In a move that could save the environment, village economies and even human lives, CSIRO scientists have wiped out 20 square kilometres of a noxious water weed infesting the Sepik River in PNG.

Researchers from CSIRO Entomology used tiny weevils as biological control agents to control a massive outbreak of the exotic Latin American weed, water hyacinth, that was threatening the river, the villages which depend on it and the natural environment of PNG.

The project, funded by AusAID, is a fresh triumph for Australia's "six-legged ambassadors" - tiny benign insects now saving crops, family livelihoods, industries and ecosystems around the Asia Pacific region.

Water hyacinth infestations clogging up the Sepik River wetlands were causing great hardship to people using the rivers and streams to move around the country - like a road network.

According to Mr Mic Julien from CSIRO Entomology, the release of biological control agents such as weevils dramatically reduced the areas covered by the weed.

"Over the past five years, we have released 450,000 weevils and reduced infestations from 27 square kilometres to just seven," Mr Julien says.

The Sepik River system is a major waterway in PNG. Water hyacinth was first recorded in the Lower Sepik River floodplain in 1984 and spread quickly, infesting many lagoons and hundreds of kilometres of river banks.

By 1991, large water hyacinth infestations were severely disrupting the lifestyle of villagers from the Middle and Lower Sepik who could only reach gardens, markets and fishing by using the waterways.

These infestations also resulted in the deaths of several people who were unable to reach essential services in time for life-saving treatments.

The government of PNG realised that it was neither desirable or practical to control the weed with herbicides and so alternative control methods were so
'"/>

Contact: Mic Julien
mic.julien@ento.csiro.au
61-7-3214-2805
CSIRO Australia
14-Jul-1998