美国马里兰州哥伦比亚市的 IGENE生物工艺公司从贝壳中提炼出一种称为Clando San 的杀虫剂。该杀虫剂适于草地、苗圃、果园和蔬菜上对线虫的防治。它与化学剂杀虫不同。Clando San 不直接杀虫,而是促进土壤微生物产生一种杀死线虫和虫卵的酶。该药的有效成分是一种蟹壳、虾壳、小龙虾壳和其它水生贝壳动物的壳中蛋白质和几丁质的天然混合物。该产品不溶于水,从而有效地防止地下水污染。1988年3月份已开始在市场上销售。 IGENE Biotechnology, Inc. of Columbia, Maryland, USA, extracts a shell-called pesticide called Clando San. The insecticide is suitable for controlling nematodes on grass, nursery, orchard and vegetable. It is different from chemical pesticides. Instead of killing insects directly, Clando San promotes soil microbes to produce an enzyme that kills nematodes and eggs. The drug’s active ingredient is a natural mixture of protein and chitin in the shells of crab shells, shrimp shells, crayfish shells and other aquatic shellfish. The product is insoluble in water, thus effectively preventing groundwater pollution. March 1988 has begun sales in the market.