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Flashcards in Module 12 Mites Deck (10):

mites taxonomy

Subphylum chelicerate
Class Arachnida
Order Acari


order acari characteristics

largest chelicerate group
various habitats: terrestrial, aquatic, parasitic


anatomy of mites

magma: gnathosoma (mouthparts), pedipalps, chelicerate
idiosoma: fusion of thorax/abdomen


development of mites

egg - larva - nymph - adult
nymph/adult have 4 pairs of legs
larvae only 3 pairs


medical importance of mites

1. temporary irritation of skin due to bite
2. persistent dermatitis by skin invasion
3. mite-induces allergies
4. transmission of pathogens
5. intermediate host for tapeworms
6. invasion of canals and passages
7. acrophobia (feat of mites)
8. delusory acariosis: psychological condition of attack by mites


disease conditions with mites

Acarinism: infestation with mites
Ascariasis: any disease caused by mites


mite-induced Dermatitis

Demodicidae and Sarcoptidae are important families
is a skin reaction from feeding or burrowing of mites


Family Trombiculidae

-larval stage of red velvet mites
-yellow, orange, or red
-found in large numbers
50 spp affect humans (Trombicula alfreddugesi*)


development of chiggers

eggs on ground - larva
larvae picked up by host on whom they feed
continue development as free-living predators



infestation by chiggers
-ectoparasites: don't burrow into skin, just pierce skin with chelicerae and then skin swells around it
-don't feed on blood but on skin cells
-stylostome is used as a feeding tube
-symptoms: bite site irritation, itching
-treatment: application of medicine within first few hours to alleviate itching/infection