Other than chemical control of pests, what are other ways to control insects or diseases?
There are four basic approaches to pest control other than chemical. 1. Cultural control means growing healthy plants since stressed plants are more susceptible to pests. Plants that are water stressed, i.e., too much or too little water, or plants that are starving for nutrients, will be more susceptible to disease and insect attack. As an example, some pine trees give off a chemical when they are water stressed. A beetle is attracted to this chemical and will subsequently lay eggs in the tree bark of the tree and cause damage.
Sanitation is also a part of cultural control. Often it is helpful to simply remove diseased leaves and discard them, or remove the diseased plant among healthy ones.
2. Physical and mechanical control -- this may include using a flyswatter, screening out pests, washing insects off a plant with a hose, or skirt pruning to keep some ground pests, such as snails, out of trees. In this case, once the trees are skirted, the trunk becomes the only access way into the tree. Wrapping a copper band around the trunk will repel snails from climbing into the tree.
3. Biological control – a.) the use of parasites, such as tiny wasps which lays their eggs inside other insects, and b.) predators like ladybird beetles and praying mantis. Certain fungi, bacteria, viruses and nematodes are also used to control many insect pests.
4. Biorational control -- the use of soaps, oil, insect growth regulators and, what is referred to as soft or natural insecticides; those that are friendlier to the environment such as neem oil, pyrethrums, rotenone and Bt.
