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Anterior end. The cat flea is cosmopolitan in
distribution and the genus is recognized for bearing
genal and pronotal
combs. The sloping forehead is the hallmark of C.f.felis. The
forehead of Ctenocephalides canis is more rounded. |
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Hind tibia. The distribution of setae on the hind
tibia supplies another diagnostic criterion.
Between the postmedian and
apical long setae on the trailing edge of the hind tibia
of
Ctenocephalides felis felis there is one notch that bears a short
stout spine. |
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Second instar cat flea larvae. The larvae of all
three instars feed principally on the feces of the adult flea which is
only slightly digested dried host's blood and, until the larva is about to
pupate, it
keeps its gut full of it. |
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Third instar cat flea larva. The larvae moults twice,
the final instar being about 5.0 mm long. At the end of its
development,
the larva empties the gut and spins a whitish, loose, ovoid cocoon,
and
becomes a pupa. |
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Cat flea pupae. When fully grown, the third instar
larva stop eating, empties its digestive tract, and
spins a silken cocoon.
In nature, such cocoons may be camouflaged with particles
of debris such
as sand grains and bits of flea feces, which tends to stick to the cocoon
and neatly encasing it. |
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Teased open pupal case showing one pupa in more advanced
metamorphosis. During the pupal period which lasts about a
week, the wormlike larva is almost
completely resorbed and made over into
the six-legged adult flea. |
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Adult flea removed from the cocoon. At the end
of the pupal period, a white, adult flea becomes recognizable in form
and
gradually darkens through tanning of its exoskeleton. |