use two in series.

2. nicole h

   September 22nd, 2009 at 6:03 am

   2

   House dust mite
   From Wikipedia, the free encyclopedia
   (Redirected from Dust mites)• Ten things you may not know about Wikipedia •Jump to: navigation, search
   House dust mite

   Dermatophagoides pteronyssinus
   Conservation status
   Secure
   Scientific classification
   Kingdom: Animalia

   Phylum: Arthropoda

   Class: Arachnida

   Subclass: Acarina

   Order: Acariformes

   Family: Pyroglyphidae

   Genus: Dermatophagoides

   Species: D. pteronyssinus

   Binomial name
   Dermatophagoides pteronyssinus
   Trouessart, 1897
   The house dust mite (sometimes abbreviated by allergists to HDM), is a cosmopolitan guest in human habitation. Dust mites feed on organic detritus such as flakes of shed human skin and flourish in the stable environment of dwellings. In nature they are killed by micro-predators and by exposure to direct sun rays. Dust mites are considered to be the most common cause of asthma and allergic symptoms worldwide. The enzymes they produce can be smelled most strongly in full vacuum cleaner bags. The European house dust mite (Dermatophagoides pteronyssinus) and the American house dust mite (Dermatophagoides farinae) are two different species.

   Contents [hide]
   1 Size
   2 Life cycle
   3 Habitat and food
   4 Asthma and allergies
   5 References
   6 External links

   [edit] Size
   It is possible to see a dust mite under a magnifying glass, when the subject is well lit and placed on a black background. A typical house dust mite measures 420 µm in length and 250 to 320 µm in width. Both male and female adult house dust mites are globular in shape, creamy white and have a striated cuticle. A member of the phylum Arthropoda, post-larval stages of house dust mites have eight legs; larval stages have six legs. Dust mites can be transported airborne by the minor air currents generated by normal household activities.

   [edit] Life cycle
   The average life cycle for a male dust mite is 20 to 30 days, while a mated female dust mite can live for 10 weeks, laying 60 to 100 eggs in the last 5 weeks of her life. In a 10 week life span, a dust mite will produce approximately 2000 fecal particles and an even larger number of partially digested enzyme-infested dust particles. [1]

   Bleach and strong soaps do not kill dust mites.[1] A simple washing will remove most, in the waste water. Temperatures of over 60 degrees Celsius (140 degrees Fahrenheit) for a period of one hour are usually fatal to dust mites[2]; freezing may also be fatal. Dust mites reproduce quickly enough that their effect on human health can be significant.

   [edit] Habitat and food
   The dust mite survives in all climates, except at high altitudes where reproduction is halted. A necessary condition for growth (digestion and reproduction) is sufficient absolute humidity. Relative humidity is not a good measure since it varies with temperature. When humidity is less than optimal, dust mites function more slowly, eventually become dormant and may die. Dust mites thrive in the environment provided by beds, kitchens and homes in general, where the sun’s rays do not reach them. Mites remain in mattresses, carpets, furniture and bedding, since they can climb lower down through the fabric to avoid sun, vacuum cleaners, and other hazards, and climb higher up to the surface if necessary to get another skin cell to feed on, when humidity is high. Even in dry climates, dust mites survive and reproduce easily in bedding (especially in pillows) because of the humidity generated by the human body during several hours of breathing and perspiring.

   Dust mites consume minute particles of organic matter. Some species of mites prefer to eat skin cells, a large component of household dust; others prefer flour dust. Dust mites have a rudimentary alimentary system (no stomach) and require most digestion to occur outside their body. For this reason they secrete enzymes and deposit the fungus Aspergillus repens on dust particles, to enable the fungus to pre-digest the organic matter with its enzymes. Dust mites eat the same particle several times, only partially digesting it each time. Between feedings dust mites leave particles to decompose further. Ultimately a fully digested particle, which a dust mite will not eat, is deemed by scientists to constitute fecal matter. On average, a person sheds about 1.5 grams of skin cells and flakes every day (approximately 0.3-0.45 kg per year), which is enough to feed roughly a million dust mites under ideal conditions.[verification needed]. Dust mites in bedding derive moisture from human breathing, perspiration, and saliva.

   [edit] Asthma and allergies
   Main article: Asthma
   The house dust mite’s partially digested food, and fecal matter, is one of the most significant sources of allergens, implicated in allergic asthma, rhinitis, conjunctivitis and dermatitis. One of the more important proteins responsible for the allergic reaction is DerP1, a protease digestive enzyme found in mite feces. Dust mites bodies, made of chitin, are also allergens. Immunotherapy or "allergy shots" have been helpful for sufferers of hay fever and asthma. Steam cleaners may be effective at reducing enzyme allergens since the heat of the steam breaks down (decomposes) the compound. Prolonged exposure of skin to the proteins in dust mite fecal matter reduces its barrier function; this weakness can create a point of entry for allergens and irritants, leading to inflammation and itchiness or pruritis.

   [edit] References
   ^ Dust mites. Specialist Allergy Cleaners.
   ^ "Hotter is better for removing allergens in laundry", American Thoracic Society, May 20, 2007.

   [edit] External links
   Dust Mite Control – from Clemson Extension Home & Garden Information Center
   Dust Mites Center
   Retrieved from "http://en.wikipedia.org/wiki/House_dust_mite"
   Categories: All pages needing cleanup | Wikipedia articles needing factual verification since July 2007 | Acari | Building biology

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3. Mother of four

   September 22nd, 2009 at 6:03 am

   3

   Have you ever heard the word "electon" ? Don’t think you can pick it up at wal=mart though.

4. anissia shoemaker

   September 22nd, 2009 at 6:03 am

   4

   you need a microscope. Not a magnifying glass.