What pest management alternatives do we have to pesticides? Doing nothing is often the most cost effective option. Tolerate some damage and let nature take its course. It is the goal of Integrated Pest Management (IPM) to manipulate the biological components of the system to prevent or suppress pests and minimize the need for purchased inputs. Selection of plants for their resistance to pests, termed host plant resistance, is the first line of defense against pests and is not used nearly enough. Substituting plant species or cultivars that are less susceptible to pests will reduce the need for controls. Plant choice often is based on characteristics other than pest profiles. However, when the choice to buy or grow a plant is made, the pest problems and potential problems are also obtained.
Biological control, the second line of defense against pests, is the use of natural enemies of pests to keep them below economically important levels. Conservation of competitors, antagonists and natural enemies by judicious use of pesticides is extremely important. Augmentative releases of mass reared predators is also an option. However, the haphazard release of natural enemies is not recommended.
Cultural and management practices are the third line of defense against pests. Proper plant care including nutrients, water and sunlight maintain vigorously growing plants that are less susceptible to pests. Strict sanitation should be practiced in propagating and growing plants. Use practices that exclude pests and prevent their spread. Heavily infested and damaged plants should be removed and destroyed. Mechanical control using hands or machines to remove pests such as caterpillars or pruning plants to remove aggregating aphids on plant stem tips can be effective. High pressure water sprays will knock soft-bodied pests such as aphids and mealybugs to the ground where they may starve or be eaten by their natural enemies.
Biorationals such as soaps and oils: botanicals such as neem products; growth regulators such as Enstar, Logic and Precision; microbial products such as those of Bacillus thuringiensis (B.t.); and nematodes all have a role in IPM and can be used in the place of conventional chemical pesticides. However, these are remedial controls and prevention is more preferred.
There are several "cardinal rules" which practitioners of IPM should follow.
One control option is to do nothing and just let nature take its course. Most pest populations suffer high natural mortality. However, eradication is often impossible and is undesirable because of the need to sustain natural enemies.
Another option is "spot treatment" where controls are applied only to the plants infested. Maintain adequate records of pests, plants and action taken, together with a follow up assessment. Prevention measures are often more effective than remedial efforts to control high populations. The easiest way to avoid pest problems is to eliminate the plants most susceptible to pests through a host plant resistance strategy. When chemical pesticides are selected, insure that the proper chemical and rate are applied, using correctly calibrated equipment with adequate coverage of the target. Rotate chemicals so that the same chemicals are not used repeatedly over a long period of time. Whenever possible, promote biological control agents (natural enemies) and use alternative controls that are less toxic to nontarget organisms and the environment such as soaps, oils, growth regulators, microbials or nematodes.