Mosquitoes go through four phases: (1) ovum, (2) larva, (3) nympha, (4) complete insect.
The absence or extreme paucity of mosquitoes no doubt accounts for the infrequency of malarial fever in the interior.
One noteworthy feature in Liberia, however, is the relative absence of mosquitoes, and the white ants and some other insect pests are not so troublesome here as in other parts of West Africa.
Mosquitoes are innumerable, and moths and ants of the most destructive kind, as well as others equally noxious and disagreeable.
In 1900-1901 Major Walter Reed (1851-1902), a surgeon in the United States army, proved by experiments on voluntary human subjects that the infection was spread by the Stegomyia mosquito,' and the prevention of the disease was then undertaken by Major William C. Gorgas - all patients being screened and mosquitoes practically exterminated.'