Town’s old prickly problem
Reflecting on Chinchilla’s claim to cactus fame
CHINCHILLA wrote itself into the history books as the town at the heart of the eradication of the dreaded prickly pear.
It is hard to imagine today but by the 1920s there were more than 24 million hectares of Australia covered with prickly pear.
The cactus had been introduced into Australia in 1839 and by 1862 it had reached the Chinchilla area.
By the turn of the century it was increasing at a rate of 400,000ha a year.
Farmers tried to fight it by cutting and burning but their labours met with little success.
By the late 1920s grazing lands from west of Rockhampton to central NSW had been overtaken by this introduced pest from South America.
Up until the introduction of the cactoblastis moth, the best preventative measure for graziers to control the spread of prickly pear was spraying or injecting a poison called arsenic pentoxide, a toxic poison.
The sale of the chemical was controlled by the lands department and they supervised the use of it.
Most landholders had only an occupational licence in those early days, not freehold title of their land.
Land rangers, working for the lands department, monitored the improvements made by each landholder on the block he had selected.
If the prickly pear was allowed to flourish unchecked, land rangers would threaten to confiscate the land and reclaim it for the Crown.
This was just one more blow for the grazier who, after having cleared his block of trees to encourage the growth of pasture, now had the problem of encroaching cactus.
It was particularly bad in the heavy river soils and along water courses.
Some graziers were defeated by it and walked off their land.
However not all graziers viewed the cactus as a pest – with the threat of drought always looming on the farming horizon, graziers were turning to the cactus to feed their stock.
Some even worried that without it they would never survive another drought.
By 1932, then three-yearold Arthur Hurse remembers only the effects of the cactoblastis moth on the population of cactus around Chinchilla.
The stands of prickly pear had been reduced to an eerie forest of skeletons, white, frail and ready to disintegrate at a touch.
Many years later he recalls filling the back of his truck with pieces of cactus to feed hungry stock.
Over an open fire the long needles were scorched off to prevent injuring the mouths of cattle and sheep.
By this time the prickly pear was almost eradicated.
There remained enough of the cactus plants to keep the cactoblastis moth alive, which was important because after its first triumphant sweep not enough plants remained for the survival of the moth and a few years later there was a resurgence of the pear.
Scientists at the Bug Farm worked hard to produce more eggs from the cactoblastis moth, after that first reappearance and graziers purchased these as a “stick of eggs” to take home and dispense among the new cactus plants on their property.
The moth and its eggs were highly valued by this time and care was always taken never to harm or disturb these muchappreciated little workers.
The cactoblastis moth lays her eggs, about a hundred at a time, stacked one on top of the other in a little tower.
When the caterpillars hatch they burrow into the fleshy segments of the plant.
This dramatic transformation had taken place as a result of efforts by the Commonwealth Prickly Pear Board.
They imported 3000 eggs from Argentina and from these eggs were able to hatch enough female moths to lay more than 100,000 new eggs.
Half of these were sent to the Chinchilla Prickly Pear Experimental Station, later dubbed the “Bug Farm”, where scientists were to produce up to 14 million eggs a day to wage the battle against the prickly pear.
An information site on Clarkes Rd displays photographs and artefacts from the old Bug Farm.
WHAT A PEST: Prickly pear invades Chinchilla grazing land in the 1800s and early 1900s.