Flea
Flea is the common name for any of the small wingless
insects of the order Siphonaptera . Fleas are external parasites, living by
hematophagy off the
blood of mammals and
birds, and genetic and morphological evidence indicates that they are descendants of the
Scorpionfly family
Boreidae, which are also flightless; accordingly it is possible that they will eventually be reclassified as a suborder within the
Mecoptera. In the past, however, it was most commonly supposed that fleas had evolved from the
flies , based on similarities of the larvae.
Encyclopedia
Flea is the common name for any of the small wingless
insects of the order
Siphonaptera . Fleas are external parasites, living by
hematophagy off the
blood of mammals and
birds, and genetic and morphological evidence indicates that they are descendants of the
Scorpionfly family
Boreidae, which are also flightless; accordingly it is possible that they will eventually be reclassified as a suborder within the
Mecoptera. In the past, however, it was most commonly supposed that fleas had evolved from the
flies , based on similarities of the larvae.
Note: There is also a genus of
foraminiferan Protozoa named
SiphonapteraSome well known flea species include:
In most cases, fleas are just a nuisance to their hosts, but some people and some animals suffer
allergic reactions to flea saliva resulting in
rashes. Flea bites generally result in the formation of a slightly-raised swollen itching spot with a single puncture point at the center. The bites often appear in clusters or lines, and can remain itchy and inflamed for up to several weeks afterwards. Fleas can also lead to hair loss as a result of frequent scratching and biting by the animal, and can cause anemia in extreme cases.
However, fleas can also act as a vector for disease. One possible example of this was the
bubonic plague, which may have been transmitted between rodents and humans. Murine typhus fever, and in some cases
tapeworms,
Hymenolepis, can also be transmitted by fleas.
Fleas
Fleas pass through a complete life cycle consisting of egg, larva, pupa and adult. Completion of the life cycle from egg to adult varies from two weeks to eight months depending on the temperature, humidity, food, and species. Normally after a blood meal, the female flea lays about 15 to 20 eggs per day — up to 600 in its lifetime — usually on the host . Eggs loosely laid in the hair coat drop out almost anywhere, especially where the host rests, sleeps or nests .
Eggs hatch between two days to two weeks into
larvae found indoors in and along floor cracks, crevices, along baseboards, under rug edges and in furniture or beds. Outdoor development occurs in
sandy
gravel soils where the host may rest or sleep. Sand and gravel are very suitable for larval development which is the reason fleas are erroneously called "sand fleas".
Larvae are blind, avoid light, pass through three larval
instars and take a week to several months to develop. Their food consists of digested blood from adult flea
feces, dead
skin,
hair,
feathers, and other organic debris; larvae do not suck blood.
Pupae mature to adulthood within a silken cocoon woven by the larva to which pet hair, carpet fiber, dust, grass cuttings, and other debris adheres. In about five to fourteen days, adult fleas emerge or may remain resting in the cocoon until the detection of vibration , pressure , heat, noise, or
carbon dioxide . Most fleas overwinter in the larval or pupal stage with survival and growth best during warm, moist winters and spring. "Flea season" is traditionally at the end of summer and in the early fall, but in warmer areas can last year round.
Flea
bites can be treated with Calamine lotion or 0.5-1% conc.
hydrocortisone cream. Lufenuron is a veterinary medicine that attacks the larval flea's ability to produce
chitin. See also Frontline .
References
External links
- from the Berkeley Parents Network
-
- An essay on the natural history of the flea
- Life cycle and control methods for fleas
