In the past, it's been easy to control them with chemicals. But it's now known that some chemicals can cause even more problems than they solve.

When tonnes of grain are stored in huge silos like these, it's difficult to keep out the grain-loving pests. One efficient cure has been methyl bromide, but like chlorofluorcarbons, or CFCs, it also depletes the Earth's vital ozone layer, increasing the harmful ultraviolet radiation reaching the earth, which has been blamed for an increase in skin cancer.

For many years CSIRO scientists have been working on several different ways to kill off the pests without damaging humans or the environment.

The industry now has moved away from the use of insecticides to the use of gases. These are carefully contained, used at very low level, they're using increasing quantities of cooling and they're generally decreasing the use of toxic chemicals and moving to non-toxic techniques.

For example CSIRO has pioneered several improvements in the use of the gas phosphine as a grain fumigant. Phosphine is effective and will not harm the ozone layer.

Scientists at CSIRO are continuing to develop new ways to protect Australia's grain, the environment, and Australia's position as one of the world's leading grain export countries.