Common Flea Species

There are many species of fleas but in the UK it is cat and dog fleas that cause most problems.

The main concern about fleas is usually the distress and discomfort that flea bites may cause you or your beloved pet.

Cat Flea

(Ctenocephalides felis)

Cat fleas are often unable to determine whether a host is suitable until it has been bitten. If it is deemed unsuitable, the flea soon drops off.

Ctenocephalides felis

Appearance

  • Cat fleas are 3mm long wingless ticks, flattened from side to side with long legs enabling them to jump.
  • They have both genal and pronotal combs (ctenidia), differentiating them from most other fleas of domestic animals.

Life Cycle

  • Fleas pass through four stages: eggs, larva, pupa, adult. The eggs are small and white. These stages combined vary from two weeks to eight months.
  • The adult flea is awakened by the detection of vibration of pet or human movement, pressure, heat, noise, or carbon dioxide for potential blood meals.
  • A cat flea cannot complete its life–cycle feeding only on human blood.

Habits

  • Cat fleas nest where the host is in its usual resting place, for example the cat basket. This is where the young often drop to mature.

Dog Flea

(Ctenocephalides canis)

Adult Dog fleas feed on the blood of dogs and cats, and they occasionally bite humans.

It is a vector of the Dog Tapeworm, Dipylidium caninum, which can also affect humans.

Dog Flea - Ctenocephalides carnis

Appearance

  • Adult is brownish black in colour, but appear reddish–black after a blood meal.
  • Adult dog fleas are 1 to 4 mm long. The legless larva is off–white and measures up to 5 mm long.

Life Cycle

  • The fleas go through a four–stage life cycle: eggs, larvae, pupae, adult.
  • The larvae are longer than the adults and feed on particles of dry blood, excrement, and organic substances.

Habits

  • The body is laterally flattened, which allows it to move easily through an animal’s fur. Spines project backwards from the body of the flea, which help it to hold onto the host animal during grooming.
  • As they can jump approximately 6 inches, they can move from host to host. They can also infest garden lawns.

Human Flea

(Pulex irritans)

Human fleas are now less common in the UK, except for farming areas where they can survive on pigs, and then jump to humans.

They will bite anywhere on the body and are associated with itchiness as fleas crawl over the skin.

Pulex irritans

Appearance

  • Fleas are black to brownish–black wingless insects. Adult fleas are 1 to 4 mm long.
  • They possess a long, fine proboscis which is used to pierce the skin of their host to feed on their blood.

Life Cycle

  • A female flea will lay 4 to 8 eggs after each blood meal, and can usually lay several hundred eggs during her adult life.
  • The smooth, oval light–coloured eggs measuring around 0.5 mm long, are deposited on, but not firmly attached to, the body, bedding, or nest of the host.
  • The adult generally emerges in a week or two after completing a larval and pupal stage, but under unfavourable conditions, the pupal period may be as long as a year.

Habits

  • Since they move from one host species to another, they present a risk of transmitting disease.
  • They are a known vector of Yersinia pestis (plague).
  • Human fleas can also be found on animals such as dogs, rats, pigs, deer and foxes.

Bird Flea

(Ceratophyllus gallinae)

Bird fleas can multiply enormously in hen houses, breeders, batteries and other similar environments.

Bird Flea - Ceratophyllus gallinae

Appearance

  • Adult bird fleas are generally brownish in colour, and 1–8mm long.
  • Their mouthparts are well adapted for piercing skin and sucking blood and project downwards from the head.

Life Cycle

  • They breed during the nesting period when the host and/or young are available for regular blood meals.
  • If the nest is reused, the pupae will hatch, mate and continue the breeding cycle.

Habits

  • Bird fleas can only live for a short time indoors and only in nests.
  • When the birds move from the nest, the adult fleas must find a new host.