Siphonaptera

• Siphonaptera


  Order of fleas
• Fleas

  • Wingless insects with laterally compressed bodies
  • Abdomen has 10 segments
  • Legs are long, strong and adapted for leaping or jumping
  • Adults do not usually travel long distances without a host
  • Prefer to wait and jump onto a passing animal
  • Remain on the host until dislodged or groomed
• Without a host, adult fleas live only a few days to 2 weeks
• Fleas on short-haired cats and dogs

  Survive an average of 8 days
• Fleas on long-haired animals

  Live longer
• Male fleas


  • 9th abdominal segment bears the sensilium or pygidium, a dorsal plate
  • Tergum of 9th abdominal segment is modified to form claspers
  • Penis (aedegus) is chitinous and coiled
• Cat fleas are the most common fleas on dogs and cats
• Animals that cat fleas infest

  • Dogs
  • Cats
  • Raccoons
  • Opossums
  • Coyotes
• Animals that fleas are parasites of

  • Dogs
  • Cats
  • Pigs
  • People
  • Rodents
  • Rabbits
  • Birds
• Adult fleas lay up to 50 eggs per day on the pet
• Flea eggs fall off the animal into carpeting, beneath furniture cushions, and wherever the pet rests, sleeps or spends time
• Copulation in fleas occurs after a blood meal
• Flea larva


  Resembles a maggot or tiny caterpillar and feeds on organic debris including adult flea feces containing dried or partially digested blood
• Flea larvae cannot survive without feeding on organic debris, although they may also feed on organic matter such as food particles, dead skin or feathers
• Flea pupae


  Remain inside the cocoon for 2 to 4 weeks, sometimes longer
• Pupae are resistant to insecticides, which is why some adult fleas are seen for an extended period even after treatment
• Adult fleas emerging from cocoons

  Emerge 3-6 weeks after the eggs are laid, or a week or two after the pupa becomes an adult
• Adult fleas can remain in the cocoon for up to 5 months, but emerge within seconds when stimulated by a passing animal
• Cat fleas do not normally live on humans, but do bite people who handle infested animals
• Flea bites


  Cause small, red, itchy bumps, usually on the ankles and lower legs
• Allergic reactions to flea bites

  • Hives, rashes, itching
  • Typically appear 12-24 hours after a bite and may last a week or more
• Both male and female fleas feed exclusively on blood and may live up to 12 months
• Flea life cycle

  • Passes through four stages: egg, larva, pupa, and adult
  • Usually 3 larval instars, but only 2 in Tunga penetrans
• Adult fleas rest in the cocoon for a long time (up to 6 months) before emerging
• Adult fleas

  • Brown, wingless, laterally flattened, 1-6mm long
  • Jump away if there is a risk of being caught
  • React super-sensitively, making multiple punctures during a single blood meal
• Ctenocephalides canis and C. felis felis


  • Have both genal (cheek) and pronotal (on first thoracic segment) combs or ctenidia
  • Bases of genal teeth lie on a line parallel to the long axis of the head, distinguishing them from some other flea genera
• Echidnophaga gallinacea (poultry sticktight flea)


  • Sticks to the host like a tick and jumps like a flea
  • May be found firmly attached in clusters on chickens' heads, eyelids or in the ear canals of dogs, cats and other animals
• Where Echidnophaga gallinacea can be found on the host

  • Chickens' heads
  • Eyelids
  • Ear canals
• Echidnophaga gallinacea is firmly attached in clusters on the host
• Tunga penetrans


  Not host-specific, attacks many warm-blooded hosts
• Tunga penetrans

  Closely related to Echinodnophaga
• Tunga penetrans


  • Narrow thoracic tergites, shared with Echinodnophaga
• Xenopsylla cheopis


  • Has a vertical rod on the mesothorax
• Xenopsylla cheopis is the biologic vector of plague (Yersinia pestis) and endemic typhus (Rickettsia typhi)
• The vertical rod is lacking in Pulex irritans
• Pulex irritans


  • Six long legs and three thoracic segments
  • Found on humans and many other hosts, especially foxes
• Pulex irritans life cycle

  1. Female lays up to 450 eggs

  2. Eggs develop into pupae in 14 days

  3. Pupae give rise to adults in 7-10 days

  4. Adults can wait inside puparium for up to half a year
• Pulex irritans are proven vectors of agents of plague, erysipeloid and the tapeworm, D. caninum
• Adult fleas can live for a few days to 2 weeks without a host
• Fleas survive on short-haired cats and dogs for an average of 8 days