Biological control is an essential tool against invasive plants and animals, but stricter laws are needed to ensure that it doesn't inadvertently harm native organisms, two prominent ecologists say. "Biological control (BC), the science and technology of controlling pests with natural enemies, has had several recent successes, including suppression in Africa of invading mealybug and whitefly pests of cassava by means of introduced wasps," the scientists write in the Policy Forum section of the June 16 issue of the journal Science. "However, BC is not a panacea, and without careful use, it can misfire." For example, introduced enemies don't always stay where they are put. Or they can have broad appetites that extend beyond the target pests to nontarget native plants and animals, write Donald Strong, a UC Davis professor of evolution and ecology, and Robert Pemberton of the U.S. Department of Agriculture's Invasive Plant Research Laboratory in Fort Lauderdale, Fla. Strong, an authority on the use of biological controls, warned about the risks of the practice in Science on Aug. 22, 1997. This time, he and Pemberton point out that biological-control activities in the United States are regulated by antiquated federal laws written 26 to 88 years ago. "Native plants and animals are not well protected by laws or regulations, and the deficiency is particularly serious in terms of organisms imported for biological control against insects and other animals," Strong said. "These species are chosen to be imported because of their potential to seriously harm the target species. If the imported agents are not specific, they can also threaten natives. "We need laws specifically dedicated to protecting our native plants and animals against these particularly threatening immigrant species." In the Science article, the scientists suggest that the regulatory process be strengthened to require assessments of the potential impacts on all native organisms, and that more experts be consulted. "All proposed introductions of herbivores and carnivores should meet criteria of need, appropriateness, predicted efficacy and ecological safety," they write.