Lecture 18 - Invertebrate Pests

Overview of Lecture
  - Introduction to invertebrate pests, focusing on insects and a few other invertebrates.
  - Discussion of common pests found in urban and rural gardens and landscapes.
  - Importance of beneficial invertebrates in the garden.
  - Emphasis on pest management approaches that reduce reliance on chemical pesticides and promote natural balance.

Student Learning Outcomes
  - Focus on cultural practices affecting plant health and development.
  - Review symptoms and signs of plant damage from invertebrate pests.
  - Examine common Integrated Pest Management (IPM) practices to formulate solutions.

Introduction to Integrated Pest Management (IPM)
  - Definition of IPM: An eco-based approach aimed at minimizing hazards to human health, domestic animals, wildlife, and the environment.
  - Importance of Identification:
    - The first step in an IPM program is proper identification of pests and beneficials.
    - Identifying whether an insect is a pest or beneficial informs management strategies.
  - Prevention: Emphasizes proactive management to minimize pest issues before they arise.

Characteristics of Invertebrate Pests
  - Pests may feed on plants or plant parts. Types of mouthparts include:
    - Piercing/Sucking Mouthparts: Examples include aphids and mosquitoes; can transmit diseases between plants.
    - Chewing Mouthparts: Examples include caterpillars and grasshoppers.
    - Other Mouthparts: Some insects siphon or sponge out plant juices.

Benefits of Invertebrates in Gardens
  - Generalist predators like spiders and lady beetles help control pest populations.
  - Soil-dwelling organisms like certain mites improve soil health by breaking down organic matter.
  - Important Beneficial Invertebrates:
    - Spiders: Effective predators that help in pest control.
    - Lady Beetles: Commonly referred to as ladybugs; feed primarily on aphids.
    - Lacewings: Predatory insects that act effectively against aphids and caterpillars.
    - Parasitic Wasps: Inject eggs into host pests (e.g., aphids), leading to pest population suppression.

Biological Control in IPM
  - Definition: Biological control refers to the suppression of pest populations by their natural enemies.
  - Introduction of beneficial insects (augmentation) must be paired with environmental support for longevity.
  - Example of successful biological control:
    - A landscape installation attracted various beneficial insects simply through habitat provision during planting.

Integrated Pest Management Cycle
  - 1. Knowledge: Identify pests and beneficials; understand management options.
  - 2. Cultural Practices:
    - Soil preparation, plant selection, irrigation management, and keeping plants healthy to prevent infestations.
  - 3. Mechanical Control:
    - Manual removal of pests, hosing off infested plants, and pruning.
  - 4. Biological Control: Utilize natural predators and parasitic organisms as alternatives to chemicals.
  - 5. Chemical Control: Use as a last resort when other methods fail; spot treatment rather than widespread application.

Monitoring and Documentation
  - Evaluate Management Strategies: Assess effectiveness of pest management strategies to inform future actions.
  - Document Environmental Conditions: Record data on pests, plants, and environmental conditions to build knowledge for future prevention.

Invertebrates in Focus
  - Introduction: The study focuses on arthropods and their importance in pest control and soil health.
  - Key Groups of Invertebrates:
    - Crustaceans: E.g., woodlice (roly-polies) that feed on decaying organic matter. Generally not serious pests; indicate damp conditions.
    - Millipedes: Function as decomposers; typically not problematic except in high humidity or if introduced to worm bins.
    - Centipedes: Generalist predators of other insects, able to consume smaller insects; typically not harmful to humans.
    - Symphyla: Small soil-dwelling creatures; indicators of healthy soil ecosystems.
    - Arachnids vs. Insects: Key differences include body structure (eight legs in arachnids vs. six in insects), feeding habits, and ecological roles.

In-depth Examination of Pest Specifically Slugs and Snails
  - Cultural Management Strategies:
    - Downsize moisture levels; choose plants less attractive to slugs/snails.
    - Use barriers like copper around vulnerable plants.
  - Chemical Control Consideration: When needed, iron phosphate recommended as a low-toxicity solution for pest management, balancing safety and effectiveness.

Conclusion
  - Emphasis on fostering beneficial organisms through planting and habitat creation to maintain balance in pest control methods.
  - Recap of the importance of responsible pest management through integrated strategies that minimize harm to both beneficial organisms and the environment.