6.4.3 Arthropods Flashcards
What is veterinary entomology?
= study of INSECTS of veterinary importance
Arthropod classification
Insecta:
- Diptera (flies)
- Siphonaptera (fleas)
- Phithiraptera (Lice)
Arachnida:
- Aracina (ticks, mites)
Structure of insect body
Head
Thorax
Abdomen
Covered in hard exoskeleton
Structure of insect head
Capsule made of fused plates
Compound eyes
Simple eyes (ocelli)
Antennae (pair)
Structure of antennae
Varied
Structure of mouthparts
Basic structures common to all insects
great modification depending on feeding method:
Housefly - labellae (sponge like) to suck secretions/wounds
Mosquito - penetrates skin to feed on blood
Larval - hooks and cephalo-pharyngeal skeleton
Segments of insect thoracic
Pro-, Meso-, Meta- thorax
Structure of insect leg
Attached to body by COXA
Coxa, Trachanta, Femur, Tibia, Tarsus, Claw
Structure of wing
Membranous extension or integument, supported by veins
Discal cells = horsefly
Butchers cleaver cells = tsetse fly
Structure of insect respiratory system
Tracheae, spiricles, muscular contractions
Spiracles are mounted on a stigmatic plate
Structure of insect circulatory system
Heart - series of valves in a tube form aorta
Along top part of the insect
Structure of insect nervous system
Small brain, chain of ganglia, branching nerves
Along lower part of the insect
Structure of insect reproductive system
analogous to mammalian repro system
Spermatheca (female) - receptacle for sperm to keep viable for most of insects life
What are the 2 main life cycle types in insects? What’s the difference between oviparous and viviparous insects?
Most adult female insects are OVIPAROUS (lay eggs)
Some are VIVIPAROUS (lay larva or nymphs)
Two life cycles:
- Simple metamorphosis
- Complex metamorphosis
Explain a simple metamorphosis cycle
Egg > Nymph
Nymph moults (ECDYSES) into adult insect (IMAGO)
