Antibiosis

Definition

A form of amensalism in which one organism produces metabolic substances that are detrimental to another, causing injury, reduced fecundity, shortened lifespan, or death without the producer being affected. In entomology and biological control, antibiosis commonly refers to plant-mediated resistance in which secondary metabolites, trichome exudates, or induced volatile compounds directly impair herbivore development, feeding efficiency, or survival. The effect may be reversible or irreversible depending on dose and exposure duration.

Etymology

Greek anti- (against) + biosis (way of living)

Example

Cotton cultivars expressing high gossypol levels exhibit antibiosis against bollworm (Helicoverpa zea), causing larval mortality or extended development time that increases exposure to natural enemies.

Synonyms

• antagonism

Related Terms

• amensalism
• Allelopathy
• host-plant resistance
• antixenosis
• tolerance (plant resistance)
• Biological control
• secondary metabolite

Usage Notes

Distinguished from antixenosis (behavioral deterrence of feeding or oviposition) and tolerance (plant ability to withstand damage). Antibiosis is measured by fitness consequences on the herbivore, not by plant damage levels. The term is sometimes used more broadly in microbiology for any antagonistic chemical interaction, but in entomological contexts it specifically denotes adverse physiological effects on insects or mites.