Penanggulangan dampak negatif pestisida

• Pencegahan/preventif– Rotasi penggunaan pestisida (berbeda bahan

aktif, berbeda cara kerja)

• Penanggulangan– Resistensi (

• Management by moderation,• Saturation• Multiple attack

– Resurgensi (Spesifik sasaran (Narrow spectrum)

Penanggulangan dampak negatif pestisida

Resistance

Resurgence

Secondary pest out break

Insecticide Resistance Management

1. Integrate chemical control with other tactics.

2. Treat only when needed.3. Time the application against the most

susceptible stage.4. Use only the recommended rate and

good application method.5. Don’t rely on a single class of insecticide.

Insecticide Resistance Management

6. Don’t mix insecticides for the same target insect.

7. Rotate Insecticides8. Apply the insecticide only to the areas of the

field that need it.9. Avoid persistent formulations of an insecticide.10. In the event of a control failure, check your

method of spraying first.

Resistance Management

• Strategy– Saturation– Moderation– Multiple Attack

• Tactics– Prevention– Reversal

Saturation:High value of crop, saturation of defense mechanism

-Higher dosage (If recessive gen resistance, systemic, hormonal MoA)

-Suppression detoxivication by synergists (piperonil butoxide, sesamine)

The process has three general stages, each with its own Management Strategy

Prevention

Man

age

or

Rev

erse

Abandon Pesticide/Management Tactic

Need to monitor

resistance

Moderation:

-Low dosage: preserved susceptible gen

-Less frequent applicaions

-Short persistance

-Avoidance of slow release formulation

-Selection direction mainly against adult

-Localized application

-Preservation of refugia

-Higher treshold

Multiple attack:

-Mixture of chemicals

-Alternation of chemicals

Specific Tactics

• Prevention– Use pesticides only as needed– Time/target applications precisely– Combine chemical & non-chemical controls

• Reversal– Cease use of pesticide causing resistance. Problems

• Probably the preferred control• May be used for other pests• Area-wide enforcement usually necessary

– Refugia– Use synergists– Genetically manipulate the pest population (Gene

Driving)

Using Nonpersistent insecticides

• Break down rapidly into harmless and water soluble products, once released into the environment.

• Two classes of widely used nonpersistent insecticides: – Organophosphates– Carbamates

• Both are neurotoxins

Using narrow-spectrum insecticides

• Broad-spectrum insecticides kill a wide range of insects, including many that are beneficial.– Examples: organochlorinated hydrocarbons,

most organophosphates.

• Narrow-spectrum insecticides are toxic to only a few types of insects.– Examples: most carbamates.

Resistance Management …

• … tries to maintain the usefulness of an insecticide.

• … attempts to manage target pests after resistance has led to control failures.

• Managing resistance begins with recognizing the factors that influence resistance development ...

• Biological factors that favor resistance development:

– Little or no migration between populations– Insect species is monophagous (feeds on

only one plant species)– Insect species has a short generation time

• “Operational” factors that favor resistance development: – Treatments provide prolonged exposure to the

insecticide (via frequent sprays, long residual, or controlled releases)

– Selection pressure is high (high mortality in the treated portion of the population)

– No refuges exist (for susceptible insects – and their genes – to survive)

– Large areas are treated

All of the factors listed above intensify selection.

Detecting / monitoring resistance

Many papers stress the importance of detecting and monitoring insecticide resistance. Although monitoring can be useful, it is important to determine the exact goal of monitoring and assess whether or not it can be met. Purposes include ...

– explanation of control failures – determination of insecticide choice for a single field (field kits)– determination of the success of resistance management efforts ...

have resistance frequencies dropped or stabilized? – detection of resistance at an early stage so that management

efforts can begin ... This approach is a problem because statistical probabilities mean that bioassays must contain very high numbers of insects in order to provide detection before the momentum of resistance development is too great.

• So ...

Resistance management must begin before detection efforts confirm that resistance development is underway. What can be done in resistance management?

Resistance management techniques

• Minimize selection pressure – to keep susceptible insects alive ... the idea here

is that genes for susceptibility are a valuable natural resource that should be maintained.

• No unnecessary treatments• Lowest possible effective rates• Shortest effective residual • Local instead of area-wide treatments (including spot

treatments)• Preserve untreated refuges• Use other controls whenever possible (cultural

practices and host plant resistance)

• Kill the developing resistant population – High dose strategy (a well-chosen dose to kill

rare heterozygotes) Dose must remain high (happens only in transgenics) ... what environmental impacts?

– Synergists to neutralize resistance (for metabolic resistance)

– Mixtures or rotations of insecticides ... to kill those insects that are developing resistance to one compound by using a different one.

• So far, minimizing use is the only strategy really proven to work satisfactorily. Rotations involve no extra cost, so they represent a good idea even if they are unproven.

• Despite their popularity with pesticide manufacturers and distributors, mixtures and high doses usually involve too many negatives to be practical for insecticide resistance management.

– This differs in managing insect resistance to transgenic plants.

Diamondback Moth: A Leader in Insecticide Resistance

Some populations of DBM have become resistant to:• DDT (1953)• Organophosphates• Carbamates• Pyrethroids• Proteins in Bt (Cry 1A and Cry 1C)• Growth regulators (e.g. diflubenzuron)• BPU (chitin synthesis inhibitors)• Spinosad• What is next?

We Have the Tools to Manage DBM