Bacillus thuringiensis var. israelensis H-14
(Bti) is a spore-forming bacterium that produces a toxin lethal
to mosquito larvae. It has been shown to be safe for both people
and the environment. Although Bti is produced commercially, it is
very expensive to import. However, Bti can be produced locally using
coconuts.
In
many tropical areas, coconuts are both cheap and abundant. The fruit
is a natural incubator for culturing Bti, which is then applied
to ponds where malaria-transmitting mosquitoes breed. The mosquito
larvae eat the bacteria along with algae and are killed. The toxic
strain of Bti fermented in coconuts, when applied to ponds and other
breeding sites, kills virtually all the mosquito larvae and stops
further larvae development for up to 45 days.
In
the village of Salitral on Peru's semi-tropical northern coast,
coconuts are plentiful. Dr. Ventosilla and her team have been teaching
local people a simple way to combat malaria. Youth and adults participate,
bringing along their own knives and candle wax to the training sessions.
Villagers are taught how to correctly douse cotton swabs in Bti.
The swabs are then inserted into each coconut through a hole cut
in the top and sealed with wax. After the coconuts have fermented
for two-to-three days, depending on their size and the local temperature,
the villagers take them to a nearby pond, break open the fruit,
and toss it into the water. A typical pond requires two or three
coconuts for one treatment. |
