General Aspects

Fleas represent one of the most important external parasites. At the moment there are more than 2000 described species and subspecies throughout the world (Borror et al., 1981).

Fleas are wingless insects with a laterally compressed body of about 1.5-4 mm length. Like all insects they possess six legs and three body segments. Taxonomically they belong to the order Siphonaptera (Tenter and Schnieder, 2006) (Table 1). This family contains several species and subspecies.

Fleas represent one of the most important ectoparasites (Mehlhorn, 2000; Mehlhorn et al., 2001).

These species belong to the family Pulicidae, including Pulex spp., Ctenocephalides spp., Spilopsyllus spp. and Archaeopsyllus spp., or the family Ceratophyllidae with the genera Ceratophyllus or Nosopsyllus to mention only some of the most important veterinary and human representatives.

Fleas have a history of about 60 million years and have been found on prehistoric mammals. While becoming parasitic, the original exterior of the two-wing insects, also designated as the order Diptera, has changed by losing the wings in the adults, whereas the larval form still has similarity with the larva of the order Diptera (Strenger, 1973). About 95% of the ~2000 different flea species parasitise on mammals, 5% live on birds.

Table 1. Taxonomy of fleas
















Ctenocephalides, Pulex,
Spilopsyllus, Archaeopsyllus


Ceratophyllus, Nosopsyllus etc.


C. felis (Bouché 1835)
C. canis (Curtis 1826)
P. irritans (Linné 1758)
S. cuniculi (Dale 1878)
A. erinacei (Bouncé 1835)


C. gallinae (Schrank 1804)
C. columbae (Stephens 1829)

Further information

  • Borror DJ, DeLong DW, Triplehorn CA (eds.): Order Siphonaptera. In: An introduction to the study of insects. 5th edn., 1981, WB Saunders Co., Philadelphia, pp 620-8
  • Mehlhorn H: Mode of action of imidacloprid and comparison with other insecticides (i.e. fipronil and selamectin) during in vivo and in vitro experiments. Suppl Comp Cont Educ Pract Vet. 2000, 22 (4A), 4-8
  • Mehlhorn H, Hansen O, Mencke N: Comparative study on the effects of three insecticides (fipronil, imidacloprid, selamectin) on the developmental stages of the cat flea (Ctenocephalides felis Bouché 1835): a light and electron microscopic analysis of in vivo and in vitro experiments. Parasitol Res. 2001, 87, 198-207
  • Strenger A: [About the nutritional physiology of the larva of Ctenocephalides felis felis.] B Zool Jahrb Syst Bd. 1973, 100, 64-80 [in German]
  • Tenter A, Schnieder T: [Pathogens of parasitic diseases: Taxonomy, systematics and general criteria.] In: Schnieder T (ed.): Veterinärmedizinische Parasitologie. 6th edn., 2006, Parey in MVS, Stuttgart,  pp 26-73 [in German]

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