ENTOMOLOGY


 Entomology & Nematology Department
 Prepared by Phil Koehler and Don Short*

 External parasites are generally found on or in
 the skin surface and are important pests because
 they bite or annoy both humans and their pets.
 Fleas, mange mites and ticks are the most fre-
 quently encountered and most troublesome pests
 which attack humans and their pets.

 FLEAS
 Fleas are small (1/16"), dark, reddish-brown,
 wingless, blood-sucking insects. Their bodies are
 laterally compressed, i.e. flattened side to side,
 permitting easy movement through the hairs on
 the host's body. Their legs are long and well
 adapted for jumping. The body is hard, polished,
 and covered with many hairs and short spines
 directed backward. The mouthparts of an adult
 flea are adapted for sucking blood from a host.
 Several species of fleas may be pests in Florida,
 and five kinds have been found on a single animal.
 The cat flea is the most frequently found flea, al-
 though the dog flea, human flea, and sticktight
 flea are also found in Florida. These fleas may at-
 tack a wide variety of warm-blooded animals in-
 cluding dogs, cats, humans, chickens, rabbits,
 squirrels, rats and mice.
 Biology
 The female flea lays her tiny, white eggs loosely
 on the hairs, in the feathers, or in the habitat of
 the host. The eggs readily fall off the host onto
 the ground, floors, bedding or furniture. Some
 fleas can lay 500 eggs over a period of several
 months by laying batches of 3 to 18 eggs at a
 time. The tiny eggs hatch in 1 to 12 days after
 being deposited. The white, worm-like larvae
 avoid light. They feed on particles of dead animal
or vegetable matter generally present in cracks


 ENT-6


 FLEAS,


 TICKS


AND MANGE


 Florida Cooperative Extension Service
 Institute of Food and Agricultural Sciences
 University of Florida, Gainesville
 John T. Woeste, Dean for Extension


and crevices. Within 7 to 14 days, unless food has
been scarce, the third larval stage is completed,
and the larva spins a tiny cocoon and pupates.
Usually after a week the adult fleas emerge and
begin their search for blood.
 Fleas are known to remain in the pupal stage
 from five days to five weeks in the absence of
 hosts. Adults emerge from the pupal case when
 vibrations from pets or humans let them know a
 host is near. This is one reason why people re-
 turning to an unoccupied home may suddenly be
 attacked by an army of fleas.
 Adult fleas must feed on blood in order to re-
 produce; however, adults can live for long periods
 without feeding. Fleas usually live and breed most
 heavily where pets rest. Persons coming near
 these resting places are also subject to attack. If
 fleas are established in a home, they will feed on
 man as well as on the pets. The usual places of
 attack are the ankles and lower portions of the
 legs.
 The so-called "sand-flea" is nothing more than a
common flea that is breeding outdoors in the soil.
Contrary to belief, fleas cannot go through several
generations without having a blood meal.
 The entire life cycle of a flea requires from
two weeks to two years. Hot wet summer months
favor egg laying. Hot dry periods give maximum
adult production so August to September usually
gives the greatest adult flea populations.

 Importance
 Fleas often breed in large numbers where pets
and other animals live. Pets infested with fleas
bite and scratch themselves constantly. Their
coats become roughened and the skin can become
infected. Symptoms of sensitized hosts are often


* Phil Koehler and Don Short are Assistant Professor and Extension Entomologist and Associate Professor and Extension Entomologist, respec-
 tively, Department of Entomology and Nematology, University of Florida, Gainesville.