Bushland another tool for insect pest management

New research indicates that growers could benefit from 'looking beyond the paddock’ for insect pest management, and that remnant native vegetation may be another tool for the control of insect pests in grain crops.

The findings are from a nationally coordinated project supported by the Grains Research and Development Corporation (GRDC) which aims to understand which landscape features contribute to the control of pest populations in crops.
 
Led nationally by CSIRO, the project has involved field work in Western Australia’s Great Southern region, Dalby in Queensland and Cootamundra in New South Wales.

In WA, field research has been conducted by the Department of Agriculture and Food (DAFWA) and led by DAFWA researcher Svetlana Micic.

Ms Micic said that data taken from remnant vegetation in WA showed that insect pests were more likely to be found on weeds, while beneficial species were more likely to be found on native plant species.

"Remnant bushland containing few weeds may reduce the number of pest species and at least delay the build-up of pests in crops during the growing season,” she said.

"In our studies, weeds likely to host pests included nightshade, capeweed, fleabane, mustard, wild radish and weed grasses.”

CSIRO researcher Hazel Parry, who analysed the WA data, said beneficial insects were three times more likely than pest species to be found in remnant native vegetation.

She is now using computer simulations of landscapes to understand which management practices – within crops and pastures as well as native vegetation – affect pest populations by encouraging beneficial insects or reducing sources of pests.

"This information may be useful for growers thinking about revegetation options on their land,” Dr Parry said.

"Initial results from WA suggest that native vegetation - that is well managed, is not over-grazed and has an intact under and middle plant storey - has less weeds and harbours fewer pests.”