Generally, three main types of biological pest control agents, or biopesticides, are used in pest control: microorganisms (or microbials), botanicals and semio-chemicals.

Microorganisms/microbials

Microorganism active substance means microorganism active substance that are microorganisms (protozoan, fungus, bacterium, virus, or other microscopic self-replicating biotic entity) and any associated metabolites, to which the effects of pest control are attributed. A microorganism active substance may contain viable and/or non-viable microorganisms. It can contain relevant metabolites/toxins produced during cell proliferation (growth), material from the growth medium, provided none of these components have been intentionally altered. (FAO/WHO, 2017)

Botanicals

Botanical active substance means a botanical substance that consists of one or more components found in plants and obtained by subjecting plants or parts of plants of the same species to a process such as pressing, milling, crushing, distillation and/or extractions. The process may include further concentration, purification and/or blending, provided that the chemical nature of the components is not intentionally modified or altered by chemical and/or microbial processes. (FAO/WHO, 2017)

Semiochemicals

Semiochemicals means substances or mixtures of substances emitted by plants, animals, and other organisms that evoke a behavioural or physiological response in other individuals of the same or other species. Different types of semiochemicals are:

• Allelochemicals produced by individuals of one species that modify the behaviour of individuals of a different species (i.e. an interspecific effect). They include allomones (emitting species benefits), kairomones (receiving species benefits) and synomones (both species benefit).
  
  
• Pheromones produced by individuals of a species that modify the behaviour of other individuals of the same species (i.e. an intraspecific effect).
  
  
• Straight-chained lepidopteran pheromones (SCLPs) are a group of pheromones consisting of unbranched aliphatics having a chain of nine to eighteen carbons, containing up to three double bonds, ending in an alcohol, acetate or aldehyde functional group. This structural definition encompasses the majority of known pheromones produced by insects in the order Lepidoptera, which includes butterflies and moths.
  
  (FAO/WHO, 2017)