13 October 1995

Lethal look at grain pests

PNEUMATIC conveyors are more lethal to grain pests than elevators and augers, says the Central Science Laboratory in a new Home-Grown-Cereals Authority report.

Studies comparing different methods of shifting insect-infested samples found that only a pneumatic approach killed large numbers of the three pests assessed, the rust red flour beetle, the grain weevil and the saw-toothed grain beetle.

Boost weevil numbers

Both auger and elevator seemed to boost weevil numbers, probably by shaking them out of the grains during conveying, says the CSLs David Armitage.

Survivors did not seem to vary in their susceptibility to insecticides.

Further work with pneumatics could reduce the need for pre-export use of pesticides, says Mr Armitage. "Unfortunately, most export terminals use belt conveyors."