Pasture day moth

Agronomist, Phil Bowden (NSW DPI), has reported pasture day moth (Apina Callisto) causing damage to several pasture paddocks around Cootamundra and Junee, in the South West Slopes district of New South Wales. Some canola paddocks have also experienced feeding damage. Pasture day moths were a major problem at this time last year across much of southern New South Wales, mostly attacking cereal and emerging pasture crops. It is advisable to keep a look out for this pest in these areas.

Pasture day moth caterpillars are easily identified when they are fully grown by their dark brown to black colour and reddish-orange markings. They grow to about 50-60 mm long and 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. Click here for images of pasture day moth caterpillars.

The adult moths are brown with yellow markings on the wings and orange 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. The pasture day moth passes through only one generation per year and is found in most southern areas of Australia, ranging from lower Queensland to Tasmania.

Pasture day moth caterpillars have a preference to feed on broadleaved weeds and will often leave cereals and grasses untouched where they have a choice in pastures. However, in paddocks where caterpillars are present and broad-leafed weeds are dead or dying from a previous herbicide spray, the grubs will transfer off the dying host plants and onto nearby plants.

Phil reports that many crops are now growing away from the pest pressure. However, if crops are stressed they could still experience significant damage and control may be warranted. Alpha-cypermethrin is reported to provide good control of pasture day moth caterpillars.