The use and potency of pesticides is far greater today than it was in the 1940's. The adverse effects of pesticides, in terms of human health problems and general environmental damage, is a cost only now being recognised. Many strategies are being developed to reduce the use of pesticides, primarily integrated pest management in agriculture, new biological control mechanisms in agriculture and the development of transgenic crops, host plant resistance to insect pests, disease resistance in plants, durable resistance and what are now called cultural control methods.