Agronomist, Dave Elworthy (McAlister & Saunderson), reports low numbers of pasture day moth caterpillars in a pasture-lucerne paddock near Gundagai, in the south-east of NSW. Dave says the caterpillars are not causing significant feeding damage and many caterpillars can be seen burrowing in the soil.
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.
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.
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 broadleaved 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.