Ctenocephalides felis - Cat Flea
Ctenocephalides canis - Dog Flea
Pulex irritans - Human Flea
What are fleas?
There are about 2000 species of fleas worldwide. The most common is the cat flea, Ctenocephalides felis. Fleas are small, wingless, ectoparasitic insects measuring between 1-8mm. They are laterally flattened with clearly segmented bodies and large hind legs adapted for jumping. They possess piercing and sucking mouthparts. Their colouring ranges from yellow to chestnut brown depending on the species.
Where do they live?
Fleas are not generally host specific. The cat flea, Ctenocephalides felis, can be found on a wide range of hosts from cats and dogs, through to camels and cattle. They are not adverse to biting humans and will happily live in association with them. There is, however, a human flea, Pulex irritans, which is quite rare and can also be found on a variety of hosts including badgers, pigs and foxes. Fleas can be found in the fur, feathers or sleeping areas of their hosts depending on the host's activity. In the home the cat flea is commonly found on both the cat, its bedding, or favourite area to lay in.
How do they breed?
The female flea will lay her eggs in either the fur or feathers of their host, or in the host's sleeping place. The eggs are very small, pearly-white and oval. These hatch after 2-3 days, once the first instar larva is ready to emerge. These larvae are tiny, white and legless about 1 to 2 mm long. They move on bristles found on each segment of the body.
The larva will feed on various organic debris, including the cast faeces of the adult fleas. This faeces contains protein from the adult fleas original blood meal which is necessary for the larvae to grow. The larvae go through three larval stages (or moults) before going on to pupate. When they reach this stage they spin silken cocoons out of dirt and other debris from their surroundings. The adult flea does not emerge from the pupa until it senses some form of vibration which alerts it to a much needed blood meal.
Why are they are problem?
Fleas are a biting nuisance and can cause a localised bite reaction, which is often inflamed and itchy. They can also lead to severe dermatitis if animals are subjected to prolonged infestation.
There are several products available on the market for the treatment of fleas. These include sprays for the animal, spot-on treatments, pills and flea powders. These can all be used in conjunction with eachother and also with flea sprays specifically designed for use in the home. Such sprays for the household contain insecticides, which act as insect growth regulators (IGR's) or insecticides, which are chitin inhibitors; both these insecticides prevent the flea larvae from reaching maturity. Household sprays are designed for use on carpets, upholstery and in areas where the animal sleeps e.g. pet bedding.