Ectoparasites II- Ticks

Question 1

Why are ticks so important?

Answer 1

Obligate blood-sucking parasites

Can cause disease directly and indirectly

Question 2

Describe insects

Answer 2

Body parts: head, thorax, abdomen
Legs: 3 pairs (6)
Antennae: present
Wings: present or absent

Question 3

Describe arachnids

Answer 3

Body parts: cephalothorax, abdomen, or completely fused (ticks are the latter)
Legs: 4 pairs (8)
Antennae: absent
Wings: absent

Question 4

What do ticks not have morphologically?

Answer 4

Antennae
Mandibles
Wings

Question 5

What do ticks have morphologically?

Answer 5

Capitulum
Idiosoma (body)
Legs

Question 6

What are ticks like in family Argasidae?

Answer 6

Soft (“argasid”) ticks

Question 7

What are ticks like in family Ixodidae?

Answer 7

Hard (“ixodid”) ticks

Question 8

Describe the morphology of Argasid/soft ticks

Answer 8

Cannot see mouthpart
No scutum
Leathery integument
Not sexually dimorphic

Question 9

Describe the life cycle of Argasid/soft ticks

Answer 9

Each life stage may use multiple hosts for multiple, quick feedings (larva, nymph, adult)
Females lay multiple small egg batches

Question 10

Describe the morphology of Ixodid/hard ticks

Answer 10

Can see the mouthparts
Female has a partial scutum, male has a complete scutum
They are sexually dimorphic

Question 11

Describe the life cycle of Ixodid/hard ticks

Answer 11

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

Question 12

What is the general life cycle of ticks?

Answer 12

Eggs
Six-legged larva
Eight-legged nymph
Eight-legged adult

Question 13

How many nymphal stages do sift ticks have?

Answer 13

2 or more

Question 14

How many nymphal stages to hard ticks have?

Answer 14

1

Question 15

Describe the hard tick life cycle for 1-host

Answer 15

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

Question 16

Describe hard tick life cycle for 2-host

Answer 16

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

Question 17

Describe hard tick life cycle for 3-host

Answer 17

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

Question 18

Where do we find soft ticks?

Answer 18

Habitat preference: nidicolous

Environment: tolerate arid environments

Question 19

Where do we find hart ticks?

Answer 19

Habitat preference: non-nidicolous

Environment: prefer humid environments

Question 20

What is the host of argas spp?

Answer 20

Mainly birds and bats

Question 21

Describe Argas spp.

Answer 21

Leathery cuticle
Flat body margin: suture line
Argas persicus: “fowl tick”, “blue bug”, eastern US

Question 22

What is the host of Ornithodoros spp?

Answer 22

Mainly mammals

Question 23

Describe Ornithodoros spp.

Answer 23

Leathery cuticle
Rounder body margin
No suture line

Question 24

What is the host of Otobius megnini?

Answer 24

1-host soft tick: cattle, horses

Question 25

Describe the stages of Obtius megnini

Answer 25

Larva, 2 nymphal stages feed in same ear

Adult stages do not feed

Question 26

What does Otobius cause?

Answer 26

Nymphal tegument spiny: “spinose ear tick”

Question 27

What is the passive method of ticks finding a host?

Answer 27

Ambush/questing
Ticks sit and wait for host, then wave forelegs frantically when sense cues
Requires direct contact

Question 28

What is the active method of ticks finding a host?

Answer 28

Hunting

Leave resting environment to attack hosts when sense cues

Question 29

What is the host of Ixodes scapularis?

Answer 29

3-host tic
Immature ticks: rodents, birds, lizards
Adult ticks: white-tailed deer, livestock

Question 30

When are the adult stages of Ixodes scapulairs active?

Answer 30

Cool weather

Question 31

Where is Ixodes pacificus located?

Answer 31

Western US

Question 32

What is the 2 year life cycle of Ixodes scapularis important for?

Answer 32

Maintenance of Lyme disease agent

Question 33

What is the key morphologic difference between Ixodes and other hard ticks?

Answer 33

Location of anal groove

Question 34

What is the host of Amblyomma americanum?

Answer 34

3-host tick

All stages: wide host range, but prefer white tailed deer

Question 35

What does Amblyomma americanum have a high tolerance for?

Answer 35

Warm, humid climates

Question 36

What is the host of Amblyomma maculatum?

Answer 36

3-host tick
Immature ticks: birds, small mammals
Adult ticks: primarily cattle (“gotch ear”)

Question 37

What does Amblyomma maculatum have a high tolerance for?

Answer 37

Hot environments

Question 38

What is the host of Dermacentor variabilis (american dog tick)?

Answer 38

3-host tick
Immature ticks: prefer rodents
Adult ticks: prefer canine hosts

Question 39

What is the host of Dermacentor andersoni?

Answer 39

3-host tick
Immature ticks: prefer rodents
Adult ticks: deer, sheep, cattle, etc.

Question 40

What is the host of Rhipicephalus sanguineus (brown dog tick)?

Answer 40

3- host tick

All stages: narrow host range, found wherever dogs are

Question 41

Does Rhipicephalus sanguineus tolerate cold weather?

Answer 41

No

Question 42

Describe Rhipicephalus (Boophilus) annulatus

Answer 42

1-host ticks: prefer cattle

Cattle tick, cattle fever tick

Question 43

Describe Rhipicephalis (boophilus) microplus

Answer 43

1-host ticks: wider host range

Southern cattle fever tick