Ectoparasites II- Ticks Flashcards
Why are ticks so important?
Obligate blood-sucking parasites
Can cause disease directly and indirectly
Describe insects
Body parts: head, thorax, abdomen
Legs: 3 pairs (6)
Antennae: present
Wings: present or absent
Describe arachnids
Body parts: cephalothorax, abdomen, or completely fused (ticks are the latter)
Legs: 4 pairs (8)
Antennae: absent
Wings: absent
What do ticks not have morphologically?
Antennae
Mandibles
Wings
What do ticks have morphologically?
Capitulum
Idiosoma (body)
Legs
What are ticks like in family Argasidae?
Soft (“argasid”) ticks
What are ticks like in family Ixodidae?
Hard (“ixodid”) ticks
Describe the morphology of Argasid/soft ticks
Cannot see mouthpart
No scutum
Leathery integument
Not sexually dimorphic
Describe the life cycle of Argasid/soft ticks
Each life stage may use multiple hosts for multiple, quick feedings (larva, nymph, adult)
Females lay multiple small egg batches
Describe the morphology of Ixodid/hard ticks
Can see the mouthparts
Female has a partial scutum, male has a complete scutum
They are sexually dimorphic
Describe the life cycle of Ixodid/hard ticks
1, 2, 3- host life cycle
Each life stage feeds on one host for a single feeding, usually taking a week (larva, nymph, adult)
Females lay single large egg batch and then die
What is the general life cycle of ticks?
Eggs
Six-legged larva
Eight-legged nymph
Eight-legged adult
How many nymphal stages do sift ticks have?
2 or more
How many nymphal stages to hard ticks have?
1
Describe the hard tick life cycle for 1-host
Egg hatches to larva
Larva feeds on host 1—molts to nymph— nymph feeds on host 1— molts to adult— adult feeds/mates on host 1— drops off
Female lays eggs, dies off host
Describe hard tick life cycle for 2-host
Egg hatches Larva feeds on host 1--- molts to nymph--- nymph feeds on host 1--- drops off Molts to adult off host Adult feeds/mates on host 2--- drops off Female lays eggs, dies off host
Describe hard tick life cycle for 3-host
Egg hatches Larva feeds on host 1--- drops off Molts to nymph off host Nymph feeds on host 2 --- drops off Molts to adult off host Adult feeds/mates on host 3--- drops off Female lays eggs, dies off host
Where do we find soft ticks?
Habitat preference: nidicolous
Environment: tolerate arid environments
Where do we find hart ticks?
Habitat preference: non-nidicolous
Environment: prefer humid environments
What is the host of argas spp?
Mainly birds and bats
Describe Argas spp.
Leathery cuticle
Flat body margin: suture line
Argas persicus: “fowl tick”, “blue bug”, eastern US
What is the host of Ornithodoros spp?
Mainly mammals
Describe Ornithodoros spp.
Leathery cuticle
Rounder body margin
No suture line
What is the host of Otobius megnini?
1-host soft tick: cattle, horses
Describe the stages of Obtius megnini
Larva, 2 nymphal stages feed in same ear
Adult stages do not feed
What does Otobius cause?
Nymphal tegument spiny: “spinose ear tick”
What is the passive method of ticks finding a host?
Ambush/questing
Ticks sit and wait for host, then wave forelegs frantically when sense cues
Requires direct contact
What is the active method of ticks finding a host?
Hunting
Leave resting environment to attack hosts when sense cues
What is the host of Ixodes scapularis?
3-host tic
Immature ticks: rodents, birds, lizards
Adult ticks: white-tailed deer, livestock
When are the adult stages of Ixodes scapulairs active?
Cool weather
Where is Ixodes pacificus located?
Western US
What is the 2 year life cycle of Ixodes scapularis important for?
Maintenance of Lyme disease agent
What is the key morphologic difference between Ixodes and other hard ticks?
Location of anal groove
What is the host of Amblyomma americanum?
3-host tick
All stages: wide host range, but prefer white tailed deer
What does Amblyomma americanum have a high tolerance for?
Warm, humid climates
What is the host of Amblyomma maculatum?
3-host tick
Immature ticks: birds, small mammals
Adult ticks: primarily cattle (“gotch ear”)
What does Amblyomma maculatum have a high tolerance for?
Hot environments
What is the host of Dermacentor variabilis (american dog tick)?
3-host tick
Immature ticks: prefer rodents
Adult ticks: prefer canine hosts
What is the host of Dermacentor andersoni?
3-host tick
Immature ticks: prefer rodents
Adult ticks: deer, sheep, cattle, etc.
What is the host of Rhipicephalus sanguineus (brown dog tick)?
3- host tick
All stages: narrow host range, found wherever dogs are
Does Rhipicephalus sanguineus tolerate cold weather?
No
Describe Rhipicephalus (Boophilus) annulatus
1-host ticks: prefer cattle
Cattle tick, cattle fever tick
Describe Rhipicephalis (boophilus) microplus
1-host ticks: wider host range
Southern cattle fever tick
