What are biocontrol agents?
Biocontrol agents are organisms, or material derived from nature, which are used to manage pest problems.
They are often grouped into four main types of biocontrol agents:
- Macrobials are insects, mites and beneficial nematodes that when released will parasitize and feed on pests.
- Microbials contain bacteria, fungi, viruses and other microorganisms or their metabolites or cell fragments that have the capacity to kill pests or outcompete and prevent diseases.
- Semiochemicals are message-bearing compounds produced by an animals or plants that can be used to change and disrupt a pest’s normal behaviour.
- Natural substances obtained from plants, minerals and animals can have antimicrobial, insecticidal or pest repellent activity.
What are macrobials?
Macrobials, also known as invertebrate biocontrol agents, are natural enemies of pests. They include mites, insect predators, parasitioids and entomopathogenic (insect-killing) nematodes (or EPNs).
Useful background information on some key pests and their management with macrobial biocontrol agents can be found in the Applied Bionomics Bio-control Handbook. Some examples are provided below:
Examples of natural enemies
- Amblyseius swirskii: The predatory mite A. swirskii is one of the most successful commercial natural enemies in covered crops. It is a generalist predator and is used commercially to control the major greenhouse pests; thrips, whiteflies and mites.
- More information regarding this natural enemy can be found in the BioProtection Portal blog.
- An example of a successful application of the A. swirskii can be illustrated with a case study from Spain, where it has been used to control pests in honey melon, and also in aubergine production.
- Watch a video from Bionema to see how the predator A. swirskii actively manages the whitefly pest in the glasshouse.
Examples of entomopathogenic nematodes
- Steinernema carpocapsae utilizes an “ambush” strategy, waiting near the soil surface for target hosts
- Heterorhabditis bacteriophora has a “cruiser” strategy, seeking out its target.
- A successful example of the use of beneficial nematodes in the UK is the control of vine weevil in strawberries.
What are microbials?
Microbials are micro-organisms, including bacteria, fungi and viruses and may also include their metabolites or fragments of cells.
Examples of fungal biocontrol agents
- Trichoderma is a fungal bioprotection agent with multiple modes of action. Find out more about Trichoderma on the BioProtection Portal blog.
- Green Muscle™ is based on a specific isolate of a fungus called Metarhizium acridum which attacks locusts and grasshoppers. Find out more about Green Muscle on the CABI website.
Examples of bacterial bioprotection agents
Examples of virus bioprotection agents
What are semiochemicals?
Semiochemicals are chemicals emitted by organisms which act inter- or intra-specifically as a means of communication. They can act as attractants or repellants and have a specific, non-toxic mode of action.
Examples of semiochemicals
What are natural substances?
Natural substances are those materials derived from nature, or when synthesised are indistinguishable from the natural material.
Examples of natural substances
Storage, handling, timing and method of application of biological based approaches to pest management can be critical in ensuring efficacy of the product. Here you will find a selection of resources that will support you in maximising the impact of these agents in your production system.
Knowing the identity of your problem pest is critical to sourcing an effective means of managing the pest. Here we provide guidance and tools to help pest identification, and also potentially develop your diagnostic skills.
A more sustainable approach to the management of agricultural and environmental pests is the use of biological control (or biocontrol). Here we briefly explain the definition of biocontrol and the different types of biocontrol methods for managing pest problems.