Ticks Flashcards
Ticks are ________ parasites
Obligate blood-sucking parasites
T/F: cat’s can’t get ticks because they are good groomers
False
- can still get ticks and tick borne diseases
Body parts of ticks
- cephalothorax
- abdomen
OR, completely fused
How many legs do ticks have?
4 pairs = 8 total
Do ticks have antennae?
No
Do ticks have wings?
No
What body parts do ticks not have?
- antennae
- mandibles
- wings
What do ticks do have?
- capitulum (mouth parts)
- idiosoma (body)
- legs
Capitulum
Composed of: hypostome, palps, and chelicerae
What parts of a tick actually enter the host?
Hypostome and chelicerae
What does tick saliva contain?
Anticoagulatory factors and anti inflammatory factors to allow for a smooth, clean blood meal
What are the 2 main families in the class Arachnida?
Argasidae
- soft (argasid) ticks
Ixodidae
- hard (ixodid) ticks
Argasid morphology
- cannot see mouthparts sticking out from a dorsal view
- no scutum due to small blood meals
- leathery integument
- males and females look the same
Argasid life cycle
Each stage may use multiple hosts for multiple, quick feedings
- larva, nymph (multiple instars), adult
- females lay multiple small egg batches after each feeding
Ixodid tick morphology
- mouthparts seen dorsally and ventrally (seen in larval, nymphal, and adult stages)
- female has partial scutum, male has full scutum
- sexually dimorphic
Ixodid life cycle
Each life stage feeds on one host for a single feeding, usually taking about a week
- 1, 2, 3 host life cycles
- larva, nymph, adult
- females lay single large egg batch
_____ and _____ stages of Ixodid have a partial scutum
Nymphal and larval
All adult ______ ixodid ticks require a warm blood meal
Female
- males do not require blood meal in adult stage
- make egg batch after feeding (20,000 eggs) –> most offspring survive
- will die after making one batch
Number of nymphal stages
- > 2 for soft ticks
- 1 for hard ticks
Habitat preference of soft ticks
Nidicolous
- tolerate arid environments
Habitat preference of hard ticks
Non-nidicolous
- prefer humid environments
Argasidae genera
- argas
- ornithodoros
- otobius
Ixodidae genera
- ixodes
- amblyomma
- dermacentor
- rhicephalus
Argasidae - Argas spp
Hosts include birds and bats
- leathery cuticle, flat body margin (suture line)
- Argas persicus: fowl tick (blue bug) of eastern US
Argasidae - Ornithodoros spp.
Hosts include mammals
- leathery cuticle
- rounder margin
- no suture line
Argasidae - Otobius megnini
1 host soft tick (cattle, horses)
- larva, 2 nymphal stages feed in same ear
- adult stages do not feed!
- nymphal tegument spiny (spinose ear tick)
Which stages of Otobius megnini are parasitic?
Larval and nymphal
Passive method of host finding
Ambush/questing
- ticks sit and wait for host, then wave forelegs frantically when sense cues
- requires direct contact!
Active method of host finding
Hunting
- leave resting environment to attach (run/walk to) hosts when sense cues
What tick is both a hunter and a quester?
Lone star tick (Amblyomma americanum)
Ixodes scapularis
3-host tick
- immature: rodents, birds, lizards
- adults: white tailed deer, livestock
- adult stages active in cool weather
What tick appears similar to I. scapularis?
Ixodes pacificus
- occurs in western US
Black legged tick
Ixodes scapularis
- 2 year life cycle that is important for maintenance of Lyme disease
- life cycle in southern US may be complete in 1 year
Location of ______ is key morphological difference between Ixodes vs other hard tick genera
Anal groove
- anal groove of Ixodes encircles anus anteriorly
Amblyomma americanum
3 host tick
- all stages: wide host range (prefer white tailed deer)
- high tolerance for warm, humid climates
- very aggressive
- most common tick in southern US
Amblyomma maculatum
Gulf coast tick
- markings on scutum similar to Dermacentor variabilis
- A. maculatum has longer moutparts
Dermacentor variabilis
American dog tick - 3 host tick
- immature: prefer rodents
- adult: prefer canine hosts
Dermacentor andersoni
Rocky Mountain wood tick - 3 host tick
- immature tick: prefer rodents
- adult tick: deer, sheep, cattle, etc
Are D. variabilis and D. andersoni found in the same region?
No
Rhipicephalus sanguineus
Brown dog tick - 3 host tick
- all stages: narrow host range (found wherever dogs are)
- does not tolerate cold
- infests kennels, houses, etc
R. (Boophilus) annulatus
1 host ticks
- prefer cattle
- cattle tick, cattle fever tick
R. (Boophilus) microplus
1 host ticks
- wider host range
- southern cattle fever tick
______ and _____ eradicated from US
R. annulatus and R. microplus
- reportable!
Goals of tick prevention
- kill existing ticks on animal
- repel new ticks/prevent bites
- provide residual activity
- reduce/eliminate stages in environment
