The spitfire sawfly (Perga affinis) is a species of hymenopteran insect in the family Pergidae.

The sawfly derives its name from the saw-like ovipositor of the female,[1] which is used to open holes in the plant within which she lays her eggs.

When threatened, the larvae raise their heads and eject a strong-smelling, yellow-green liquid consisting predominantly of eucalyptus oil, to deter predators.

Pupation takes place in strong, paper-like cocoons, which are often clustered several centimetres deep in the soil.

This defoliator rarely causes widespread damage, but where the clusters of larvae are accessible, the simplest method of control is to remove and destroy them during the day.