2. fleas

Question 1

what is hemimetabola

Answer 1

simple metamorphasis, have nymph cycle
egg -> nymph -> adult

Question 2

what is holometabola

Answer 2

complete metamorphasis
egg -> larva -> pupa -> adult

Question 3

describe general anatomical features of insects

Answer 3

• head, thorax (where legs come from) and abdomen (where digestion occurs)
• exoskeleton
• spiracles for respiration (holes on side of body)

Question 4

describe the exoskeleton and its limitations

Answer 4

• made of chitin (polysaccharide and protein
• provides protection
• site of muscle attachment
• limit to absolute size
• limit to growth stage size

Question 5

what are siphonaptera

Answer 5

fleas
siphon - tube or pipe mouth
pteron = wing
aptera = no wings

Question 6

what are the physical adaptations of fleas

Answer 6

• tube like mouth parts
• laterally flattened with hard exoskeleton
• wingless
• backwards pointing spines and bristles to prevent being pulled off host
• enlarged hind legs for jumping

Question 7

what do fleas eat

Answer 7

• adult male and female are obligate blood sucking parasites
• rest of lifecycle lives off of dead skin cells (dust), fungi, microbes, etc)

Question 8

how doe fleas cause disease

Answer 8

• irritation
• allergy
• blood loss - anaemia
• spread of infections

Question 9

what fleas are you most likely to encounter in the UK and what are their preferred hosts

Answer 9

• ctenocephalides felis (cats)
• ctenocephalides canis (dogs)
• ceratophyllus gallinae (european hen flea)
• spilopsyllus cuniculi (rabbit flea)
• archaeopsylla erinacei (hedgehog flea)

Question 10

what type of flea is this and how can you tell

Answer 10

cat flea
The head slopes gently and is more elongated
than that of the dog flea. First spine of the genal
comb (arrow) is only a little shorter than the
second.

Question 11

what type of flea is this

Answer 11

dog flea

Question 12

describe the flea lifecycle

Answer 12

1. adult females lay eggs (1 per hour) which hatch in 1.5-6 days depending on temp
2. eggs often fall onto carpet or bedding
3. egg hatches into larvae, this stage lasts 15 days and they eat debris and flea dirt
4. larvae go into cocoon covered in environmental debris, takes 1 week to develop but can remain in pupa stage until environmental stimulai appropriate (warmth, vibrations)
5. hatch into adult

Question 13

discuss flea allergic dermatitis

Answer 13

• a common hypersensitivity reaction in cats and dogs
• significantly more likely to have signs of FAD when from multi pet households
• sensitised animals intermittently exposed to fleas appear to have greatest reaction (unlikely to find fleas on affected animal)
• sensitised animals constantly exposed to fleas have reduced reaction

Question 14

what common diseases are fleas vectors for

Answer 14

• myxomatosis
• bartonella henselae
• feline infectious anaemia
• plague
• typhus
• many more potentially (viral)
• dog tapeworm

Question 15

what are some consequences of routine flea treatment

Answer 15

environmental damage