You may be surprised to know that fleas are now often found in school buildings throughout the U.S. The most common species is the cat flea (Ctenocephalides felis) followed by the more rarely found dog flea (C. canis) and human flea (Pulex irritans.) The common cat flea is actually a threat to many mammals, as it is happy to bite and feed on humans, dogs and rodents as well as cats.
Everything You NEVER Wanted to Know About Fleas.
Fleas are small, wingless insects: they cannot fly, but instead, leap relatively long distances with their exceptionally strong back legs. Their lifecycle consists of four stages: egg, larva, pupa and adult. The eggs usually hatch within 2 to 12 days, with the larvae then developing over the next 8 to 21 days (remaining in the cracks and crevices where the eggs have originally fallen.) If conditions are unvaforable, the durable flea eggs can take up to 200 days to hatch. These larvae feed on old skin, hair and other organic matter. They’re especially fond of eating the feces of adult fleas, commonly referred to as “flea dirt.” Flea dirt is filled with blood that the flea larvae use for nutrients. Eventually, they form a pupa, lasting 1-2 weeks before emerging as an adult. Adult fleas emerge from the pupal case in response to the warmth, vibrations, and carbon dioxide coming from nearby animals or humans.
The newly hatched flea actively seeks out blood as soon as it hatches, although it can live 1 to 2 months without a meal. Fleas can survive 7 or 8 months after consuming just one meal.
How Do Flea Bites Affect Humans?
The adult flea will bite any human within reach. In humans, flea bites not only cause irritation but can also cause a severe flea bite allergy. Cat fleas can also transmit various diseases including: Yersinia pestis, which causes bubonic plague, Rickettsia typhi, which causes Murine Typhus, and Dipylidium caninum, the double-pored dog tape-worm, which can live in dogs, cats, or humans.
Controlling Flea Outbreaks in School Settings.
Even when pets are not present, fleas can become a problem in schools. Adult fleas can be carried from home on human clothing. Wildlife can transmit them, mainly to unused areas of buildings. Or, they may accumulate in and around the cages of pets kept in classrooms, basements, crawl spaces, attics, eaves, roof top structures and in shrubbery.
To check for the presence of fleas, a simple test can be carried out using a light trap. This small trap, comprised of a small electric light and sticky paper, attracts fleas who then become stuck to the paper. Studies has shown that fleas favor green light, particularly if the light is turned off for 10 seconds every 5 to 10 minutes. (Pickenset al. 1987) If the traps catch only a few fleas, the infestation is small. If 20 or more fleas are caught per trap in a week, this probably indicates a more serious infestation. An integrated management program will need to be implemented to eliminate the fleas.
Utilizing IPM for Fleas
There are a number of ways to reduce flea populations without resorting to pesticides or chemicals.
Floor areas with no carpeting and/or very badly infested areas, may require steam cleaning to thwart flea infestations. The steam kills adult and larval fleas however, since the warmth and humidity from the steam stimulates flea eggs to hatch a day or two after cleaning, some fleas may reappear. Again, vigilance is highly recommended.
It is suggested that Classroom pets be combed regularly with a special flea comb. If any fleas and eggs are removed from the animal they should be dropped into soapy water to kill them.
Leveraging Biological Controls to Fight Fleas.
You may wish to consider using biological flea control methods such as insect-attacking nematodes. These are microscopic, worm-like organisms which live in the soil and kill insects by entering their bodies, feeding on tissue and releasing harmful bacteria. These bacteria do not affect humans or other vertebrates. Once they have eaten the insect, they move on to the next prey. The nematodes sold for flea control are native to the United States and are found naturally in the soil all over the country, therefore do not pose any threat.
Another option is the use of Insect growth regulators (IGRs). These are used to stop the growth of the flea at or before the pupal stage, but they do not kill fleas that have reached the adult stage. IGR products, such as Methoprene and Fenoxycarb, should be used before fleas reach the adult stage and only in locations where severe infestations have previously occurred.
As a last resort where there are severe problems, you may need to use pyrethrins and synthetic pyrethroids. There are a number of flea control products containing these active ingredients.
With careful management, flea outbreaks on school campuses can be judiciously controlled.
* Image courtesy of Free Digital Images
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