The cane toad (Bufo marinu), is a large, terrestrial toad native to Central and South America. It was introduced to Australia by the sugar cane industry in 1935 in an attempt to control beetles that were damaging the sugar cane. This was done against the recommendations of many scientists at the time and was subsequently proven to have been exceedingly ill-judged.
Thousands of toads were released without any scientific testing on the breadth of their diet, and they not only failed to control the beetle, but turned their carnivorous attention to any creature that was small enough to be swallowed – becoming a significant problem themselves. Without their own natural enemies and thanks to some formidable defences, they were able to spread rapidly.
Although it was carried out in the name of biological control, today’s practitioners consider this release to have been a highly irresponsible act. With today’s stringent regulation and extensive scientific testing, the introduction of the cane toad would not be allowed.
Societal values have also changed; we now value native species’ biodiversity far more highly than perhaps ever before. In fact, biological control today is often used to increase species biodiversity.