Insect pest risk
|High risk||Moderate risk||Low risk|
||Pre-sowing check of paddocks|
||Use of non-selective pesticides for other pests in vegetative stages can flare helicoverpa.||Maize varieties with husks extending 50-80 mm beyond the top of the cob and closing tightly around the silks restrict entry of larvae into the cob.|
|Black field earwig||Damaging|
|Swarming leaf beetles||Damaging||Damaging|
|Red shouldered leaf beetles||Present||Damaging||Present|
|Green vegetable bugs||Present||Damaging||Damaging|
|Two spotted mites||Present||Damaging|
|Red banded shield bug||Present||Damaging||Damaging|
|Yellow peach moth||Damaging|
|Present||Present in crop but generally not damaging
|Damaging||Crop susceptible to damage and loss|
Key IPM considerations for maize
- Economic damage is most likely to occur during establishment. Use germinating grain baits or direct soil sampling to provide information on risk.
- Use hybrids with resistance to wallaby ear (a mycoplasma transmitted by maize leafhoppers)
- Where helicoverpa larvae are present after mid March, the majority will enter diapause when they pupate. Pupae busting to prevent population carryover makes a valuable contribution to the area-wide management of H. armigera in the local area.
- The use of NPV for helicoverpa control in maize is effective, and can be applied through overhead irrigation (centre pivot/lateral move).