07/26/2010
Its flea season -here are some facts on them . -------------------
Life cycle and habitat
Fleas are holometabolous insects, going through the four life cycle stages of egg, larva, pupa, and imago
(adult). The flea life cycle begins when the female lays after feeding.
Adult fleas must feed on blood before they can become capable of
reproduction.[3]
Eggs are laid in batches of up to 20 or so, usually on the host itself,
which means that the eggs can easily roll onto the ground. Because of
this, areas where the host rests and sleeps become one of the primary habitats of eggs and developing fleas. The eggs take around two days to two weeks to hatch.[2]
Micrograph of a flea larva.
Flea larvae emerge from the eggs to feed on any available organic
material such as dead insects, f***s, and vegetable matter. They are
blind and avoid sunlight, keeping to dark places like sand, cracks and
crevices, and bedding. Given an adequate supply of food, larvae should pupate and weave a silken
cocoon within 1–2 weeks after 3 larval stages. After another week or
two, the adult flea is fully developed and ready to emerge from the
cocoon. They may however remain resting during this period until they
receive a signal that a host is near - vibrations (including sound),
heat, and carbon dioxide are all stimuli indicating the probable presence of a host.[2] Fleas are known to overwinter in the larval or pupal stages.
Once the flea reaches adulthood, its primary goal is to find blood and then to reproduce.[5]
Adult fleas only have about a week to find food once they emerge, but
after that they can survive two months to a year between meals. Flea
populations are unevenly distributed, with about 50% eggs, 35% larvae,
10% pupae, and 5% adults.[2]
Their total life cycle can be as short as two weeks, but may be several
months in ideal conditions. Female fleas can lay 500 or more eggs over
their life, allowing for phenomenal growth rates.
Adult female rabbit fleas, Spilopsyllus cuniculi, can detect
the changing levels of cortisol and corticosterone, hormones in the
rabbit's blood that indicate she is getting close to giving birth. This
triggers sexual maturity in the fleas and they start producing eggs. As
soon as the baby rabbits are born, the fleas make their way down to them
and once on board they start feeding, mating, and laying eggs. After 12
days, the adult fleas make their way back to the mother. They complete
this mini-migration every time she gives birth.[6]