sustainability through science & innovation

Woollybear caterpillars

Consultant, Glenn Sheppard (IMAG Consulting), reported seeing large hairy grubs in a wheat paddock in the Collie-Warren area, in the central west slopes and plains district of NSW. Although, Glen says the grubs did not appear to be damaging the crop, he was concerned due to the high numbers observed, particularly along the edges of the paddock.

The grubs were identified by Senior Technical Officer, Ken Henry (SARDI), as woollybear caterpillars. This name refers to a specific species of the tiger moth family (Arctiidae) but is also more widely used to describe the complex of very hairy caterpillars covered with tight uniform masses of brownish–dark coloured bristles that give a woolly or fury appearance.

The adults are known as tiger moths because they mostly have bright warning colour patterns, which are striped and spotted in red, orange, black or white. They are mostly small to medium in size with a stout abdomen usually striped with black and yellow-red colour. Some are either distasteful to predators or mimic distasteful species and may produce a foul chemical.

The caterpillars generally grow to about 50mm long and have a dark coloured body with brown bristles. When disturbed, they usually roll into a tight spiral ball with the head in the centre. Very little is known about these species, although they are reported to feed during the day. They are generally not regarded as an important pest, mainly feeding on weeds.

Reports from WA indicate that when in high numbers woollybear caterpillars can cause severe defoliation and skeletonisation of a wide range of host plants and weeds. They are frequently found in home gardens as well. Glenn says birds in the area can be seen in high numbers feeding on the grubs. Control measures where not implemented as there was no observable feeding damage to the crop.

PestFacts is supported by