Arthropod Ectoparasites

Question 1

Mites and ticks have how many legs?

Answer 1

8 legs

Question 2

Mites classification

Answer 2

Phylum: Arthropoda
Class: Arachnida
Order:
- Mesostigmata (oval)
- Promastigata (long)
- Amastigata (round)

Question 3

Features of mites

Answer 3

• 8 legs but 6 legs in nymphs
• Stomata (breathing tube)
• Coxae (joints)
• Pedicles (pads)
• Setae (hairs)
• Lobes
• Chelicerae (mouth)

Question 4

Mites causes:

Answer 4

• mange
• itchiness (pruritis)
• depilation and crusty lesions)

Question 5

Life cycle of mites is

Answer 5

entirely on host so spread is by contact but some via fomates (like lice)

Question 6

Where are Cheyletiealla mites found? (oval)

Answer 6

On surface

Question 7

Where are Demodex (long) mites found?

Answer 7

In hair follicle

Question 8

Where are Sarcoptes (round) mites found?

Answer 8

In tunnel of skin/hair

Question 9

Amastigata- sarcoptid mites (round) are

Answer 9

burrowing mites which cause scabies in animals

Question 10

Microscopic mites are diagnoses using

Answer 10

skin scrapings to recover mites

Question 11

Treatment of mites

Answer 11

1. Ivermectin-based monthly treatments
2. Insecticidal washes
3. monitoring animals during treatment by skin scrapings to ensure treatment works and no overdose
4. treat fomites and in-contact animals

Question 12

Ticks are considered

Answer 12

“most correct form of parasite”

Question 13

Ticks classification

Answer 13

Phylum: arthropoda
Class: arachnida
Order: Acarina

Question 14

Lifecyle of ticks

Answer 14

Eggs–> larvae–> nymphs–>adult

1 host: all stages on one host )Rhipicephalis australia microplus)
2 host
3 host (Ixodes)

Question 15

Features of Ticks

Answer 15

• 8 legs in adults and nymphs (6 in larvae)
• scrotum
• capitulum
• leathery folded exoskeleton allows for expansion during blood ingestion
• hard or soft
• mouthparts downwards or upwards

Question 16

Pathogenesis of Tick

Answer 16

• Anaemia
• Tick worry
• Toxicosis from salivary toxins
• inhibits immune processes and clotting
• transmits pathogens e.g. Theileria, babesia, Lyme disease

Question 17

Tick paralysis is caused by

Answer 17

Ixodes holocyclus

Question 18

Cattle tick infection is caused by 2:

Answer 18

1. Rhicephalis australia

2. Haemaphysalis longicornus (bush tick)

Question 19

Diagnosis of Ticks

Answer 19

• visible so you can see them
• worry: animals rubbing
• vectors for protozoa
• identify tick- collect into >70% alcohol
• For PCR, collect in 100% alc

Question 20

Treatment and control of ticks

Answer 20

• quarantine of property and treatment/de-stock
• pasture spelling
• tick resistant cattle; Bos Indicus
• Acaricides
• vaccines (Tick Guard) is aimed at gut antigens with ingested antibody causing leaky gut

Question 21

Elements of IPM control

Answer 21

1. Restrict ectoparasites numbers overall
2. Reduce ectoparasite numbers in environment
3. Reduce ectoparasites developing on animals

Question 22

1. Restrict ectoparasites numbers overall by:

Answer 22

• physical barriers using repellents, screens, nets & Bob’s trap
• sterile fly release (for Screw worm fly), fruit fly
• Insect Growth Regulator (IGR) hormone to prevent development

Question 23

2. Reduce ectoparasite numbers in environment by

Answer 23

• IGRs, insecticide sprays, flea bombs
• Pasture spelling to allow death from heat/drying esp ticks
• Alternative cropping- keep hosts away
• remove carrion
• dung beetles to reduce breeding material (dung for buffalo flies)

Question 24

3. Animal control- reducing ectoparasites developing on animals

Answer 24

• chemical treatment (insecticide & acaricides) as prevention/repellent/kill or cure, quaranine
• Use genetically resistant hosts to reduce parasite burderns
• use older animals w more resistance to parasitism to control infested areas
• vaccines?