Phylum Arthropoda

Question 1

What are problems caused by Arthropods?

Answer 1

Introduction of venom
Allergic reactions
Invasion of host tissues 
Blood loss 
Vectors for pathogens

Question 2

What is the general Arthropoda Morphology

Answer 2

Body is divided into segments, contain an exoskeleton that functions for support and protection
Legs are jointed
Contain spiracles (insects) / stigmata or spiracles (mites and ticks
Separate sexes
Can be either Hemimetabolous metamorphis or Holometabolous metamorphis

Question 3

Define Hemimetabolous and Holometabolous metamorphis

Answer 3

Hemimetabolous metamorphis = Incomplete lifecycle, no difference in morphology, just size.

Holometabolous metamorphis = complete lifecycle, completely different egg to adult stages (egg, larvae, pupae, adult)

Question 4

What are the major differences between class arachnida and Insecta?

Answer 4

Arachnida = ticks and mites
Insecta = fleas, lice, flies 

Body segments = 2 (arachnida) vs 3 (insecta)

Locomotory appendages = 4 pairs of legs in adults and nymphs (arachnida) vs 3 paris (insecta)

Question 5

what is the Class Arachnida, Subclass Acari Morphology

Answer 5

Is all ticks and mites
2 segments:
- Gnathosoma (mouthparts: palps, chelicercae and hypostome)
- Idiosoma (rest of the body)

Adults and nymphs contain 4 pairs of legs, larvae contain 3 pairs

Leg sements = coxa - first leg segment which attaches to the body

Respiration is generally through openings called stigmata / spiracles. The stigmata can be associated with a groove called peritremes. The location of the stigmata is important for species identification

• Astigmata: through cuticle as no stigmata
• Prostigmata: opens at gnathosoma / shoulders
• Metastigmata: located behind the last pair of legs
• Mesostigmata: located at the levels of the 1-4th pair of legs

Question 6

What is the general lifecycle of the Subclass Acari?

Answer 6

Developmental stages = egg, larvae, protonymph, deutonymph, tritonymph and adult

Larvae contain 3 pairs of leggs

Question 7

What are the Orders within the Subclass Acari?

Answer 7

Astigmatia (mites) - No stigmata, cuticle
Prostigmata (mites) - stigmata at head
Mesostigmata (mites) - stigmata on abdomen
Metastigmata (ticks) - stigmata behind legs

Question 8

What is the morphological differences between ticks and mites

Answer 8

Mites:
- Smaller
Hypostome unarmed and hidden, microscopic

Fleas:
- Larger in size, macroscopic, hypostome armed with teeth, exposed