These successes are due, in part, to new regulations introduced in the 1970s, which required more vigorous testing for biocontrols (although the earlier cactus case ultimately worked, it followed a limited release of another insect that had to be destroyed because it had a taste for pineapple). Researchers had to find biocontrol candidates that were host-specific, decreasing the likelihood that they would start feeding on native species. According to Johnson, the process for testing biocontrols for forestry use involves testing 50-100 representative plant species at a cost of at least $1 million dollars. The process is slow, too, usually taking from five to 20 years for approval. Since the regulations went into effect, there have been more than 50 biocontrols released in Hawaii, none of which have hurt any organisms they weren't meant to.