The pesticide Paradox in IPM Risk-Benefit Analysis

The pesticide Paradox in IPM

Risk-Benefit Analysis

IPM: is all about compatibility

Insecticides

Insecticide Definition

Any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest

(US EPA 2002)

It has been said in the 30s!

“Biological and chemical control are considered…as the two edges of the same sword…nature’s own balance provides the major part of protection…insecticides should be used so as to interfere with natural control of pests as little as possible”

(Hoskins et al 1939)

IPM remains compromising between:

• Environmental/human health advocacy

• Industries that need to use insecticides in order to prevent economic lost.

The impact of pesticides within IPM depends on:

• The pesticide

• The pest

• The management situation

Pesticides and Cotton

Boll-weevil eradication program

Pesticides are compatible with some IPM techniques

• Plowing

• Host-plant resistance

• Physical barriers

Pesticides and Bio-control

• Natural enemy resistance

Natural enemies tolerate different insecticides differently

• Variation observed within insecticides classes.

• Differential response of parasitoids versus predators.

Not only pesticides can interfere with IPM

Bacillus thuringiensisCinnibar moth feeding on tansy ragwood

Gypsy moth

Western Spruce budworm

• Fungicides and herbicides might affect natural enemies

Fungicides and Bio-control

Sub-lethal effects

• Natural enemies might produce

fewer viable eggs.

• Repellent effects

Colorado potato beetle and Colorado potato beetle and Beauveria bassianaBeauveria bassiana

Purple loosetrife, beetles and mosquitoes

Purple loosetrife Galerucella sp

Water Hyacinth weevils and herbicides

Insecticides are one of the four Insecticides are one of the four building blocks of IPMbuilding blocks of IPM

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IPMIPM

Improving pesticide selectivity

• Timing e.g. Apply before the arrival of natural enemies

• Placement e.g. Apply in first two thirds of plant only. Apply insecticide to the middle of every other row.

Pesticide application just next to seed.

Refuge!

Pesticides formulation might make a difference!

• Dust is more toxic to beneficials than wetable powders or emulsifiable concentrates.

Pesticides formulation might make a difference!

• Granular applications of certain pesticides do not reduce the number of natural enemies in certain crops but foliar applications of the same pesticide might cause substantial reductions.

Pesticides formulation might make a difference!

• Systemic pesticides will

protect some natural

enemies as well.

Pheromones are a good way to incorporate insecticide use in IPM

The greatest treath to many IPM programs is the misapplication of

pesticides