Philomastix xanthophilax

Philomastix xanthophylax Naumann & Groth, 1998
Red-Ash or Bramble Sawfly
PERGIDAE, SYMPHYTA, HYMENOPTERA

Don Herbison-Evans
(donherbisonevans@yahoo.com )
and
Stella Crossley

Philomastix xanthophilax
(Photo: courtesy of Harold McQueen, Brisbane, Queensland)

These are not true Caterpillars, but are the larvae of a Sawfly (which is really a wasp, or more accurately a Symphytan). These larvae are green, with a pale brown head, a yellow stripe along each side, and two tail filaments. This species feeds on :

Red Ash ( Alphitonia excelsor, RHAMNACEAE ).

(Photo: courtesy of Harold McQueen, Brisbane, Queensland)

To pupate: the larvae burrow into several centimetres into the ground near the base of their food tree. The pupae are very dark brown and rounded.

An female adult insect (it is misnamed as a 'fly') is brown with a yellow tip to the abdomen.

female
(Photo: courtesy of Peter Chew, Brisbane, Queensland)

The females lay their eggs on the undersides of foodplant leaves while sitting on the top of a leaf, by creating a hole in the leaf, and poking their abdominal ovipositor through the hole to the other side. The females have misshaped wings and cannot fly, but stay by their eggs, apparently guarding them.

The males are smaller, and can fly,

The species has been found in

Queensland, and

New South Wales.

Other Sawfly species have different foodplants.

Further reading :

Ian D. Naumann & H. (Mike) Groth,
A Revision of the Philomastigine Sawflies of the World (Hymenoptera: Pergidae),
Journal of Hymenoptera Research,
Volume 7 (1998), p. 142.