Grass anthelid

Very high numbers of grass anthelid caterpillars (Pterolocera spp.) have recently been found in several pasture paddocks around Ballarat, in the Western district of Victoria. Agronomist, Chris Bluett (VIC DPI), reports finding at least one instance where the caterpillars had formed a frontal band and were moving across the pasture leaving it completely bare behind them. Occurrences appear to be very localised and most sightings have been on small acreages or hobby farms. Chris also recalls seeing significant moth activity in the region in autumn this year, which appears to have lead to the ‘plague proportions’ of caterpillars now being found.

A closely related species of Pterolocera have also been identified for Patrick Francis, (Editor, Australian Farm Journal), from a pasture paddock near Ararat in the Western district of Victoria. Patrick reports finding approximately 20 caterpillars per square metre, feeding mostly on onion grass within the paddock. These reports follow those received earlier this season of grass anthelids moving out of grassland and damaging cereal crops in the Victorian Mallee district and on the Eyre Peninsula in South Australia.

Grass anthelids are a relatively minor pest of pastures and cereal crops, and species within the Pterolocera genus are apparently all without names. It appears that conditions in the Ballarat area have been favourable for the survival of all life stages, which has enabled numbers to build up to what is currently being found. Grass anthelids have an annual life cycle, with larvae active in late winter and spring. Larvae are covered in tufts of stout hairs and can grow up to 50 mm in length. The species encountered around Ballarat has a tawn coloured body with distinct yellow markings, whereas those found at Ararat were black with brown-orange bands and prominent white spots. Male adult moths are buff with brown markings, and have very large antennae, and adult females are flightless.

We would also like to extend a special thanks to Peter Marriott for providing assistance and advice on the identification of caterpillars in the Pterolocera group.