

Description



There are an estimated 1,600 species of fleas. Fleas are medically

important because of their worldwide distribution, abundance, and

irritating bites that can cause health problems. Fleas infest birds

and mammals, including people, and are abundant on rodents. The

most common flea on people in Delaware is the cat flea. Other fleas

such as dog flea, human flea, Oriental rat flea and several rodent

fleas turn up only occasionally as a human pest.



Adult fleas are small wingless insects, hard skinned, spiny,

flattened side to side (like fish) and black to brownish-black in

color. They range from 1/25-inch to 1/4-inch in length. Nature

designed fleas to move freely among the hairs and feathers of their

hosts. They are easily disturbed while feeding and may run or jump

away using hind legs especially adapted to jumping.



Life history and development



Fleas go through four stages of development: egg, larva, pupa, and

adult. Larvae are whitish, legless, blind, worm-like and less than

1/4-inch long when full grown. They are sparsely covered with

hairs. Pupae are enclosed in cocoons that become encrusted with

soil particles and lint. They resemble tiny dust balls. The egg,

larval, and pupal stages are rarely seen.



Mating usually takes place on the host animal, but not always.

Female fleas mate only once. They require a blood meal before they

can lay fertile eggs, and not all eggs are laid at once. Since eggs

are not glued or attached to the host, they can easily fall to the

ground or to the nest or bedding of the host. A female can lay 4 to

8 eggs after each blood meal, and several hundred during her life.



Eggs hatch into larvae in 2 to 3 weeks. Larvae feed on organic

debris such as hair and feathers, and especially the dried blood in

feces of adult fleas. They generally feed for about 9 to 15 days,

but can feed up to 200 days before forming inconspicuous cocoons in

which to pupate. The pupal period may last from 7 days to a year

FLEAS
before the adult stage is reached. Most fleas require 30 to 75 days
to complete a life cycle when proper moisture and warmth are
available. They suck blood and are able to survive several weeks
away from a host without feeding.

Vacationing families returning home may be greeted by large numbers
of hungry adult fleas. In fact, homeowners often first become aware
of flea problems after host animals have been removed from the
premises. In these cases the host pet either accompanied the family
or was housed in a kennel, so fleas that developed during the pet's
absence had nothing on which to feed. On reentering the premises
the pet owners become targets for the fleas' first blood meal.

Many people discovering fleas outside their dwelling mistakenly
call them "sand fleas." There is no flea by this name. Many kinds
of fleas, such as cat or dog fleas, develop in sandy places because
they were dropped there (as eggs or adults) by flea-infested
animals. Even a stray cat or dog sleeping on a doorstep or under a
porch may spread enough fleas or flea eggs to start an infestation.
This is especially true when strays sleep on a jute doormat.

Controls

Flea control involves management indoors, outdoors during the
summer and early fall and on the pet. In homes where pets are not
present you can spread sticky traps to survey for the exact
locations and to be certain fleas are, in fact, the problem insect.

It is important to locate where fleas are present inside. Try to
find adult fleas with sticky traps or by walking in likely areas
while wearing white socks. The adults will be evident on the white
fabric. 

Once you establish that fleas are present, clean the entire house
thoroughly using a vacuum cleaner. Be especially careful to vacuum
along baseboards, under furniture (move all furniture), areas where
pets sleep or rest, in cracks and crevices, and in all upholstered
furniture. Concentrate on areas where pets spend their time inside.
The vacuum bag containing fleas (larvae as well as adults and
pupae) should be destroyed or placed in a plastic bag and securely
tied, as soon as the house has been cleaned. You need to continue
this cleaning on a daily basis until fleas are no longer a problem.

Often a thorough cleaning although helpful, will not eliminate an
infestation. Usually the house will need to be treated with an
approved insecticide. The most effective insecticides for flea
control are labeled for professional use only, so you may need to
contact a pest control operator for treatment. The table lists
those materials that homeowners and PCOs can use to control fleas.

To treat an area yourself, move all furniture and spray all
carpeted surfaces as well as upholstered chairs, etc. Give special
attention to the bedding or sleeping areas of the pet.

In warm weather it may be necessary to control fleas in the yard or
at other outside areas. This can be done by the homeowner or by a
professional pest control operator (see table). You should plan to
cooperate fully with your PCO for best and most effective control.

It is also important to control the fleas that are on your pet(s).
Use a labeled dust or dip. A new dip and shampoo with a natural
ingredient called d-limonene and an active ingredient of citrus oil
is safe to use on young pets. It is also available as an aerosol
spray. Tick and flea collars also provide protection. Cats and dogs
vary in their sensitivity and acceptance of these collars. Consult
your veterinarian for the best advice regarding flea control on
your pet. Regular treatments of pets during the summer months
should protect pets and reduce the chances of flea problems developing.
Always check the product label for proper amounts, precautions and
limitations on usage.

Author:

Dewey M. Caron
University of Delaware 
Cooperative Extension Entomologist
11/90

To the best of our knowledge, all recommendations in this are in
accordance with those on product labels. However, if there is
disagreement between recommendations in this bulletin and what is
stated on the label, always follow the label directions.

Commercial companies or products are mentioned in this publication
solely for the purpose of providing specific information. Mention
of a company or product does not constitute a guarantee or warranty
of products by the Agricultural Experiment Station or Delaware
Cooperative Extension or an endorsement over products of other
companies not mentioned.
.
