Tsetse Flies Are Strange and Dangerous Insects

By Kevin Fitzgerald @ Entomology Today


Tsetse flies are the scourge of Central Africa. The flies are vectors for the disease nagana, also known as African animal trypanosomiasis (AAT), in wild and domestic animals, and a similar disease among humans that is known as sleeping sickness, or human African trypanosomiasis (HAT). The agents of the diseases are trypanosomes, protozoa that live within the tsetse fly. Parts of Africa are uninhabitable because of the presence of tsetse flies and their effects on people and livestock.

There are about 34 species and subspecies of tsetse, depending on classification schemes, all in a single genus, Glossina. These flies suck blood for food from the muscle tissue of animals and people, picking up pathogens from an infected host or injecting pathogens they carry into a host. A tsetse can suck up its weight in blood.

Tsetse flies have developed an array of hard-to-believe adaptations. For example, they suckle their young in a uterus, and they give birth to live young. The phenomenon is called adenotrophic viviparity, or “gland fed, live birth.” The vast majority of insects do not show this behavior, but it is the preferred mode for all of the species in Hippoboscoidea, the superfamily to which tsetse flies belong.

A female tsetse mates once in her lifetime, on or near a target species, but she’s pregnant for her entire life, which lasts about four months. Males initiate mating when they sense a pheromone on the female’s body. The mating lasts for up to two hours. Tseste flies have two ovaries and each holds two ovarioles where eggs are developed. Sperm from the male are stored in a structure called a spermatheca in the female and kept alive there......To Read More....and it gets far more interesting.