Introduction through Biological Control

Selected non-native species, usually predators and herbivores, are intentionally introduced in an effort to control the growth and spread of other introduced species. Grass carp, (Ctenopharyngodon idella) introduced to control unwanted aquatic plants in inland lakes resulted in native aquatic plant species being decimated. More recently, sterile hybrids (triploid grass carp) have been used successfully. In another case, the cane toad (Bufo marinus) was introduced to Australia by the sugar cane industry to control two pests of sugar cane. Only one-hundred-and-one toads arrived at Edmonton in North Queensland in June, 1935. They bred occurred almost immediately and within 6 months over 60,000 young toads were present. The toads are toxic and eat many species of both insects and vertebrates causing widespread ecological harm.