Biocontrol refers to the use of bilogical methods for controlling plant diseases and pests. In agriculture, there is a method of controlling pests that relies on natural predation rather than introduced chemicals.
The very familiar bettle with red and black markings the Ladybird, and dragonflies are useful to get rid of aphids and mosquitoes respectively. An example of microbial biocontral agents that can be introduced in order to control buterfly caterpillars is the bacteria Bacillus thuringenesis (often written as it.)
A bilogical control being developed for use in the treatment of plant diseases is the fungus trichoderma. Trichoderma species are free-living fungs that are very common in the root ecosystems. They are effective bicontrol agents of several plant pathogens.
Baculoviruses are pathogens that attack insects and other arthropods. The majority of baculoviruses used as biological control agents are in the genus Nucleo polyhedrovirus.