Drugstore Beetle

Order: Siphonaptera
Family: Pulicidae
Genre: Ctenocephalides, Pulex

Identification & Life History:

This is the season of being indoors and many of our pest problems follow us inside. This month, fleas are on my mind, in my house and biting my ankles.

There are many kinds of fleas, about 2,000 worldwide, and all require a blood meal from a mammal or bird. Fleas have a complete life cycle, meaning they go through egg, larval, pupal and mature adult stages. Adult fleas are easily recognized and the most common stage that is found. Adults are spiny and brown. The body of adult fleas is strongly flattened laterally with long legs made for jumping. Both sexes feed on blood but the female requires the blood meal to produce an egg brood. Depending on the species, adult fleas may stay on the host (such as cat fleas) or leap off after feeding.

Adult fleas are known for their amazing acrobatic feats and their amazing strength, but they also are impressive breeders. On an average rate, fleas lay one egg per hour. Adult fleas can live from 4 to 40 days. You do the math! Eggs of fleas are small (about 0.5mm) white and oval. Eggs drop off the host, usually in areas where the host sleeps (like a dog blanket, carpet, couch). After a couple of days, eggs hatch into small white grubs. The grubs eat protein debris and the fecal pellets dropped by the adults after a blood meal. Even being a lover of biology, I do have to admit that this has to be one of nature’s more disgusting life cycles.

These small, legless, eyeless grubs develop and pupate within 4 to 15 days depending on the species, temperature and humidity. Once larval development is complete, fleas enter the pupal stage, which can last up to 12 months, also depending on temperature and other environmental factors. The pupating larvae tie up debris to hide the cocoon. Adults hatching from the cocoon can be stimulated by compaction or disturbances such as walking or shaking the ground. Under room temperatures, the entire life cycle of a flea may be completed in 18 days.

Damage & Monitoring:

Historically, fleas have been serious transmitters of disease such as the bubonic plague, Black Death. Other diseases include murine typhus and tapeworms. Nowadays, fleas are generally annoyance pests. Fleas bite our pets and us, causing red welts or spots and major irritation. Some pets and people can have sensitive reactions to bites and develop allergic dermatitis. In general, fleas cause a lot of irritation, scratching and some blood loss.

Most people monitor fleas by checking their pets or by watching them jump up onto your socks as you walk through an area. There are flea traps commercially available that use light to attract and trap adult fleas. Simple, regular grooming of your pets is the most reliable way to monitor. Look in places that are hard to reach for your dog or cat, such as ears or the lower belly. Look for the dried blood pellets left by the adults. If adult fleas are found, drop them into water because they can be difficult to squish between your fingers. Flea combs are available at pet stores for fine grooming and removal of flea adults. This is probably the preferred method of monitoring by your pet.

Management:

Integrating different pest management tactics is the only way to reduce and prevent flea problems. For example, if you only manage fleas occurring on your pet using flea dips, there will be many more emerging from the carpet to replace them. Management needs to take in consideration the flea’s biology. Management efforts should take place indoors, outdoors (to a lesser degree) and on the pet itself. For outdoor prevention, mow grass regularly and manage weedy borders where your pet spends time lounging. Reducing the local humidity in areas where your pet hangs out may reduce survival of the larvae.

Management indoors should be focused on sanitation. Because fleas are nesting parasites, regularly vacuum the area where your pet sleeps and spends the majority of time. For dogs, this could be a dog rug or kennel. For cats, it could be someplace that might not be as obvious, such as on top of the refrigerator. Vacuuming can remove some of the eggs, larvae, pupae and adults. Follow your pet around and see where they spend most of their time. Vacuum thoroughly and frequently. Wash or dispose of pet linens, such as dog blankets or rugs.

There are various insecticides registered for flea control in the home. Many of these products contain a mixture of active ingredients, chose one that contains an Insect Growth Regulator (IGR). These insecticides can be slow acting but are very effective. IGR’s disrupt the life cycle of fleas and do not allow them to develop into biting adults. Flea bombs are not the ideal way for treating flea problems; flea bombs disperse the insecticide into many other areas where fleas do not occur. Directed aerosol sprays treat only the suspect area and result in better coverage in tight places. Treat areas where your pet spends a significant amount of time. As always, be sure to read and follow the labeled directions carefully.

Regular bathing of your pet will reduce the population of fleas on your pet, however this can be a major chore depending on how your pet feels about bathes. On-the-pet treatments come in many different forms: shampoos, dips, dabs, rinses, powders, sprays, pour-on’s, foams, and pills. Chose one that best fits you and your pet; consult your veterinarian about specific recommendations. Flea collar’s containing insecticides do not offer much control; avoid prolonged, unnecessary exposure to insecticides. Many on-the-pet insecticides are relatively safe but reading and following the label is paramount when treating your pet.

Here in the PNW, we spend a lot of money trying to get rid of fleas. Keep in mind that fleas have also brought us joy and good deals through flea circuses and flea markets. Fleas should also bring us Pacific North Westerners a sense of pride. We are home to the largest flea in the world, measuring in at almost 1/3 of an inch! Luckily these fleas are specific to the mountain beaver.

To learn about fleas and flea management visit: http://gardening.wsu.edu/library/insemisc/fleas.htm.