Caterpillars with a characteristic looping motion that chew seedling broadleaf crops. They are most damaging in autumn when large caterpillars (>20mm) transfer from summer and autumn weeds onto newly emerged canola seedlings.
What to look for
Paddock
Canola seedlings with caterpillars chewing leaves.
Damage is frequently worse near fence lines adjacent to pasture paddocks or rock heaps.
Plant
Plants have leaves chewed from the edges, and the caterpillars are often present.
Insect Larvae
Slender grey or brown caterpillars with black and cream stripes.
Young caterpillars move with a characteristic looping motion. When the caterpillars reach full size at 30mm long, they cease to move this way.
Insect Adult
Moths are up to 20mm long and pale dusty brown with grey and brown streaks on the forewings. when at rest the wings are folded over the body.
Where did it come from?
Eggs are laid in early to mid autumn.
The caterpillars that hatch from the eggs grow to full size in about two months, then pupate and remain in the pupal stage over spring and summer.
They emerge as moths in the following season.
Brown pasture loopers have only one generation per year.
Management strategies
Spraying insecticide
Brown pasture loopers are easily controlled by insecticides.
How can it be monitored?
Check crops from emergence, especially the edge of crops adjacent to pasture or crops seeded into paddocks with a green bridge.
