7 October 1999

Dead Bugs To The Rescue

by Kate Melville

Enzymes produced by insects could be sprayed onto crops or fruits to clean up residues of chemical pesticides, say researchers.

In an interesting colonial exchange program Professor Alan Devonshire from the UK, joined CSIRO Entomology researchers for twelve months to help them study bioremediation, the cleaning up of environmental contamination by biological means. Professor Devonshire hails from Rothamsted, the oldest British agricultural research establishment, and he is also Special Professor in the Department of Genetics at the University of Nottingham.

According to Professor Devonshire, "Insects develop the ability to break down poisons and become resistant to them. We can use this insect ability to break down unwanted toxic contaminants in the environment." Everyone who has experienced serious insect pest problems understands about insecticide resistance. Our work has shown that resistant insects have developed the ability to break down the harmful chemicals in insecticide sprays, and we have isolated the enzymes, which the insects produce. If we can produce larger quantities of these enzymes in a form which can be sprayed or applied in the field, residues of the harmful chemicals can also be broken down."

The aim of Professor Devonshire's pesticide bioremediation project is to develop techniques for the detoxification of pesticides in irrigation run-off, and chemical pesticides remaining on the surfaces of commercial commodities.

The CSIRO research group is a world leader on insecticide resistance mechanisms," says Dr Jim Cullen, Chief of CSIRO Entomology. "We are seeking closer collaborative ties between CSIRO and Rothamsted, and pesticide biochemistry is an area of broad and ongoing mutual interest both with CSIRO and with other Australian agricultural research institutions. We have been focusing our research on the isolation of the specific enzymes, which break down the organophosphates, which have been used for years as insecticides. We are particularly interested in finding environmentally-friendly ways of clearing irrigation channels of residues, and of being able to clean residues off fruit, prior to exporting or marketing the produce".