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Photographs supplied by John Huth

The sculpture commemorates the destruction of the prickly pear by the Cactoblastis moth in Queensland and Northern New South Wales between 1926 and 1933.  It is a bronze sculpture of a prickly pear plant (Opuntia Inermis) with moth, caterpillars and egg sticks of the cactoblastis moth all enclosed in a clear acrylic case and mounted on a sandstone pillar.

The memorial was unveiled at Jubilee Dinner on 6 August 1985 of the Queensland Branch of the Australian Institute of Agricultural Science and presented to Miles and District Historical Society on 14 September 1985.

Acknowledged as one of the greatest biological invasions of modern times, the introduction and subsequent spread of prickly pear into Queensland and New South Wales had infested millions of hectares of rural land by the 1920s, rendering it useless for agriculture. Prickly pear proved so difficult and costly to control by chemical and mechanical means that enormous areas were simply abandoned by their owners.

Following mass rearing of cactoblastis, 10 million eggs were distributed in 61 localities throughout affected areas during 1926 and 1927 and a further 2.2 billion eggs were released between 1927 and 1931. Eggs were wrapped in paper quills together with pins to attach the quills to the pear plants. They were packed in boxes; each box contained 100 000 quilled eggs and printed instructions to guide landholders in the correct method of release. A fleet of seven trucks and 100 men distributed packed eggs across the state.  This insect proved to be spectacularly successful in destroying the weed.

By 1932, the stem-boring cactoblastis larvae had caused the general collapse and destruction of most of the original, thick stands of prickly pear. By 1932, almost 7 million ha of previously infested land was made available to 1165 settlers. Townships that had been stagnant in the 1920s were revitalised; public buildings, offices, shops and residences were built.


Address:Warrego Highway, Artesian Basin Centre, Miles, 4415
GPS Coordinates:Lat: -26.660011
Long: 150.197043
Note: GPS Coordinates are approximate.
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Monument Type:Sculpture
Monument Theme:Disaster
Approx. Event Start Date:1926
Approx. Event End Date:1933
Monument Manufacturer:Mrs Rhyl Inwood


Actual Monument Dedication Date:Tuesday 6th August, 1985
Front Inscription

Cactoblastis Cactorum Attacking Prickly Pear

Erected by the Queensland members of the Australian Institute of Agricultural Science to commemorate the destruction of 24 million hectacres of Prickly Pear by the caterpillar of the Cactoblastis Cactorum moth in Queensland and northern N.S.W. between 1926 and 1933 thus releasing this huge area for crop and pasture development.

This represents the most successful conquest of a plant pest by biological control in the world`s history - a tribute to scientific endeavour.

Source: MA,NRUM
Monument details supplied by Monument Australia - www.monumentaustralia.org.au