From Timothy Twongo and Geoffrey Howard
Fred Pearce meant well when he wrote about the water-hyacinth infestation on
lake Victoria and the efforts to control it, but we think he missed the real
scoop by ignoring the fact that biological control is now beginning to work
(“All-out war on the alien invader”, 23 May, p 34
and Letters, 20 June, p 55).
Two species of Neochetina weevils were introduced into Lake Kyoga in
Uganda in 1993 and into Lake Victoria, which straddles Uganda, Kenya and
Tanzania, in the past few years. In Kyoga the insects have virtually eliminated
the mobile component of the weed and are well established in Victoria, although
in some places they have not yet spread far from their release sites.
We believe that the only sustainable form of control will be biological
control and that the chemical approach is neither sustainable nor safe for the
other occupants of Lake Victoria.
Jinja, Uganda , Nairobi, Kenya
