The tsetse African small biting flies have a peculiar life cycle, can have its population reduced in various ways, transmit the wormlike trypanosomes, and are the cause of the sleeping sickness disease as discovered by Dr. David Bruce, parasitologist and early treatment provider.
Tsetse flies may be subtle in appearance as they are similar to house flies. Like all insects, an adult tsetse fly has three sections: a head, thorax, and abdomen.
The head comprises two huge eyes on each side and a large bulb on the bottom to which is attached a forward-pointing proboscis, or the part through which blood is sucked. The large thorax comprises three combined segments, six legs, two wings, and two organs for balancing, called halteres.
The abdomen is small but increases in size as the fly consumes enough blood to weigh twice as much as its original weight. Most tsetse flies are extremely tough externally. It is difficult to crush one.
Tsetse flies are different in four distinct bodily characteristics: proboscis folded wings, hatchet cell, and branched arista hairs. A long proboscis protrudes forward and is connected to the bottom of the pest’s head by an obvious bulb.
The fly folds its two wings fully one above the other while resting. Hatchet cell refers to a cell in the center of both of a tsetse fly’s wings.
These distinct cells are so named because of their hatchet shape. The bristle-like parts of the creature’s antennae, called the arista, have branched hairs.
The tsetse fly has a peculiar life cycle. A female can only produce one egg at a time. The egg hatches inside the fly and the larva lives on a milky substance within the mother. The larva then leaves the mother and burrows into the ground.
Once in the ground, the larva forms a hard outer case in which it changes. During this period the larva feeds on stored food. It is now a pupa. After twenty to thirty days, the case is broken and an adult tsetse fly emerges.
Sleeping sickness, transmitted by the tsetse fly, is a parasitic disease that is found in areas south of the Sahara Desert as far as the Cape of Good Hope.
There are three strains of sleeping sickness, which affect man and beast. East African and West African are the two strains in humans while nagana in the form of the disease found in animals.
Infected with either of the two strains an individual will not seem plagued for one or two weeks. The victim will subsequently experience recurring fever, pains, and aches. The back of the neck will swell eventually.
This is a sign, called Winterbottom’s sign, which is used by doctors to determine the presence of the sickness. At a touch, the neck will pain. In the case of the East African strain, if it goes untreated there is swift death.
The West African strain, however, will cause a longer period of illness, as long as two to three years. In this period, the victim will experience several symptoms that will cause suffering. These include intense headaches, lack of concentration and interest, weariness during the daytime, and problems sleeping at night.