too bad to eat

Some grasshoppers survive by being unpalatable to predators, writes MARTYN ROBINSON

When food is marinated, it takes on the flavour of the marinade, and animals that are raised on a special diet may taste different to those fed ordinary food. Some species even consume certain foods so they don’t end up being eaten at all! A good example of this is the unfortunately named pustulated pyrgomorph grasshopper (Monistria pustulifera). The ‘pustules’ are attractively coloured raised spots, and pyrgomorph means ‘fire body’, referring to its red and orange patterns.

It’s hard for such brightly coloured grasshoppers to hide, and they are quite slow and easy to catch. Few have fully developed wings, and those that do use them to migrate rather than escape. So how do they survive? They start life as tasty green grasshoppers that can hide from predators, and their defence when they’re adults is that they taste terrible. This is broadcast by their bright colours. Their preferred food plants are from the genus Eremophila (emu bush, native fuchsia, poverty bush), which contain chemicals in the leaves to make them taste nasty. The chemicals are incorporated into the grasshopper’s body.

When they are young, pyrgomorphs hide low on the stems of eremophilas and swivel to the opposite side as predators approach, then as they grow and their pattern appears, they move higher up to flaunt their ‘untastiness’.

Most of the pyrgomorph grasshopper species eat unpalatable plants to make themselves inedible. Mint bushes (Prostanthera spp.) have their own species, with spotted bodies, that feed on them. The common pyrgomorph (Monistria discrepans) is found around mint bushes in eastern Australia.

It makes you wonder why we eat so many spicy foods that other animals avoid, doesn’t it? Garlic, chilli, chicory, mustard and similar foods might be a throwback from us trying to make ourselves inedible!

Martyn gardens mainly on Sydney’s Northern Beaches