With precedents for patenting plants, animals, and microorganisms now established in the U.S., many companies are working toward expanding into markets with products based on bioengineered organisms. One example is the pesticide industry. Growing concerns about chemicals in the environment and increasing resistance of insects to chemical pesticides are spurring companies to consider other options. But, since the scope and strength of patents on living organisms has yet to be tested, industry is cautious about investing in production. In 1987, the worldwide market for pesticides reached nearly $17 billion, according to the National Agricultural Chemicals Association (NACA). Other industry sources say it is now approaching $20 billion. Herbicides and insecticides account for the largest percentage of sales, about 42% and 32% in 1987, respectively. Biopesticides—usually highly specific plant and insect toxins from naturally occurring or genetically engineered microorganismsare currently less than 1% of the t...