Introduction
The cat flea is the most common ectoparasite of both dogs and cats in the United States and has been found on over a dozen other animals. While it does serve as the intermediate host of some tapeworms, its main effect is the itching and irritation produced by its bite (along with flea allergy dermatitis in susceptible animals).
Appearance
Cat fleas are laterally-flattened, wingless insects approximately one-eighth inch long when engorged (double their unfed size). Under magnification they can be seen to have both genal and pronotal combs (ctenidia), differentiating them from most other fleas of domestic animals.
Biology And Behavior
Cat fleas have four stages in their development -- egg (Figure 1), larva (Figure 2), pupa and adult (Figure 3). The eggs, which are smaller than the period at the end of this sentence, are laid as the female feeds on the host and sift through the animal's coat to collect in the environment. The legless larvae which hatch from the eggs feed on excrement produced by the adult fleas and reach a length of about one-eighth inch. Outdoors these larvae develop in shaded soil and indoors they develop best in carpet. While under good conditions the larval stage takes only about a week, cool temperatures and low humidities can extend larval development for several weeks. The larvae spin cocoons of silk in which they incorporate debris from their environment (soil outdoors, soil and carpet fibers indoors) for pupation. The pupa develops and metamorphoses into an adult flea within this cocoon. This stage is the most variable in length as the pharate (pre-emerged) adult remains within the cocoon, sometimes for months, until signaled to emerge by such stimuli as pressure or carbon dioxide.
CREDITS: N. Hinkle, University of Florida
Figure 1. Cat flea eggs.
CREDITS: J. F. Butler, University of Florida
Figure 2. Cat flea larva.
CREDITS: N. Hinkle, University of Florida
Figure 3. Cat flea adult.
Footnotes
- This document is ENY-263, one of a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: March 1994. Revised: April 2003. Please visit the EDIS Website at http://edis.ifas.ufl.edu.
- N. C. Hinkle, Department of Entomology, University of Georgia, Athens, GA (formerly University of Florida student), P. G. Koehler, professor/extension entomologist, and F. M. Oi, assistant extension entomologist, Entomology and Nematology Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.