Morphology

Fleas are dark brown in colour, wingless and possess a laterally compressed chitineous abdomen (Soulsby, 1982). The glossy surface of the body allows easy movement through hair and feathers (Urquhart et al., 1987). Compound eyes are absent, but some species have large or small simple eyes. The legs are long, strong and adapted for leaping (Soulsby, 1982). This can especially be seen in the third pair of legs which is much longer than the others (Urquhart et al., 1987) and muscular. In some species there are a number of large spines on the head and the thorax known as ‘combs’ or ctenidia. There may be a genal comb on the cheek (gena) and a pronotal comb on the posterior border of the first thoracic segment (Soulsby, 1982). These combs or ctenidia belong to one of the three sets of characteristics in morphological taxonomy for identifying fleas. Thoracic and leg structures and the structure of the male segment IX, the female sternite VII and the sperm holding organ (spermatheca) are the other two characterising sets (Ménier and Beaucournu, 1998).