Tunga penetrans

Jigger flea
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Siphonaptera
Family:	Hectopsyllidae
Genus:	Tunga
Species:	T. penetrans
Binomial name
Tunga penetrans (Linnaeus, 1758)

Tunga penetrans (chigoe flea or jigger) is a parasitic insect found in most tropical and sub-tropical climates. It is native to Central and South America, and has been inadvertently introduced by humans to sub-Saharan Africa.

Synonyms for Tunga penetrans include Sarcopsylla penetrans, Pulex penetrates, and many others. In its parasitic phase it has significant impact on its host, which include humans and certain other mammalian species. A parasitical infestation of T. penetrans is called tungiasis.

T. penetrans is the smallest known flea, at only 1 mm. It is most recognizable in its parasite phase. While embedded under the stratum corneum layer of the skin, it may reach up to 1 cm across. During the first day or two of infestation, the host may feel an itching or irritation which then passes as the area around the flea calluses and becomes insensitive. As the flea's abdomen swells with eggs later in the cycle, the pressure from the swelling may press neighbouring nerves or blood vessels. Depending on the exact site, this can cause sensations ranging from mild irritation to serious discomfort.

[credits: Gordon, 1941; Bruce et al, 1942; Grosshans and Pradinaud, 1979; Macias and Sashida, 2000; Muehlen et al, 2003; Sachse et al, 2007]

The colloquial name jigger may be confused with chigger, a parasitical mite. However, the jigger is of the order Siphonaptera as it is a flea. The chigger is a minute Arachnid. Mites penetrate the skin and feed on skin cells that are broken down through an enzyme they secrete from their mouthparts, but they will then leave the host. The adult and the larval forms both feed on other animals. This is not the case with T. penetrans, as only the adults feed on mammals, and the mature female remains in the host for the rest of her life.

...
Wikipedia