Water hyacinth, Eichhornia crassipes
of water hyacinth in many countries around the world is a spectacular
example of successful biocontrol. Water hyacinth, a native of the
upper Amazon catchment, is one of the world's worst aquatic weeds
and was probably imported as an aquarium plant. It is first recorded
in Australia in the 1890s. Once in rivers, dams and lakes, it can
double its size within a few weeks, forming mats which impede the
use and ecology of the waterways.
agents were released in Australia in the 1970s and 1980s, building
on the initial research done in the USA. The tunnelling larvae of
these insects achieved good control in impoundments in sub tropical
and tropical eastern Australia.
But it is overseas
where CSIRO's expertise has had the most spectacular results. Most
control has been achieved by two weevils, Neochetina bruchi and
N. eichhorniae. Massive infestations in the Sepik River lagoons
(Papua New Guinea), were cleared in less than five years. Similarly,
in collaboration with a range of organisations, huge infestations
in Lake Victoria (Kenya, Uganda and Tanzania) were cleared of water
hyacinth in less than three years. The technology has also been
used by others with dramatic effects in Benin (West Africa), South
Africa and Thailand.
by: Australian Centre for International Agricultural Research