Fleas and Their Control
Guide G-317
L.M. English,Extension EntomologistCollege of Agriculture, Consumer and Environmental Sciences New Mexico State University
This Publication is scheduled to be updated and reissued 4/03.Fleas are small insects that appear flattened from side to side. They have piercing mouthparts and infest the hair coats of mammals and plumage of birds. Over 2,400 different species exist worldwide; fortunately, only a few species are important to humans. The side-to-side flattening of fleas bodies and their stiff bristle hairs, or setae, allow fleas to move quickly and make them difficult to remove from hair coats of pets. The most common species in New Mexico is the cat flea (Ctenocephalides felis)which feeds on cats, dogs, rodents, skunks, raccoons, and other animals. Less-common fleas found in New Mexico are the dog flea (C. canis) and the human flea (Pulex irritans).
These small, wingless insects pass through four developmental stages: egg, larva, pupa, and adult. A female flea can lay about 25 eggs per day for at least three weeks directly on the host or in the host's bed or nest. Eggs laid directly on the host usually fall off and can accumulate in rugs, carpet, dust, floor cracks, or damp soil. Eggs usually hatch within 2 to 12 days. Ideal conditions for flea egg hatching and larval development is between 65-80 degrees F with relative humidity of 70% or greater. Extremely dry conditions with temperatures over 95 degrees F usually kill larvae.
Under ideal conditions, flea larvae develop in 8 to 21 days in cracks and crevices where eggs have fallen. However, if conditions are less than ideal, larval development can take as long as 200 days. The larvae diet consists of dried blood excreted from adult fleas. Fully developed larvae then pupate.
The flea's pupal stage lasts one to two weeks under favorable conditions. However, when conditions are cool and moist, this stage of the insect's development can last nearly a year. An adult flea emerges from its pupal case in response to warmth, vibrations, and carbon dioxide from host animals or humans. The flea's ability to stay in the pupal stage until a host arrives can result in a sudden outbreak of adult fleas; they have been collecting as pupae and suddenly find a suitable host. When an adult flea emerges, it searches for a blood meal. Adult fleas can live one to two months without a blood meal and seven to eight months with a blood meal.
A flea infestation can be much more than a simple nuisance. Flea bites can cause skin irritations as well as serious allergies in pets and humans. Even more seriously, fleas can carry devastating disease organisms such as Yersinia pestis,the casual agent for bubonic plague; Rickettsia typhi,the causal agent for murine typhus; and Dipylidium caninum,the double-pored tapeworm.
Fleas can be a problem in urban residential areas. Occasionally, a problem exists in nonresidential buildings where feral dogs, cats, skunks, rodents, or urban wildlife reside. Flea management or control lends itself well to urban integrated pest management practices.
Monitoring infestations is necessary in any flea management program. Monitoring indicates whether fleas are present. The traditional method of sampling for a flea infestation is the "white sock test." A person walks through the suspected infested area with knee high white socks for a certain length of time and counts the fleas that jump on the socks. While it is quick and easy, the results are questionable. Other more reliable methods include a hand-held vacuum device with a handkerchief inserted into the dust bag and a variety of light trap devices developed to help monitor and control fleas. Cat fleas will orient toward specific light wave lengths and are more attracted to lights that are suddenly and temporarily interrupted. Properly designed light traps can be effective monitoring tools and control devices.
Persistent flea problems in buildings where there are no pets may indicate the presence of feral cats, rodents, or other wildlife. In this case, the wildlife must be removed and kept out to obtain flea control.
Thorough vacuuming on a regular basis keeps developing flea populations low by picking up adult and egg-stage fleas. The vibration caused by the vacuum cleaner will stimulate pupal-stage fleas to emerge and newly emerged adults may be picked up with the next vacuuming. While vacuuming is not very effective in picking up flea larvae in carpeted areas because they coil themselves around carpet fibers, vacuuming will pick up the dried blood they use as food. Where possible, use the vacuum attachments to vacuum cracks and crevices. Then use caulking or sealant to permanently seal these areas. Most fleas are killed when the dust in the vacuum bag blocks their breathing tubes, but to make sure, add one tablespoon of corn starch to the vacuum bag. Vacuum badly infested areas daily until infestation is controlled.
If infestations are extremely severe, steam cleaning and other controls may be needed. Steam-cleaning kills adults, larvae, and some eggs. However, the steam-cleaning stimulates the remaining eggs to hatch and some fleas may appear. Removable floor coverings, such as rugs, in infested areas should be washed. Wash household pet bedding regularly.
High heat kills fleas. Research shows that cat flea larvae die after being exposed to 103 degrees F for one hour. Some commercial devices have been developed to provide lethal temperatures. However, with this method fleas may burrow down in the carpet or upholstery and escape.
Outside organic matter can temporarily harbor flea larvae. Either dry these areas completely or flood with water to kill flea larvae and eggs. These areas also can be treated with insect-attacking nematodes or insecticidal soaps.
Purchase insecticidal soaps in pet stores and hardware stores. Some of these products contain 0.01% pyrethrin and can be used on pets, rugs, floors, and other places where flea larvae and eggs may have collected.
Insecticidal dust containing diatomaceous earth and silica aerogel, which is occasionally spiked with pyrethrins, can be used for flea control. Diatomaceous earth is made from fossilized diatoms and silica gel is a sand product. These products kill insects by rupturing their skins and absorbing oil and moisture. This causes dehydration and death.
Citrus oil extracts, d-limonene, and linalool are citrus-peel extracts. Products that contain these products kill all stages of fleas, while those containing only d-limonene kill only adults and larvae. These products can be applied directly to pets or animal bedding.
Borates, specifically sodium polyborate, can be used in carpeting to control flea larvae. This powdered material is worked into the carpet nap and then thoroughly vacuumed. This treatment can continue to kill flea larvae for up to one year. Some veterinarians sell sodium polyborate formulations for carpet applications and some pest control companies provide this service.
Acknowledgement: Thanks to Patricia Aaron, Extension Home Economist, for her help in editing this publication.
Table 1. General IPM strategies for an indoor flea control program.
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Table 2. Flea control products.
Pesticide
Ortho products:
Americare products:
Basus products:
EctoGuard products:
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Comments
Note: For heavy flea infestations in the home or yards, it is often advisable to employ a pest control company. Also, before applying any insecticide on a carpet, read the product label carefully for comments or warnings about potential staining. Vacuum carpet thoroughly prior to treatment and discard used vacuum cleaner bag. Note: (1) Methoprene foggers aid in control of larvae (not for control of adults unless label states it contains an adulticide). If only a methoprene fogger is used, an adulticide treatment may be needed in 7 to 14 days. (2) Insect Growth RegulatorsÑproducts containing methoprene and fenoxycarb are highly recommended as part of a flea control program. Apply Ortho, Americare, Basus, and EctoGuard products per the label(s) and note precaution statements. Program (lufenuron). This Ciba product is available through veterinarians for use as a once-a-month tablet/feed additive for pets. Female fleas that feed on the blood of treated pets do not produce viable young. Note however, supplemental treatment of the home or other areas frequented by pets usually is needed to obtain complete control. |
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Printed April 1998Electronic Distribution May 1998