Ten to 20 mature larvae can kill an average rosette. Trials at Yanco near Leeton in New South Wales show the insects multiply quickly, jumping from 60,000 to 150,000 in one year. Paterson's curse crown weevils have been given out to farmers around the country. Some are happy about the insects. Others are sceptical.
Scientists say farmers can relax.
The bugs are safe. The literature tells us that insect 'X' will have a certain range. We then go and collect insect 'X' and bring it back to Australia in quarantine. We then spend two years exposing it to a range of native and agricultural species to see if it'll indeed switch hosts and attack them only. If the insect doesn't do that we release it into the country.