Pediculus - an ectoparasite

• how many species of lice are there?

  there are many species of lice and each parasitises its own host species - some are even so specialised as to be found on only one part of a host’s body
• do lice have wings?

  no
• how do lice move from one host to another and why do they move like this?

  lice can’t fly and their legs are poorly adapted to jumping and walking so they are transferred from one host to another by direct contact
• what happens if lice get removed from the human which they live?

  they die
• what are the 3 stages in the louse life cycle?

  • adult
  • egg
  • nymph
• what happens in the louse life cycle?

  • an adult louse lays eggs, which hatch after 1-2 weeks into nymphs, leaving nits, the empty egg cases
  • the nymph is like an adult, but smaller
  • it becomes an adult after about 10 days and, like adults, feeds on blood, which, in the case of head lice, is sucked from the scalp of the host