Pasture day moth

Farm consultant, Tim Condon (Delta Agribusiness), has reported that pasture day moth caterpillars have been observed in numerous paddocks around Harden, in the south west slopes of NSW. Tim says the amount of damage has been minimal, although one paddock of forage brassica was severely damaged. A border spray with a synthetic pyrethroid was used to control caterpillar numbers in this paddock and was reported to achieve excellent control. Tim says that he has not previously seen such high pasture day moth populations around Harden. 

Pasture day moth (Apina callisto) caterpillars are easily identified when they are fully grown (about 50-60 mm long) by their dark brown to black colour and reddish-orange markings. They also have two prominent yellow spots near their rear end which become more apparent as they mature in size. When viewed closely, they are noticeably hairy, with prominent bristles. Tim says the caterpillars he has observed around Harden are about 30-50 mm in length, and were seen in numbers of about 5-10 per square metre.

Adult pasture day moths are brown with yellow markings on the wings and orange rings on the body. They fly in autumn and, as the name implies, are active during the day. Eggs are laid in pasture and hatch at the onset of rains. When the larvae are fully grown they may be seen burrowing in the soil before becoming pupae.

It is important to correctly identify caterpillars, as an assortment of species may be present including brown pasture looper and pasture web worm. Pasture day moth caterpillars will preferentially feed on broad-leaved weeds and often leave cereals and grasses untouched where they have a choice. For further information on pasture day moths, refer to PestFacts Issue No. 7.