Integrated Pest Management (IPM) is a modern, sustainable approach that encourages the use of natural pest control mechanisms with the aim to grow healthy crops with the least possible disruption to agroecosystems and risks to human health and the environment.
As technology develops and scientific data accumulate, a growing number of classes of traditional chemical insecticides are found to be harmful to human health and the environment, as well as increasingly ineffective for combating pests. These problematic chemicals are deregulated and emerging alternatives are often pest-specific and applied in combination as part of a coordinated effort, called integrated pest management (IPM). Increasingly, growers and consumers alike recognize the need to manage pests in their environment, in a way that keeps their population size below a threshold level without harming other non-target organisms and humans that all co-exist in the agricultural environment.
It is no longer sufficient to spray one class of chemicals on an orchard and decimate all local insect life. Insect pests increasingly develop resistance to many classes of chemicals causing high degrees of resilience in the face of chemical spraying. After completion of a traditional chemical spraying programme, ecological niches remain available and the same pest which was targeted, or competing pests with similar biology, can emerge or travel from nearby areas to occupy the niche at higher population levels than were previously experienced. This leads to a steady annual increase in chemical costs under traditional chemical pesticide regimes, with reduced efficacy from year to year.
Increasingly, growers are called upon to implement a suite of control measures, all of which target the same pest from a variety of angles intended to keep pest population levels below the threshold at which damage occurs. Once this population is seen to surpass the threshold size, the grower can consider introduction of insect predators, parasites (natural enemies), or entomopathogenic (insect-killing) fungi, bacteria, or nematodes which attack the pest preferentially, and control their numbers by natural means. Often, these measures are used alongside chemical sprays, some of which are organic, in order to attack the pest from a number of angles simultaneously and ensure that its population levels are reduced in a long-lasting and sustainable way.
There are six major components which are common to all IPM programmes (see UC-IPM website for more details):
- Pest identification
- Monitoring and assessing pest numbers and damage
- Guidelines for when management action is needed
- Preventing pest problems
- Using a combination of biological, cultural, physical/mechanical and chemical management tools
- After action is taken, assessing the effect of pest management
IPM strategies practiced locally in South Africa include Sterile Insect Technique (SIT), Mating Disruption, Biological Control and Monitoring.