Fleas in Winter? Understanding Flea Life Cycles and Prevention Tips

Imagine it is the dead of winter. The phone rings and it is your wife’s Aunt Polly from Minnesota. She wants to come and visit and stay at your house. A few days before her arrival you open up the guest bedroom, turn on the heat, vacuum the floors, and open the curtains. The room is all set to go. The next day you walk into the room and suddenly your legs are covered with little, dark-colored jumping bugs.

Fleas!

Where did they come from and why are they here?

The reasons for the sudden emergence of fleas in the dead of winter are determined by the unique life cycle of the flea. Fleas have complete metamorphoses. They go from an egg to a larvae, to a pupae or cocoon, to an adult. This process from egg to adult can occur in as little as 23 days or take up to a year.

The flea life cycle begins when the female lays eggs after feeding. Adult fleas must feed on blood before they can become capable of reproduction. The eggs are usually deposited on the host animal, which can be any warm-blooded mammal including humans. The female flea bites the host animal and takes a blood meal. This blood meal is deposited on the host animal as fecal material. Eggs and fecal matter are easily dislodged from the host animal, usually where they spend the most time.

The eggs hatch in about two days to two weeks into larvae. Larvae must eat the dried blood to survive. The larvae go through several molts or instars and become pupae. Larvae will become pupae in as little as a week or may take up to several months. In the pupae stage, the adult flea will lie in wait until conditions are just right. Adult fleas like vibration and movement. They also need a warm environment (70- 85 degrees F) with humidity of around 70 percent before they will emerge.

As one can see, fleas must have several conditions for them to be successful. They need a host animal, eggs, fecal material, a place to grow such as your carpet, and the correct environmental conditions. Disruption of any one of these conditions can be the demise of fleas in your own personal space. Simple vacuuming on a regular basis can remove fecal material and eggs and limit the flea population in your home.

Back to Aunt Polly’s visit and the occurrence of fleas in the spare bedroom. You may have had a previous infestation in the rest of the house that may have been controlled by flea spray, vacuuming, and treatment of the dog and cat. But that guest bedroom is seldom used, remains cold, and can be a perfect place for larvae and pupae to hang out and wait for the right conditions. These right conditions occur when the room is opened up, heated, and vacuumed, causing the dormant fleas to emerge and jump on you (but hopefully not Aunt Polly).

If you should find yourself with a sudden flea infestation, we at Koby recommend a flea treatment. Our flea treatments consist of treating the carpeting and surrounding areas with two separate but effective products. One of these products is a growth regulator, which disrupts the ability of the larvae to molt and advance into the pupae stage. Growth regulators mimic hormones that are already present in the environment. Another product that we use is an adulticide, which will kill adult fleas. Unfortunately, adulticides have very little effect on fleas in the pupae. We recommend vacuuming carpets prior to and after a flea application as this will stimulate the adults to emerge and come in contact with the product. Treatment of the dog or cat for fleas should be done around the same time as any treatment to your property.

Not everyone has Aunt Polly, but many people will find themselves with a flea problem.

Mike Kobus, Owner of Koby Pest Control in Placerville.