Paper wasp peak season

Southern brown paper wasps, Mount Cotton.

Walking through Sandy Creek Conservation Area last weekend, I was pleased to find that quite a number of paper wasp colonies had formed along the barbed-wire perimeter fence.

Most frequent were the misshapen hanging nests of the southern brown paper wasp (Ropalidia plebeiana), a medium-sized species with a few pale bands around its body.

Common paper wasp, Mount Cotton.

Also seen, however, were common paper wasps (Polistes humilis), a slightly larger, more colourful species that makes an upside-down mushroom-shaped nest.

Wasp colonies are at their largest during autumn, and these at Mount Cotton are likely to be producing males and fertile queens in the near future.

The majority of the colony perishes during the cooler winter months, but the queens that hatch in the autumn will hide in crevices or under tree bark to await spring, when they will start the colony anew.

Most of the wasps in each colony are infertile worker females, who help construct the nest and capture prey for the larvae inside each chamber.

Like many scientists and naturalists, I am fascinated by the social behaviour of these creatures; the latin name for many of them refers to this aspect of their nature, with names like Ropalidia socialistica, R. proleteria, R. gregaria and R. aristocratica.

On my front porch at the moment is a colony of small brown paper wasps (R. revolutionalis), whose narrow, vertical twig-like nests might be something you recognise from your property also.

I tend not to worry about the presence of these creatures, as they are harmless unless their nest is disturbed (or attacked, from their perspective) and they feed their larvae on the caterpillars that would otherwise be defoliating the garden plants.