arthropods - arachnids - ticks Flashcards
what are the 2 families of ticks
ixodidae (hard ticks)
argasidae (soft ticks)
tick morphology
adults: four pairs of legs
fuses body segments: head + thorax + abdomen
ixodid: identifying characteristics
mouthparts: projects cranially
scutum: present
females vs males:
-scutum is smaller in females
argasid: identifying characterisitics
mouthparts: not visible from dorsal side
scutum: none
leathery, wrinkled
some have spines
general tick life cycle
-eggs
-larve: 6 legs
-nymph: 8 legs
-adults
-ixodid: 1-3 years, argasid: 1 month to years
tick life cycle: one-host tick
egg: laid on ground
hatches
larva: finds host and feeds
molts on host
nymph: feeds on same host
drops to ground OR molts on host
adult: nonparasitic or feeds on same host
non-parasitic on ground OR mates and drops to ground
egg: laid on ground
tick life cycle: three-host tick
egg: laid on ground
hatches
larva: finds host #1 - feeds and drops off
molts
nymph: finds host #2 - feeds and drops off
molts
adult: finds host #3 - feeds, mates, and drops off
female lays eggs
egg: laid on ground
basic tick pathology and clinical disease
-usually few clinical signs
-bite wounds
-annoyance
-blood loss: anemia if many ticks
-vectors: many disease transmitted by ticks
-tick paralysis: toxic substance in saliva of some ticks; neurological signs - weakness, paralysis
disease tramission between ticks
interstadial transmission:
-disease organism acquired from host by larval or nymph tick
-organism carried through molt to nymph or adult tick
transovarian transmission:
-disease organism passed from adult female tick to eggs via ovaries
-only way one-host tick can serve as vector
tick treatment
-tick removal
-gently cleanse patient skin and wash hands
-NOT mineral oil, petroleum jelly
-goal = remove as soon as possible
tick prevention
-avoid tick habitats
-tick checks
-drugs –> ascaricides: act by prevention tick nervous system function
ixodid tick feed behavior
-3 host tick
-each stage feeds in one large meal
-then spends time off host
ixodes host
many
ixodes characteristics
tiny
inornate
no festoons
anal groove
ixodes scapularis patho
-vector or intermediate host:
bacterial disease = Lyme = borrelia burgdorferi, anaplasma, ehrlichia
protozoal disaces = babesia spp.
-tick paralysis
dermacentor species host
many - dogs, cattle, horses, wildlife, people
dermacentor characterisitcs
3-host tick
ornate
festoons
rectangular basis capitulum
dermacentor patho
-tick paralys: main cause
-vector/intermediate host: bacterial diseases - anaplasma, ehrlich, rickettsia ; protozoal disease - babesia spp.
rhipicephalus sanguineus host
dogs, people
rhipicephalus sanguineus other name
brown dog tick
rhipicephalus sanguineus characteristics
3-host tick
inornate
festoons
hexagonal basis capitulum
rhipicephalus sanguineus patho
-vector/intermediate host: bacterial disease - rickettsia rickettsi, ehrlichia Canis ; protozoal diseases - babesisa canis
rhipicephalus annulatus host
cattle
rhipicephalus annulatus characteristics
1-host tick
inornate
no festoons
hexagonal basis capitulum
rhipicephalus annulatus patho
vector: protozoal disease - babesia bigemina
amblyomma host
many - domestic animals, reptiles, people
amblyomma characteristics
ornate - female has a white spot on scutum
festoons
very long mouthparts
amblyomma patho
-tick paralysis
-vector/intermediate host: bacterial disease - anaplasma phagocytophilum, rickettsia rickettsii, franscisella tularensis, some borrelia species
argasid feeding behavior
-much time spent off host (in host bedding, nesting materials, cracks and crevices, housing)
-feed often and for short periods
-most species rarely found on host
-active at night
otobius species host
cattle
also reported in horses, sheep, dogs, people
otobius characteristics
one-host tick
soft tick features
violin shape
cuticle covered in spines
otobius patho
-decreased production: due to annoyance
-otitis externa: larvae and nymphs live in ear canals
-disease vector: suspected vector for bacterial disease Q fever
