Understanding the flea life cycle to help plan control strategies

December 2, 2007

A basic understanding of the flea life cycle is really useful in planning a flea control strategy – and to assess when things are “on track” or when additional control measures may be required.

The flea lifecycle is a basic insect lifecycle which involves four major phases:

1. Flea eggs are laid onto the pet by adult female fleas. These fall off the pet into the environment where they hatch out as flea larvae – the highest concentrations of flea eggs are in areas that pets spend the most time such as bedding and rest areas.
2. Flea larvae are a small, white worm-like stage (about 5 mm long) which feed on debris from the dog or cat including flea dirt. Flea dirt is a nutritious meal for larvae because it is high in protein and not completely digested by the adult flea. They are not generally seen as they tend to leave deep in carpet pile or pet bedding. Once they have matured they spin a coocoon around themselves to form the pupal stage.
3. Flea pupae is the equivalent of the cocoon stage of a moth. The cocoon is very hard to kill with insecticides and is resistant to vacuuming because the pupae attach themselves firmly to carpet fibres and pets bedding. In the absense of a dog or a cat to feed on (such as when householders go on vacation), the pupal stage may become dormant for a long time – up to 150 or so days. This stage can also form a reserve of fleas which can infect the pets long after an effective flea control product has begun to be used. In order to hatch out of the cocoon, pupae need the right stimuli such as vibration and carbon dioxide from a passing pet. When this is present they hatch out and quickly jump onto the animal. In cases such as when the family has been on vacation and the house vacant – huge numbers of hungry immature fleas may hatch out at the same time and attach to pets and even to humans.
4. Once immature fleas have jumped onto an animal they begin to feed very quickly – normally within a minute of attaching to the animal. They will feed voraciously for the first 24 to 48 hours. This extended feeding is required to give them the protein and energy requirements for mating and laying eggs. Once a female flea has been on the pet for about 36-48 hours she is ready to lay eggs. She will lay about 20 eggs per day onto the pets coat for up to about 100 days – that’s about 2000 eggs for each and every female.

So what are some important flea control tips that we can learn from an investigation of the flea life cycle?

• If you wait until you are seeing many fleas before using an effective flea control product – you are asking for trouble. Every female has laid 20 eggs each per day so by the time you start treatment you already have an infested environmental. Start an effective flea control product BEFORE you expect to see fleas – before the weather really warms up!

• Don’t be surprised if you see fleas on your pets for some weeks (up to 8 weeks) after you first start using an effective flea control product – the pupal stage can exist without taking a blood meal for up to 100 days – so there may be a huge resevoir of pre-emergent fleas just waiting to jump onto your pet. All of the flea stages already in the environment must go through their life cycle and become immature adult fleas which infest your pet before they are killed.

• The pupal stage is very resistant to chemicals attack, so concentrating your efforts on using an effective ON ANIMAL flea control product will be much more effective than trying to control the life stages which are present in the environment.

• If your house or yard are full of fleas, don’t restrict the movement of your treated pet. If you are aware that there is a terrible flea problem in a bedroom where your pet sleeps, make sure you continue to let your pet go in there. An effectively treated pet becomes a mobile flea killer. If your pet is not allowed in an infested area then hungry fleas will look for an alternative source of blood – and that will either be you, your family or your friends.

• However, we also know that flea eggs will congregate where your pet spends most of his/her time – make sure you really concentrate on cleaning and vacuuming these areas.

• Make sure that you optimize your use of an effective flea control product. Ensure that you dose your pet adequately and follow all of the instructions on the product label.

Good luck with your flea control!

Posted in Flea facts