The spitfire sawfly (Perga affinis or Pergagrapta bella, family Pergidae) is a hymenopteraninsect found in Australia. It is up to 22 mm long. It has two pairs of wings, with a wingspan up to 40 mm. Its wings are honey colored. Its larvae are up to 80 mm long. The sawfly derives its name from the saw-like ovipositor of the female, which is used to open holes in plant within which she lays her eggs. While closely related to wasps, sawflys are somewhat under-evolved and as such lack both the refined body and stinger of the wasp. Although the adults of this sawfly species are not often seen the larvae are quite conspicuous as they grow larger, resembling hairy caterpillars. Steelblue sawfly larvae are usually seen during the day in groups on the branches and stems of Eucalyptus trees. At night they disperse to feed on the leaves of the host plant. When threatened the larvae will raise their head and spit out a yellow-green liquid. It is this action that gives them their common name of 'spitfires'. This strong smelling liquid consists predominantly of eucalyptus oil and is used as a deterrent against predators.
