Pruinose Scarab

Scientific Name:

Sericesthis germinata

Order:

Coleoptera

How to identify Pruinose Scarab?

The pruinose scarab larva is a white to creamy-white soft-bodied grub, up to 20mm long with 3 sets of legs and a hard light brown head capsule.

• As with most scarab pests, the larvae can be difficult to identify between species as only subtle characteristics distinguish them from other beetle larvae.

• When mature the adult beetle possesses a dark brown to black carapace up to 16mm long and has a unique set of antenna with have large club-like ends.

• The underside of the body is covered in short grey hairs.

What is the biology and lifecycle of Pruinose Scarab?

Adult Pruinose Scarab emerge from pupation under the soil in early spring, and often fly to eucalyptus trees to mate before returning to the soil to lay 20-40 eggs. The larvae then hatch and burrow into the soil where they remain for a period of 8-10 months before emergence the following spring. Larvae will mainly eat decaying organic matter though in large numbers their minor feeding activities on plant roots can cause injury. Adults then hatch in spring and live fore 1-9 weeks.

Turf damage by Pruinose Scarab typically occurs through plant injury due to larval feeding, though high pest pressure can result in disrupted surfaces of bowling greens as well.

• Plague proportions can be reached following warm, dry winters.

• Larvae feeding on root material can result in discolouration of turfgrass and eventually plant death, often in irregular patterns but over large areas in severe cases.

• Severely affected turf can be rolled back as roots are sheared off, to expose white larvae underneath the thatch layer.

To manage and control Pruinose Scarab it is important to ensure infested areas of turf have do not suffer from moisture stress as this will exacerbate the symptoms of damage cause by larvae feeding.

For chemical solutions and treatments for Pruinose Scarab, please see our recommended products below.