5.14 - Integrated Pest Management

Learning Objectives

I. Integrated Pest Management Defined

• Definition: IPM is an integrated approach, meaning a combination of different methods, to control pests.

• Goal: Minimize pesticide use and environmental disruption.

• Strategy: IPM relies on research and monitoring of the specific pests present, so that the approaches are targeted to those exact pests. That includes catching and identifying pests and factoring in things like weather and the pests’ natural life cycle.

II. Key IPM Methods

A. Biocontrol

• Definition: Adding a natural predator, natural competitor, or natural parasite to control the pest population.

• Application: Agents can be purchased (you can literally buy ladybugs in the mail) or attracted by planting habitat that naturally draws predators to the fields.

• Examples: Ladybugs control aphids, spiders control a wide range of insect pests, and parasitic wasps are effective against caterpillar species.

B. Crop Rotation

• Mechanism: Pests usually have one specific food source, so rotating crops (planting different crops in different seasons) keeps them from establishing themselves in the soil.

• Pests lay their eggs in the soil and the larvae need their preferred food source. Moving that crop each year prevents the population from getting established.

• Secondary benefit: Rotating lets fields stay planted for a longer portion of the year, which keeps weeds from establishing themselves in bare soil after a harvest.

C. Intercropping (Push-Pull System)

• Definition: Sometimes called a push-pull system because it uses two types of plants to strategically deter pests.

• Pull plant: A species like Napier grass that gives off chemicals attracting pests toward it, so they lay their eggs in that plant instead of near the cash crops. The pull plant can also attract natural predators of the pest.

• Push plant: A species like Desmodium that emits a chemical that deters pests from going near the crops.

D. Physical Methods

• Examples: Sticky traps, pheromone traps that lure insects in, row covers (fabric that keeps insects off the plants), hand-picking pests, and pulling or mowing weeds.

• Benefit: No chemicals at all, so there's no risk to non-target species or water.

E. Limited Chemical Use

• Spray only when needed: Farmers monitor pest numbers and only spray once pests pass an action threshold, the point where the damage would cost more than spraying.

• Targeted chemicals: Use the least toxic pesticide that works, sprayed only on the affected plants instead of the whole field.

III. Benefits and Drawbacks of IPM

A. Benefits

• Reduced pesticide use: This is the whole point of IPM.

• Protection of non-target species: Less pesticide means fewer deaths and mutations. IPM lowers the risks tied to:
• Atrazine, which can cause intersex frogs.
• DDT, which thins eggshells in eagles.
• Neonicotinoid insecticides, which can harm bees and other pollinators and are one of several factors linked to bee colony losses.

• Improved human health: Some pesticides are linked to cancer and other health problems, especially for farmworkers who handle them, so using less of them is better for human health.

• Water quality protection: IPM limits contamination of ground and surface water from agricultural runoff carrying pesticides.

B. Drawbacks

• Time-consuming and costly: IPM requires actively monitoring pest populations and doing specific research, which makes it more time-consuming and often more expensive to set up than just spraying a broad pesticide.

• Complex: Farmers need training to identify pests and their natural enemies, and the plan has to be adjusted for each crop, pest, and season.