Brown pasture looper

Brown pasture loopers (Ciampa arietaria) have been identified for consultant, Sandy Biddulph (Biddulph Rural Consulting), damaging lucerne in two paddocks north west of Cootamundra, in the South West Slopes district of New South Wales. The lucerne has been grazed and Sandy says the loopers are defoliating plants and holding back re-growth. In the worst affected areas 10-20 larvae could be found per lucerne crown. The affected paddocks had some shepherd’s purse and other broadleaf weeds present, which may be the initial source of this pest.

Brown pasture loopers attack canola and lupin crops, as well as pastures and broadleaved weeds. They have just one generation per year. Adult moths lay eggs from March to June, after which the caterpillars hatch and are active for approximately 2 months. They are generally present from July to October and can cause early season defoliation of plants when numbers are high. They are most damaging when large sized caterpillars (>20 mm) transfer from summer and autumn weeds onto newly emerged seedlings.

Brown pasture loopers are often prevalent around patches of weeds, particularly capeweed, and around the edges of crops. These areas should be monitored closely and spot or perimeter spraying is often all that is required. Chlorpyrifos and bifenthrin are registered for the control of brown pasture loopers in lucerne.

Larvae of the brown pasture looper vary in size, growing to 20–35 mm in length. They move using a series of back arches, which results in a characteristic looping motion. Larvae are dark brown to grey in colour with a yellow line along the back either side of a conspicuous dark band. They have red spots surrounding the breathing holes (spiracles) on the sides of the body. Moths are pale dusty brown in colour with grey and brown streaks on the forewings.

Click here for images of the brown pasture looper.