Fleas are external parasites that live by feeding on blood from mammals and birds. Adult fleas are very small insects (about 1/16” to 1/8” long), dark reddish-brown and wingless. They are compressed from side to side allowing easy movement through the fur, hair or feathers of their host. They have three pairs of legs, and their longer back legs make them excellent jumpers. Fleas can jump thirteen feet horizontally and seven feet vertically. The flea’s body is hard and covered with hairs and spines projecting backward, and they have a piercing-sucking mouthpart used to obtain blood meals from a host.
Types Of Fleas
The most frequently found flea in the world is the cat flea (Ctenocephalides felis). Its primary host is the domestic cat, and it is also the most common flea found on domestic dogs. There is also a dog flea (Ctenocephalides canine) which looks like a cat flea but is not as common. Sticktight fleas (Echidnopaga gallinacea) can become problematic when pets frequent areas near poultry. These fleas attach themselves to the host’s eyes and ears. Other popular fleas are the human flea (Pulex irritans), the northern rat flea (Nosopsyllus fasciatus) and the oriental rat flea (Xenspsylla cheopis).
Flea Life Cycle
A flea’s life cycle consists of egg, larva, pupa and adult, and the entire cycle can vary from two weeks to eight months depending on species, humidity, temperature and food. (The life cycle of a cat flea up to adulthood at room temperature takes about eighteen days.) Normally, after the female has a blood meal, she will lay between fifteen to twenty oval, white eggs per day on the host. Once the eggs dry they will usually drop off the host where it rests (carpet, upholstered furniture, cat or dog boxes, etc.). Eggs hatch into white, worm-like larvae in two days to two weeks.
The flea larvae phase consists of three stages, which last a week to several months. The larvae mostly feed on the dried blood found in the fecal matter of the adult fleas which falls off the host. Larval development normally occurs in places where there is at least 75% humidity, and larvae develop more quickly in warmer temperatures (70? to 90?F).
Once the larval stage is completed, the larva spins a tiny, silken cocoon and pupates. The pupae is usually camouflage by local debris. The larva will mature to adulthood inside its cocoon in about five to fourteen days. Since the new flea can only live a week without a blood meal, it will remain in its cocoon until it detects a host through vibration (people or pets walking), pressure (a host laying down on them), noise, heat or carbon dioxide. This is one reason why a family returning to an unoccupied home after an extended period of time (a long vacation) may suddenly be attacked by a massive amount of fleas. Newly emerged fleas will jump on a host only minutes after leaving their cocoon and begin feeding. An adult cat flea will normally live for thirty to forty days.
Habits Of Fleas
Fleas often breed most heavily where pets and other animals rest. Fleas may be found on pets throughout the year, but tend to be most problematic during spring and early summer. Pets infested with fleas are incessantly biting and scratching themselves. Humans are affected by flea bites differently depending on their sensitivity to the flea saliva. Fleas tend to bite humans on the ankles or lower leg and leave a small, red, itchy bump. People with allergies to the saliva, or flea allergic dermatitis (FAD), will experience extreme itching, and often a secondary infection is caused by the constant scratching.
Adult fleas are not only a nuisance to animals and humans, but they can cause serious medical problems. Pets with flea allergies (FAD) will have intense itching and may experience skin irritation and hair loss. Cat fleas and dog fleas may be intermediate hosts for the dog tapeworm. Both cats and dogs can acquire tapeworms while grooming themselves and ingesting a flea infected with a tapeworm cyst. Even children have been known to pick up tapeworms by accidentally consuming an infected flea. Fleas may even transmit the bubonic plague or murine typhus fever to rodents which in turn may pass it to humans.
Additional General Information
1) The single primary deterrent of egg production is the grooming habits of the pets. Cats are the best groomers and they ingest up to 50% of the fleas on them.
2) The larva stage of the life cycle is typically 7 to 11 days.
3) The larva undergoes a huge change in body size in five to six days and during its life cycle spins a silk cocoon.
4) The larva can crawl up to three feet in distance.
5) In order for the Cat flea to survive, it must have a minimum of 30% humidity. The larva is negative phototaxis, which means it does not like light. The larva is also positive geotaxis, meaning it moves downward. These are two reasons why larva are found in the base of carpets.
6) The primary reason flea infestations vary is the amount of humidity. Carpet helps protect the humidity surrounding the larva.
7) Larvae develop best at 72 degrees temperature and 78% relative humidity.
8) The pupa typically develops in one to three weeks, however, can be in the cocoon up to 140 days or longer in laboratory tests.
9) The pre-emergent adult will stay in the cocoon until impacted by the appropriate heat, carbon dioxide, movement, or light intensity. !It can emerge from the cocoon in less than 1 second.
10) If a pet or human passes closely to a flea pupa, the pre-emergent adult will see a difference in light intensity, sense movement, feel the heat from the body, or recognize carbon dioxide. All of these events indicate the presence of a food source. They emerge quickly due to their need to get to a food source.
11) Female fleas develop faster than male fleas while in the cocoon.
12) There are approximately 2.1 to 2.2 times as many female fleas as male fleas.
13) The female flea consumes up to 15 times its weight in blood.
14) Eight to nine minutes after an adult feeds it will have a fecal discharge” which is what the larvae eat.
15) Fleas survive through the winter microcosms which are conductive to flea life. They also live through the winter on such outside animals as possums and raccoons.