Chinchilla Library Service

Heritage Fact Sheets

The Prickly Pear Era - the Cactoblastis Story

Opuntia inertia Opuntia inermis - Prickly Pear

As the lands of the Chinchilla region began to be opened up through the government's policy of closer settlement, selectors moved out to take up their blocks averaging about 640 acres. There was one element that they would have to battle for years if they were to survive on their lands - the menace of prickly pear - the 'Green Hell'. Only those who lived through those times could have any real knowledge of its devastating impact and the hopelessness it engendered among the embryonic farming communities of the area.

Prickly pear was the great destroyer of lands and hopes. It grew in such thick and abundant profusion and was so difficult and expensive to clear that it ruined the dreams of families and ravaged the land. So powerful was its intrusive growth that many hopeful selectors and their families were forced to abandon their hard-won selections. In the Chinchilla district, the problems associated with prickly pear were immense, and vast tracts of the shire were infested with its growth, an infestation that very severely affected the decelopment of the district.

Some say Matthew Goggs was responsible for transporting prickly pear to the district on the back of a bullock dray, where it was planted in the Chinchilla station garden. By 1879, the pear was beginning to get out of control. By 1893 it was reported in NSW that there were very serious concerns and many thousands of pounds had already been spent in attempting to eradicate it. In 1895 it was added to the list of noxious weeds in Queensland and in 1899 an entomologist advocated that some kind of natural enemy should be introduced to combat its spread.

By 1920 60,000,000 acres were infested and it was spreading at the rate of 1,000,000 acres annually. Nothing was able to stop it - no birds or insects affected it, and chemical and other controls were ineffective. Chinchilla was in the very heart of pear-infested country. The lands around the shire were, in places, completely impenetrable. The cost of killing the pear was greater than the value of the land it was infesting.

Methods used to combat prickly pear:

  • chopping it
  • drying & burning it
  • injecting it with poison (arsenic, common salt & caustic soda)
  • injecting it with chlorine gas
  • digging it up
  • burying it

Pharoah & Sons of Chinchilla were the patentees and manufacturers of a concoction called 'Perfection Pear Poison' which sold for 13/6 per 5 gallon drum and 15/- in powder form. it is not known how effective this poison was in killing the pear.

In 1912 the Travelling Commission was formed to enquire into any natural enemies of the pear in other countries, and to investigate any commercial uses of pear. The Dulacca Experimental Station was opened. In September 1913 the Prickly Pear Commission returned to Australia from the Americas bringing back a small batch of Cactoblastis cactorum caterpillars and cochineal insects. However all the Cactoblastis died. It became obvious after years of experiments that some form of biological control would be the answer.

In 1924 the Prickly Pear Land Commission was formed to work effectively with local authorities. Experiments with cochineal insects were continuing. Chinchilla was the centre of the prickly pear menace, so it was obvious that the region should be used as one of the principal areas for experimentation in biological control. Alan Dodd was head of the biological section of the Queensland Lands Department.

In 1924 he had been in charge of the experimental research station at Chinchilla, the 'Bug Farm', which he handed over to Alan R Taylor. The Bug Farm was situated on a property name The Shanti, owned by Thomas A Cole on the west side of Charley's Creek about 3 miles from Chinchilla.

Dodd brought home 3000 Cactoblastis eggs from Buenos Aires to Sherwood, Brisbane in specially designed wooden boxes with side handles for carrying with high sloping roofs. They were well-ventilated with brass gauze and mesh steel wire. The bottoms of the cases were covered with sterilised and moist sphagnum moss with cut prickly pear, as food, wedged into it. These were the only Cactoblastis insects ever imported successfully into the country.

By September 1925, 100,00 eggs were stored at Sherwood and Chinchilla, yielding an increase of over 900% in twelve months. The first release was at a property at Chinchilla (Harling's) where the pear was completely destroyed. During the height of the battle, dozens of men were employed at the Bug Farm as they bred and readied eggs to be released throughout Queensland and New South Wales. Alan Dodd was the agricultural saviour of the state.

The Cactoblastis cactorum insect was the most powerful of all controls ever placed into effect against the plague of prickly pear. In 1932, the Prickly Pear Land Commission reported that the problem of prickly pear was solved. Vast tracts of land, previously taken up and then abandoned, were now once again being selected, and areas still under pear were slowly being cleared by the insect.

On 22 February 1936, the Boonarga Cactoblastis Hall was officially opened. This Hall is now on the National Estate Register and is one of only two known buildings in the world dedicated to an insect. The defeat of the pear menace led to a great sense of optimism in Chinchilla and an unprecedented development of farming and agriculture in the Chinchilla Shire. In 1962 Alan Dodd was award the OBE.

Today, paradoxically, the fruit of the pear is still highly prized for jam-making, but there are other applications for which the plant has proved useful in the past. Matthew Goggs or his cook made pies out of the fruit and mixed it with apples and rhubard. Children also enjoyed jellies made from the fruit. The juice from the ripe fruit has been used as a kind of household paint and as a timber preservative. The thorns have been used as gramophone needles. The juice made an adequate ink. It has even been used for a cough medicine.

Source: Footsteps in Time / Dr Tony Matthews
remains of johnty turner's cottage Remains of Johnty Turner's cottage, overrun with prickly pear
combatting the pear Combatting the prickly pear
cactoblastis cages at the bug farm Cactoblastis cactorum cages at the Chinchilla Field Station
cactoblastis eggs A pile of Cactoblastis eggs at the Chinchilla Field Station
weighing cactoblastis eggs

Cactoblastis eggs being weighed at the Chinchilla Field Station