Eradication Of Mosquitoes
p. 71 · Read in the full issue
AN outstanding instance of mosquito eradication is the elimination of Anopheles gambiae Giles from Brazil.
This species was found in Brazil in 1930 and serious outbreaks of malaria occurred in a small area that year and in 1931. It did not attract attention again until 1938 when it caused the deaths of about 20,000 persons in the 12,000 square miles it then occupied.
The Brazilian Ministry of Health, co operating with the Rockfeller Foundation, concluded a successful eradication pro gramme by the end of 1940.
Apparently a very successful campaign is also being waged in Brazil for the complete eradication of the yellow-fever mosquito, Aedes aegypti (L.). An inten sive programme has been under way for several years and many large areas now seem to be free of this species.
In 1943 Anopheles gambiae was re ported to have caused more than 130,000 deaths in Egypt, having extended its area from the Sudan along the Nile to within 200 miles of Cairo. The Egyptian Government, co-operating with the Rock feller Foundation, assigned more than 4,000 personnel to the task of eradicating this species, which was reported accom plished by the end of 1945.
In Southern Rhodesia the tsetse fly.
Glossina morsitans Westw., has been eradicated from more than 6,000 square miles during the past 10 years, following a programme based on the destruction of all big game in fenced belts 10 miles in depth and 100 or more miles wide. A different method has been successful on the Gold Coast in West Africa against Glossina palpalis RD, and G. tachinoides Westw. From 1940 to 1945 more than 1,000 square miles in an area of very heavy incidence of sleeping sickness were freed of these flies by clearing stream banks of certain vegetation.
In Zululand in the Union of South Africa, where Glossina Pallidipes Aust. is the predominant species, a large-scale experiment in eradication is now being conducted on 40 square miles of bush country, applying a DDT solution by air plane. A recent letter from Dr. Rene du Toit, Veterinary Officer, gives some very interesting details. As to results, he says; “In the Mkuzi Reserve five applications spaced at two-weekly intervals have to date resulted in the almost entire elimi nation of the tsetse flies in the area . . .
So far as other species of insects are concerned the effect upon Anopheles gambiae has been profound. This is a notorious malaria area and not a single case of malaria has developed in a per sonnel of approximately 50 camped in the area throughout the summer months/’
Thus it would seem that in any area in which tsetse flies are eradicated by chemical means, malaria might also dis appear.—From “Tropical Agriculture.”