Prickly pear: the caterpillar that saved Outback Australia

Bottle trees and prickly pear mark the Australian outback with a distinctive stamp. Add to that red dirt, huge skies and seemingly endless plains and you begin to have a picture.

In the days of early settlement, prickly pear covered huge areas of inland New South Wales and Queensland. The cactus plant was introduced from South America to establish a cochineal dye industry, using the scale insect that lives on the pear. By the 1920s, 26,000,000 ha were severely infested, with station homesteads and farmhouses literally walled in by the plant. Many properties became an impenetrable jungle. Families were forced to abandon their properties and homes. The situation seemed hopeless.

In 1925, an enterprising entomologist went to Argentina and collected 3000 eggs from the tiny cactoblastis moth. After breeding up the numbers, he distributed eggs to landholders throughout the areas infested with this noxious cactus weed. In the space of only a few years, the orange-striped caterpillars ate their way through most of the fleshy cactus. By 1933, eighty per cent of the pear in Queensland had been destroyed by the caterpillars. To the present day, this miracle insect continues its good work on any rogue cactus, never touching any other plant.

What an incredible story. Huge areas of New South Wales and Queensland were saved by an introduced insect. This is biological control at its very best.

PS

The photos show prickly pear trees which are larger than the prickly pear plant that caused so much trouble.

You have to cross a bridge to get to Roma

Our closest service town is Roma, a journey by car of about one hour in an easterly direction, towards the coast -- and Brisbane. The Warrego Highway suffered a lot of damage over the summer period, as a result of severe flooding. Consequently, roadworks are currently under way and frequently cause delays to traffic.

Roma is well-known for its avenues of bottle trees, planted in memory of those who lost their lives in past wars. Viewed from some angles, these quaint bulbous trees appear almost human-like, and it's for this reason I find myself feeling sad. This outback town in Queensland has lost several generations of fine young people. What a tragic waste!

At the present time, Roma is a thriving mining town (oil and gas), with a busy shopping centre and the most pedestrian-friendly roads I've ever experienced. I have to confess though, I'd much prefer to shop in Mitchell. I like the slower more friendly pace, and Mitchell has most things. I doubt we need ten or more varieties of individual items. In Roma, there seems too much of everything.

Therefore, next time I'm tempted to shop in Roma, I'll think again and most likely choose to stay snug in the loop of the Maranoa River. In other words, I won't cross the bridge!