The life cycle
It is important to understand the flea lifecycle in order to obtain good control of this pest and to be aware of limitations some treatment methods will have.
The adult flea
The Flea Adult is the only Lifecycle stage which feeds on blood. When someone is experiencing flea bites in the home or workplace, it is obvious there are Adult Fleas present. Immediately after a flea has completed a blood feed from the host, it will utilise the nutrients and begin laying eggs. This will occur very quickly the Flea will lay many eggs at one time. A couple of thousand Flea eggs may be laid by a single flea in the full course of its life!
The flea egg
Flea Eggs are smooth and white. A flea can lay about 50 a day after a blood feed. Following gestation an egg will hatch into larvae in less than one week.
The Flea larvae
The Flea maggot is very small and difficult to see. They will not be obvious usually as they will remain out of sight, hidden in crevices between floor boards, carpet edges, vinyl seams and edges and mattress and furniture folds. Larvae feed of flea faeces and other biological matter.
The final larvae stage of the Flea is the Pupae. A highly protective cocoon in which the adult flea emerges when disturbed. Vibration or heat can signal the flea to emerge and jump on to its first host. This can occur any time after a week in the cocoon! However fleas can lay dormant in this pupae stage for up to a year if undisturbed such as in a vacant house of building.
Flea control products such as broad spectrum pyrethroids, organic phosphates and carbamates all which are frequently used for flea control, only kill adult fleas. This is why often there is a dead zone for a couple of weeks before activity can start again after the first treatment.
Insecticides cannot control the larvae, eggs or pupae stage.
Because adult fleas only make up 5% of the total flea population, larvae and eggs making up for the other 95%, insecticide sprays will kill not much more than 5% of the entire population, leaving the eggs and larvae to continue to morph eventually into adult fleas.