Prickly pears -LRB- genus Opuntia -RRB- were imported into LOCATION@1 in the 19th century to be used as a natural agricultural fence and to establish a cochineal dye industry , but quickly became a widespread weed .

Prickly pears were taken to LOCATION@1 in the 19th century for use as a natural fence and for use in the cochineal industry .
