Week Five: Oriental Rat Flea

Common Name: Oriental Rat Flea

Scientific Name: Xenopsylla cheopis

Not-So-Fun Fact: Oriental rat fleas are the primary host of the bacterium Yersinia pestis, which when introduced into the human bloodstream causes bubonic plague. At dozens of instances in human history, the fleas have bitten and infected individual humans and in turn created massive epidemics of the plague in Asia, Africa, and Europe.

Domain: Eukaryota

Kingdom: Animalia

Phylum: Arthropoda

Class: Insecta

Order: Siphonaptera

Family: Pulicidae

Genus: Xenopsylla

Species: X. cheopis

Description: Oriental rat fleas have flattened, bulbous bodies and long, powerful, hairy legs. They are the usual semi-translucent brown color common among fleas. Their mouthparts are specifically adapted for the ingestion of blood, and are very complex. Their digestive tracts are easily blocked by bacterial masses.

Environment: Both this species of flea and its deadly parasite originated in central Asia, specifically in Mongolia and China. The flea is now found wherever its primary host, the rat, can be found. Other, less preferable hosts include cats, dogs, chickens, and humans.

Reproduction & Development: Like many more benign insects, Oriental rat fleas go through four main life cycle stages. After two to twelve days, the egg hatches into a larval form. The larva will go through three molts before spinning a cocoon and becoming a pupa. The flea then emerges as an adult. Any one of the temporary stages may be prolonged by environmental factors, and indeed the speed of pupal development is entirely dependent upon its surroundings.

Nutrition: The flea survives off of the blood of its host, which is sucked through its sharp proboscis. This process is sometimes hindered by the large quantities of plague bacteria which can block the gut of the flea and eventually starve it to death after a period in which the flea bites as many host animals as possible in its desperate quest to properly slake its thirst for blood.