PLNT2011: Integrated Pest Management Notes

Integrated Pest Management (IPM)

Course Overview

• This course covers various aspects of plant and environmental health, including:
  • Soil biology and nematodes
  • Insect pests and beneficials
  • Weeds and their ecology
  • Vertebrate impacts
  • Plant pathology
  • Biotechnologies
• The central question is how to integrate all these elements into Integrated Pest Management (IPM).

Antecedents of IPM

• The previous focus was primarily on the destruction of pests.
• However, it's crucial to consider what happens in nature.
• Chemical control has led to resistance in pests and off-target damage.
• Understanding pest biology is essential for mitigating their impact, leading to the birth of Integrated Pest Management.

Know Your Enemy (or Friend)

• **Insect Metamorphosis: ** * Ametabolous: No metamorphosis (Egg -> Adult).
  • Hemimetabolous: Incomplete metamorphosis (Egg -> Nymph/Naiad -> Adult).
    • Example: Naiad emerges from water to become an adult.
  • Holometabolous: Complete metamorphosis (Egg -> Larva -> Pupa -> Adult).

Insect Mouthparts

• Chewers:
  • Examples: Grubs, grasshoppers, caterpillars.
  • Significance: Cause direct damage to plant tissues by chewing.
• Suckers:
  • Examples: Psyllids, aphids, bugs.
  • Significance: Extract plant sap, transmitting diseases and weakening the plant.

The Question of Spraying

• The core question is whether or not to use chemical sprays.

Limerick Example

• A limerick illustrates biological control:
  • A ladybird in Kearney’s Spring consumed aphids and mites, making biological control her thing.

Intervention Impacts

• Negative Impacts of Interventions:
  • Killing natural enemies.
  • Impacting human health.
  • Entering waterways.
  • Increasing pest resistance.
  • Reducing market access.

Specific Plant Diseases

• Chlorotic Streak Disease.
• Rubber Leaf Drop.
• Pasture Dieback.
• Bacterial Wilt.

Integrated Pest Management (IPM) Components

• IPM integrates various control methods:
  • Cultural
  • Biological
  • Chemical
  • Physical
  • Genetic
  • Social
• No single method works in isolation; IPM enhances sustainability and efficacy.
• Record Keeping: Maintaining detailed records is crucial.

Chemical Control

• Hard Options:
  • Contact chemicals targeting the nervous system (e.g., organophosphates, neonicotinoids).
• Soft Options:
  • Agents that only work upon ingestion.
• Calendar Spraying:
  • Considered a harmful chemical application method.

Biological Control

• Promoting beneficial organisms (e.g., NTF, Pasteuria).
• Approaches:
  • Inoculative release.
  • Inundative release.
• Biocontrol microbes (e.g., Metarhizium, Bacillus thuringiensis, viruses).
• Landscape management to support beneficial organisms.

Gold Standard in IPM: Prickly Pear and Cactoblastis

• The successful control of prickly pear cactus using the Cactoblastis cactorum moth is considered a gold standard in IPM.

Cane Beetle and Cane Toad Example

• The cane toad was introduced to control cane beetles, but it had unintended consequences.
• Mungomery RW (1935) noted that experience in other regions suggested no serious harm was likely, but this proved incorrect.

Cultural Control

• Techniques:
  • Crop rotation.
  • Promoting passage of beneficials (e.g., bamboo between mango trees).
  • Companion planting (e.g., guava against Asian citrus psyllid and huanglongbing).
  • Lures.
    *Improving overall plant health through better nutrition.
  • Plants uptake microbes from soil.
  • Plants use them for nutrients.
• Plants can also consume proteins.
  • White et al (2018) described the Rhizophagy Cycle as an oxidative process for nutrient extraction from symbiotic microbes.

Physical Control

• Methods:
  • Flooding.
  • Barriers.
  • UV light.
  • Tillage.
  • Traps.
  • Hand removal.
• Example: The Rabbit Proof Fence.

Genetic Control

• Techniques:
  • Traditional or marker-assisted breeding for resistance.
  • Introgression of resistant alleles.
  • Genetic selection (e.g., pigeon pea).
  • Genetic modification (e.g., Bt cotton).
  • CRISPR-Cas9 editing of genes.

Crop Performance Rating

• Rating crops for performance against diseases and pests is essential for variety selection.
• It provides information for breeding programs.
• Example: CSD (Chlorotic Streak Disease) Ratings (2012-2014).

Public Awareness/Extension

• Need to engage with stakeholders.
• Tailor communication to the audience.
• Keep the message simple and clear.
• Ensure the message reaches key decision-makers.

Molecular Technologies

• Molecular diagnostics for pathogen/pest detection.
• Environmental monitoring of interventions.
• Germplasm screening for SNPs and other polymorphisms.
• Genetic transformation with traditional technologies.
• RNAi technologies.
• Other CRISPR-Cas9 applications, Artificial Intelligence?

IPM Key Points

• Accurately identify, monitor & RECORD pests.
• Assess biological activity and respond to economic thresholds.
• Strategically change chemistries.
• Promote beneficials, good cultural practice, and plant health.
• Mobilize stakeholders.

Conclusions

• Many pests are context-driven.
• Climate change is altering pest management.
• Control of pests can be difficult and dangerous.
• Silver bullets are best reserved for werewolves.
• Integrated Pest Management (IPM) is dynamic and offers the most promise for sustainable management of pests.