Ectoparasites Flashcards
What are the characteristics of those organisms in the phylum ARTHROPODA
- chitonous exoskeletons
- Internal musculature
- separate sexes
- moults between stages
What are the classes under ARTHROPODA?
- Insecta (Diptera-flies, phthiraptera =lice, siphonoptera-fleas/other-cimex)
- Arachnida (A-,pro-, meso-stigmata (mites)/ metastigmata (ticks)
- other (crustacean/pentastomida)
What make up the class INSECTA?
flies (Diptera), lice (Phthiraptera), fleas (Siphonoptera) and other (bed bugs Cimex)
What is the anatomy of those that make up INSECTA?
- Head, Thorax (3 segments) and abdomen (8-10 segments)
- 3 pairs of legs
- 1 pair of antennae
- only arthropods to possess wings
How many legs do those organisms classified as INSECTA have?
6 always!
The order Phthiraptera refers to what?
lice (singular louse)
‘aptera’ means no wings
- dorsoventraly flat
What are the 2 suborders in the order Phthiraptera?
Arthropoda -> Insecta -> Phthiraptera
- Anoplura (sucking lice) = mouth parts penetrate skin feeding via sucking body liquids -> Topical insecticides less likely to work
- Mallophagia (Biting lice) = mouth parts are not penetrating skin. feeding on keratin and superficial layer of skin -> topical insecticides work
What are some characteristics of the sucking louse?
- Narrow/relatively elongated head (head evolved to pierce through skin and feeding on fluids)
- horse, pig, cattle, sheep, dog
- often specific to a site on a host
- v host specific
- cosmopolitan, increase in winter
- highly pathogenic
What are some characteristics of biting lice?
- “chewing lice” or “body lice”
- Broad and rounded head as wide (or wider) as the thorax
- Areas of fine hair
- smaller (<3mm)
- Pale in colour
- Keratin feeders
- Cosmopolitan
- dog, cat, sheep, cattle, horse, poultry
- generally less/non pathogenic but cause kyperkeratosis
- Bovicola ovis is in sheep fleece and affects wool growth and is of significant economic impact
Bovicola Ovis is what type of parasite?
Biting louse
What is the order SIPHONAPTERA commonly known as?
fleas
Characteristics of the order Siphonaptera:
- wingless (‘-aptera’)
- Feed by inserting their mouthpart directly into capillary and then “siphon” out blood
- laterally compressed
- 3rd pair of legs adapted for jumping
What flea is a major cause of skin problems in dogs & cats?
Ctenocephalides felis (Cat flea)
What is the most resilient stage of the flea life cycle?
- Pupa
Outline the lifecycle of a flea?
- female needs blood to lay eggs
- Eggs drop into the envt
- Maggot-like larva feeds on detritus (inc. flea faeces)
- Pupa = highly resilient stage
- Only 5% of fleas are on the host, 95% is in the environment (eggs, larvae, pupae)