pulgasGeneral features

The order Siphonaptera – Siphon (a tube) + aptera (wingless) – is represented by the fleas. They are small, dark-coloured, flightless insects. Fleas have a flattened body laterally and have legs adapted for jumping. Their mouth parts are biting, causing great nuisance to the hosts. They are external parasites that, in the adult stage, feed mostly on the blood of mammals, although some species also have birds as host. The larvae feed on waste. There are over 1,000 known species.

Physiognomic traits

– Sucking, biting mouth apparatus
– Jumping legs
– Apterus
– Laterally flattened body


From the point of view of its development, the flea is holometabolous, i.e. it has a complete metamorphosis, passing through all the stages: egg, larva, pupa and adult. The female flea lays hundreds of eggs on its host; after one to two weeks these hatch, leaving the larvae that feed on waste remains; between two to three weeks, they weave a cocoon and pupate for an indeterminate period of time, when they detect a warm-blooded animal, they break the cocoon and jump towards it, which thus becomes the host, feeding on its blood.



A threat to public health

Fleas are vectors of bubonic plague. They were the major carriers of this pest in the Middle Ages, from the host rats.

Main species

– Pulex irritans (Man flea). Size: 2 to 3 mm. Laying: up to 400 eggs per female.
Lifespan: 19 months.
– Ctenocephalides canis (Dog flea). Size: 1.5 to 3 mm. Laying: 200 to 400 eggs per female.
Lifespan: 18 months.
– Ctenocephalides felis (cat flea). Size: 1.5 to 2.5 mm. Laying: 200 to 400 eggs per female.
Lifespan: 18 months.
– Xenopsylla cheopis (Mouse flea). Size: 1 to 2 mm. Spawning: 200 to 400 eggs per female.
Lifespan: 10 months.