PART 6: ARTHROPODA
Class Order Popular name
Insecta (insects) Phiraptera Lice
Hemiptera Bugs
Siphonaptera Fleas
Diptera Flies
Arachnida (spider-like) Acari Mites, ticks
Arthropods make up 85% of all animals. They have different harmful effects: stinging, poisoning,
vectors of diseases, food contamination, allergy, invasion of tissues,… They also can be parasitic for
plants which can have a big economic importance. Aptera = no wings
Transmission can happen in different ways:
- Mechanical: contamination (e.g. fly biting host and then biting another host: transmission)
- Biological
o Propagative Replication inside vector
o Cyclo-propagative Development & amplification in vector (e.g. malaria)
o Cyclo-developmental Development, no amplification in vector (e.g. filarium worm)
o Transovarial From female arthropod to offspring (e.g. Babesia, Dengue)
GENERAL MORPHOLOGY
1. Bilateral symmetry
2. Presence of coelome, complete digestive system
a. In coelome also haemolymphae: functions as blood and lymphae (immunity)
3. Segmented body parts: head – thorax – abdomen or cephalothorax (lice & mites)
4. Articulating legs (arthro-pods)
a. Femur, tibia and tarcus (landing on host and special adaptions)
5. Separated sexes
6. Chitin exoskeleton: sclerites (plates) ecdysis (shedding)
a. = protection against dehydration & physical insults
b. Dorsal: tergum Ventral: sternum
c. Lateral: pleuron
d. Sometimes needs to be flexible for uptake of blood
1
, GENERAL STRUCTURE
1. ARACHNIDA ACARI: MITES & TICKS
Large
= soft ticks
= hard ticks
Free living mites. Mainly problem for poultry
= follicle mites: commensal
= chigger / harvest mites -> scrub typhus
allergic airway problems
Scabies: inflamm. & itch
- Hard ticks have a
scutum, soft ticks don’t Small
- Nymphal stage differs:
o Hard ticks: 1 nymphal stage
o Soft ticks: mostly 3, sometimes 4 nymphal stages
- Stigmata = openings on the skeleton to elastic tubes which foresee oxygen to flight muscles
o Where you find the stigmata on the bodies of the acari determines the order
o Astigmata exchange oxygen through the cuticula
2
Class Order Popular name
Insecta (insects) Phiraptera Lice
Hemiptera Bugs
Siphonaptera Fleas
Diptera Flies
Arachnida (spider-like) Acari Mites, ticks
Arthropods make up 85% of all animals. They have different harmful effects: stinging, poisoning,
vectors of diseases, food contamination, allergy, invasion of tissues,… They also can be parasitic for
plants which can have a big economic importance. Aptera = no wings
Transmission can happen in different ways:
- Mechanical: contamination (e.g. fly biting host and then biting another host: transmission)
- Biological
o Propagative Replication inside vector
o Cyclo-propagative Development & amplification in vector (e.g. malaria)
o Cyclo-developmental Development, no amplification in vector (e.g. filarium worm)
o Transovarial From female arthropod to offspring (e.g. Babesia, Dengue)
GENERAL MORPHOLOGY
1. Bilateral symmetry
2. Presence of coelome, complete digestive system
a. In coelome also haemolymphae: functions as blood and lymphae (immunity)
3. Segmented body parts: head – thorax – abdomen or cephalothorax (lice & mites)
4. Articulating legs (arthro-pods)
a. Femur, tibia and tarcus (landing on host and special adaptions)
5. Separated sexes
6. Chitin exoskeleton: sclerites (plates) ecdysis (shedding)
a. = protection against dehydration & physical insults
b. Dorsal: tergum Ventral: sternum
c. Lateral: pleuron
d. Sometimes needs to be flexible for uptake of blood
1
, GENERAL STRUCTURE
1. ARACHNIDA ACARI: MITES & TICKS
Large
= soft ticks
= hard ticks
Free living mites. Mainly problem for poultry
= follicle mites: commensal
= chigger / harvest mites -> scrub typhus
allergic airway problems
Scabies: inflamm. & itch
- Hard ticks have a
scutum, soft ticks don’t Small
- Nymphal stage differs:
o Hard ticks: 1 nymphal stage
o Soft ticks: mostly 3, sometimes 4 nymphal stages
- Stigmata = openings on the skeleton to elastic tubes which foresee oxygen to flight muscles
o Where you find the stigmata on the bodies of the acari determines the order
o Astigmata exchange oxygen through the cuticula
2
