Acarology

classification and morphology

• acari
  • tick > 1mm
    • hard ticks Ixodidae
    • soft ticks Argasidae
    • Nuttalliellidae
  • mite < 1mm
    • scrub typhus mite, Chigger mite Trombiculidae
    • scabies mite Sarcoptidae
    • house dust mite Pyroglyphidae

• only 1 body part
  • front end part is not head, but mouth
• adult 8 legs, larvae 6 legs
• breathe through body surface
  • stigmata (respiratory hole)
    • prostigmata
    • astigmata
    • mesostigmata
    • metastigmata
  • whole surface by diffusion
    • tick living in 400m depth of seawater

tick

• eyes are on frontal edge near the roots of the first pair of legs
• scutum (hard shell)
  • covers whole back of male
  • covers only frontal part of female by which female can pool mammal blood
• parity
  • hard tick is semelparity (single oviposition)
  • soft tick is iteroparity (multiple ovopositions)
• tick live years, mostly 2-3 years, at longest 7 years

• transstadial transmission of rickettsia, bacteria or virus

environmental tick control

• alternate environment to destroy ticks' habitat
  • clean up ground cover

chigger mite

• 0.15 - 0.3 mm
• transovarial transmission of Orientia tsutsugamushi
• "co-feeding" multiple chigger mites aggregate on skin of mammals