My first sawfly

 

Guest Post by Geoff Leslie, Warragul

Most people are familiar with the larvae of the sawfly known as ‘spitfires’. These caterpillar-like creatures are found in writhing masses on eucalypts, usually exuding green excrement and waving their heads after defoliating whole branches.  Not very attractive.

But there are many types of sawfly (Brisbane Insects has an informative sawfly page - Ed). Spitfires are the larvae of the Spitfire Sawfly, Perga affinis, apparently but I have never been able to photograph an adult.  Another well-known type of sawfly larva is the cherry slug – a black leech-shaped slimy little critter that skeletonises the leaves of pear and cherry trees. This one is Caliroa Cerasi, an introduced pest that has followed the cultivated fruit trade around the world.

Yesterday, however, I found a cooperative sawfly who consented to being photographed. It lacks a common name, though some people call it the Dock Sawfly. It is Lophyrotoma analis.

The larvae look much like spitfires but are green and usually solitary, and the host plant is usually dock weed or some other broad-leaved softer plant not eucalyptus. I found it on a broad bean.

This is a female sawfly, the males of this species have antennae with large filaments making them look like feathers.  Females have a saw-like ovipositor (egg-laying tube) with which they cut a space in the middle of a leaf – between the top and bottom face of the leaf – to lay their eggs, though my picture does not reveal this. That is obviously the origin of the name ‘sawfly’; in fact they are a primitive type of harmless wasp.

I have a lot of dock weed (Rumex species) so I welcome this beautiful little creature. Help yourself to my dock.

Thanks for the contribution Geoff - Ed