Ticks

Question 1

• What are the direct and indirect effects of ticks?

Answer 1

Direct – anaemia, inflammation at site of attachment, paralysis
Indirect – ticks as vectors

Question 2

• What are the two main parts of a tick’s mouthparts and what are their functions?

Answer 2

Chelicerae cut a hole in the skin

Hypostome enters hole and is held in by the backwards facing teeth

Question 3

• What are the two main types of ticks?

Answer 3

Ixodidae – hard ticks & Argasidae – soft ticks

Question 4

• What is the main difference between hard & soft ticks?

Answer 4

Soft ticks mouth parts are not visible

Question 5

• What are the two types of tick lifecycles?

Answer 5

Nidicolous & non-nidicolous

Question 6

• What pathogen is the soft tick, Argas persicus (the fowl tick) responsible for transmitting

Answer 6

Borrelia anserine

Question 7

• Describe the lifecycle of a soft tick

Answer 7

Larvae attack vertebrate hosts inhabiting the nest, burrow
Soft ticks feed rapidly over several minutes to a few hours depending on stage and species. They also feed several times during each life stage
Soft tick species may also undergo between 2-7 nymphal moults before reaching the adult stage
Adult females can feed and lay eggs several times during their lifetime

Question 8

• What is questing?

Answer 8

Hard ticks find hosts by questing, questing ticks crawl up the stem of grass or perch on the edges of leaves on the ground in a typical posture with the front legs extended, ready to climb onto a passing host

Question 9

• Describe the lifecycle of a hard tick

Answer 9

Single hexapod larval stage
Hard ticks feed once during each life stage
Single octopod nymphal  stage
Reproductive adult stage
Female lay eggs and then die

Question 10

• What is the most common tick in the UK?

Answer 10

Ixodes ricinus

Question 11

• Describe the appearance of Ixodes ticks

Answer 11

Long mouthparts but no eyes, inornate and have no festoons, the anal groove is distinct and surrounds the anus anteriorly

Question 12

• How can you use the anal groove to determine if a tick is a member of the genus Ixodes?

Answer 12

Anal groove in front of the anus – genus Ixodes, no groove in front of anus – non Ixodes

Question 13

• What is borreliosis?

Answer 13

Lyme disease, most common tick-borne disease in the UK, caused by the bacteria Borrelia burgdorferi

Question 14

• What is louping ill?

Answer 14

Infectious ovine encephalomyelitis – virus which attacks the CNS, causes significant suffering in clinically affect animals

Question 15

• What are Babesiosis & Theileriosis similar to?

Answer 15

The protozoans that cause malaria and sleeping sickness, they parasite the red blood cells of vertebrates

Question 16

• What pathogen is responsible for the spread of Babesia bovis?

Answer 16

Rhipicephalus sp.

Question 17

• Which tick is responsible for the spread of this pathogen in Northern Europe?

Answer 17

Ixodes ricinus

Question 18

• What does Babesia bovis cause?

Answer 18

Pyrexia, severe haemolytic anaemia, haemoglobinuria and death of infected animals

Question 19

• What is the difference between trastadial & transovial?

Answer 19

Transtadial – keep a pathogen through the different stages of development
Transovial – passes pathogen on to eggs