(Photo: courtesy of Tim Ellis, taken in Melbourne, Victoria)
Sawfly larvae are not true Caterpillars, but are the larvae of various species of wasps, or more accurately Symphyta. They have 3 pairs of true legs, and up to 8 pairs of prolegs (true caterpillars only have up to 5 pairs of prolegs).
There are about 200 known species of Sawfly in Australia.
The larvae of some Sawfly species are green, some black, others brown or off-white, and some are striped, and some are spotted. Some are smooth and some have bristles.
Some have brown heads, others black.
Some have blunt tails, some pointed. Some have white tails, some black, and some have forked tails.
Different species feed on plants from different families. Different species vary in size, some growing to a length of about 5 cms.
The larvae of some species are solitary. The larvae of other sawfly species are so gregarious that they are often found in a knotted ball of many individuals.
They characteristically respond to a perceived threat by raising their tails in the air.
When disturbed, they curl or wriggle their tails and exude a nasty brown fluid from their mouths. This latter habit has given them the common name of "Spitfires", although they do not actually spit the fluid, just dribble it.
They sometimes use the tapping of their tails to communicate with each other.
Some Sawfly larvae pupate in a cocoon, and some pupate naked, Typically they pupate in the leaf litter, and the pupal duration can be up to two years.
An adult wasps, or more accurately Symphytans, of different species vary in wingspan from 1 cm. to 4 cms. Different species have various colour schemes, including black, white, brown, and orange, and some have the odd coloured spot and/or abdominal bands.
The female of many species lays her eggs in a slit she cuts between the upper and lower skins a leaf of a food plant: an amazing feat of dexterity.
The larvae and adults of this family are quite harmless to people. They do not sting, unlike their cousins the communal wasps. Sawflies are found all over the world, for example :
Common species of Sawfly larvae in Australia include:
Further reading :
Reed International Books Australia, Port Melbourne, 1999, pp. 5, 10-11.
(updated 29 October 2012, 4 April 2018, 13 August 2020, 13 February 2021)