Integrated pest management uses a variety of techniques in such a way that they do not conflict with each other. These techniques are chemical, cultural and biological. The skill to integrated pest management is to time the application of each technique for maximum benefit and minimum side effects.
Take an example. If you apply a chemical pesticide, you might kill harmful and helpful insects. So you are killing the friends that eat the pests. So in integrated pest management you study the life cycles of helpful and harmful insects so that you know when the harmful ones are present and apply a chemical pesticide then. In this way you kill the pests, but not the beneficient insects.
The benefit of using integrated pest management is that it prevents over-reliance on pesticides. At the moment there is a problem that pests are developing resistance to common pesticides. For example, the glasshouse whitefly, Trialeurodes vaporarium, has begun to become pesticide resistant in the south of Britain, and the resistance is spreading to other areas. The reason for this is that the pesticides have killed all the flies that are vulnerable to them, leaving those with some inbuilt resistance to that specific pesticide to breed and multiply. Using integrated pest management techniques minimises the use of pesticides, thus preventing the development of resistance. The other techniques will kill off pests. For example, no pest, for example, is immune to being crushed or eaten.
Cultural technques involve hygiene. In integrated pest management the grower ensures that all plant debris is disposed of , so that pests cannot hide in it, and that pots are disinfected in winter. This means that overwintering pests have no place to hide. All nooks and crannies in glasshouses are swept out and disinfected for this reason. Pests whose larvae dwell in the soil are vulnerable to cultural techniques. Vine weevil larvae are vulnerable to a ground roller, which crushes them. Digging exposes the cells in which some pests or their larvae overwinter, and then they are exposed to birds that can eat them. Blasting off aphids with water jets in summer not only destroys the aphids, but waters the plants as well. These techniques will be used at times when helpful insects are not present, as far as possible.
IPM might mean that you become aware of the presence of hosts in your land or area.Some species of aphid prefer a specific type of plant, maybe a tree, as a host for larvae at one stage in their life cycle. So therefore growers will as far as possible minimise the presence of host plants on their land. Conversely, they may adjust their land to create habitat for helpful creatures. For example,a pond with frogs or toads pays off enormously if you want slug control, as these amphibians eat slugs and snails. IPM might mean that growers introduce animals that, for example, eat slugs. Keeping a few ducks not only helps slug control but provides eggs. The problem slugs come back as eggs that you can eat or sell.
Intregrated pest management relies on the introduction of selected predators or the encouragement of natural ones. For example, ladybirds [Amercian ladybugs] are great eaters of aphids, so as far as possible they should be encouraged. Integrated pest management [IPM] will encourage hedgehogs and predatory birds. In glasshouses it will introduce, for example, Encarsia formosa, a minute parasitic wasp, to attack the red spider mite, Tetranichus urticaria. [Encarsia does not sting humans.] But when the wasps are being introduced chemical pesticides will not be used. You might use a chemical at a time before Encarsia is introduced, or when you are sure that it has died off, but during its presence then chemicals will not be used.Nematodes can be applied in gardens or glasshouses to destoy slugs. These are very tiny creatures that burrow into a slug's nervous system and paralyse it.
Furthermore, care in the use of chemicals is necessary. There are different kinds of pesticides. Integrated pest management will be reluctant to use residual pesticides, These remain in the soil and could therefore kill useful insects. Imidicloprid is one such soil based residual pesticide. It has proved useful in attacking pests, but there are concerns that it might kill helpful insects. The only type of pesticide that can be used is one that breaks up very easily. Slug pellets, will not be used, as they poison not only the slug, but also the hedgehogs and birds that eat eat them. Besides being counter-productive in inteprated pest management terms the use of non-organic slug pellets is horribly cruel, as the hedgehogs can be heard wailing in agony after eating them. However, organic pellets can be used, as they simply gum up the slugs' digestion. The slugs then starve to death.
Integrated pest management only works if growers are knowledgeable and prepared to research their crops and the pest problems specific to their area. IPM will then need a clear pest management plan. A lazy grower or one who wants to take short cuts to a fast profit will not be successful in IPM. The short cuts are the excessive use of pesticide, but they create long term problems. IPM requires that growers are aware of the full range of pest control techniques and judiciously select the ones that are relevent to their circumstances and apply them in a thoughtful, well-planned way. It is the most professional way of pest management.