Bio Control Flashcards
What principles of IPM does Biological control relate to and how?
Biological control is based on one of the aspects of the 1st principle of IPM which recognizes natural controls on herbivore populations. Other pest management strategies have to be adjusted to accommodate the use of biological control for crops to minimize impacts on the environment (5th principle of IPM). For example, you would not want to release a natural enemy of the pest you are trying to manage and then spray the same crop with a broad-spectrum insecticide. The overall pest management plan needs to function harmoniously in order to be effective.
What is Biological control?
Biological control is the use of populations of natural enemies to lower pest populations in a permanent or temporary manner.
What are the types of biological control?
Classical: using natural enemies from the native range of the pest to control an invasive pest;
Conservation: enhancing natural enemies pest suppression;
Augmentation: artificial increases of natural enemies
List methods of biological control that do not act through populations of live natural enemies.
Sterile insect males, Pheromones, Host-plant resistance, Biorational pesticides (Neem oil, insecticidal soap), and Transgenic pest-resistance crops
Briefly describe the targets, mechanisms, and steps of Classical Biological Control. Give examples.
Target: non-native invasive species;
Mechanism: The invasive species become high densities because local natural enemies are not specialized to the invasive species; Limited attack and not adequate control the pest; Introduction of specialized natural enemies that have evolutionary relationship with pest.
Steps: Collection of natural enemies, shipment, quarantine testing, release, monitoring, establishment, and impact evaluation.
Examples: Floating fern: Azolla filiculoides
Briefly describe the targets, mechanisms, and steps of Conservation Biological Control. Give examples.
Definition: Manipulation of farming practices to enhance pest suppression by populations of natural enemies
Goal: to minimize factors that harm NE and enhance features that make habitat suitable for NE
Assumption: NE already present can potentially suppress the pest given the opportunity
Valid for native insect pests, Not valid for invasive insects nor weeds
Briefly describe the targets, mechanisms, and steps of Augmentation Biological Control. Give examples.
Two characters:
- Inoculative releases: expectation to reproduce in the crop and offspring will continue control.
- Inundation or mass release: control will be achieved by the released individuals
Cost, Agent availability, Agent quality, Field effectiveness
Costs limit the use to:
NE is inexpensive to rear, Crop has high cash value, Cheaper alternative (insecticides) are not available
List farming practices that affect natural enemies.
Crop variety Removal of vegetation Ants protection Pesticide use Size of crop patches Dust foliage
List measures to enhance the habitat of natural enemies.
Physical refuges Provision of alternative hosts Planting ground covers Post-harvest management Manner and timing of harvest
List targets of biopesticides.
Fungi, virus, bacteria and nematodes, e.g. Bacillus thuringiensis is the best known example of biopesticides.
What groups of natural enemies are used for insects, weed control, and mites?
- For Insects: Parasitoids, Predaceous insects, Pathogens
- For weed control: Insects, Plant pathogenic fungi
- For mites: Predatory mite
Does biological control conflict with plant resistance?
Sometimes.
