Beauveria bassiana

Introduction

Beauveria bassiana is a naturally occurring fungus that infects and kills a wide variety of insect pests. Used as a biopesticide in agriculture, it offers an effective and environmentally safe alternative to chemical insecticides. Beauveria is especially important in integrated pest management (IPM) systems, helping control pest outbreaks without disrupting beneficial insect populations or causing residue issues.

Scientific Description

Beauveria bassiana is an entomopathogenic (insect-infecting) fungus from the family Cordycipitaceae. Its spores (conidia) attach to the cuticle of insect hosts, germinate, and penetrate the exoskeleton. The fungus proliferates inside the insect body, killing it within 3–7 days, then sporulates on the cadaver, producing new infective conidia.

Key biological mechanisms:

• Infection via Cuticle: Enzymes like proteases, chitinases, and lipases dissolve the insect’s outer shell.
• Toxin Production: Releases beauvericin and other mycotoxins that paralyze or kill the host.
• Systemic Infection: Colonizes internal organs and hemolymph.
• Spore Reproduction: Spores spread through contact or environmental dispersal, enabling secondary infections.

Benefits

• Effective Against Wide Range of Insects: Targets aphids, whiteflies, thrips, beetles, borers, caterpillars, grasshoppers, termites, and more.
• Minimal Non-Target Impact: Does not harm bees, earthworms, or vertebrates.
• Safe for Organic Farming: OMRI-listed and certified for use in many organic programs.
• No Resistance Development: Insects are unlikely to develop resistance due to its biological mode of action.
• Works in Synergy: Can be combined with neem, Bt, or microbial consortia for broader coverage.

Uses

• Target Pests: Whitefly (Bemisia tabaci), aphids, thrips, mealybugs, stem borers, fruit borers, shoot flies, beetles, weevils.
• Crops: Cotton, tomato, chili, brinjal, sugarcane, pulses, banana, tea, coffee, floriculture.
• Application Methods:
  • Foliar spray: 5 g/L or 5 mL/L of water with a wetting agent
  • Soil drench: Against soil-dwelling stages like grubs and pupae
  • Seedling root dip: To protect young plants in nurseries
• Optimal Conditions: 20–30°C, high humidity (>70%) for infection to succeed
• Reapplication: Every 7–10 days during active pest pressure

Trivia

• Named after Jean Beauverie, who first described the fungus in 1911.
• Naturally found in forest soils and insect cadavers.
• Also used in post-harvest pest control of stored grains in some regions.
• Can colonize plant tissues as an endophyte, providing systemic resistance.