Beetle-fungi Alliance

Beetle-fungi Alliance : Recently, researchers from the Kerala Forest Research Institute (KFRI) uncovered a serious ecological and economic threat facing Kerala, which produces 90% of India's natural rubber. A destructive alliance between the ambrosia beetle (Euplatypus parallelus) and two fungal pathogens—Fusarium ambrosia and Fusarium solani , has begun decimating rubber plantations across the state.

• About Ambrosia Beetle : Belong to the wood-boring insect families. Found in Eastern Africa, India, Sri Lanka, China, Japan, Southeast Asia, Central and South America

o Feeding Behavior: Prefer dead or dying trees to cultivate ambrosia fungi, which serve as their primary food source.

o Attraction Mechanism: Drawn to trees that emit volatile organic compounds (like ethanol) when stressed or weakened.

o First reported in India in 2012 in cashew plantations of Goa.

o Recently detected in the Irrity-Kannur rubber belt of Kerala.

o Fungal Association: Carries fungal pathogens into host trees and cultivates them within tunnels (galleries) bored into the bark.

• About Fusarium ambrosia: It is cultivated by beetles inside host trees as a food source.

o Considered weakly pathogenic but plays a role in tree decline when beetles bore into stressed trees.

o Carried in mycangia (specialized organs) of beetles and inoculated into tree xylem.

o Reported in Asia, Africa, and recently in India, often associated with invasive ambrosia beetles.

• About Fusarium solani: Fusarium solani species complex (FSSC)

o A soil-borne fungus found globally and pathogenic to plants, humans, and animals.

o Plant Pathogen: Causes root rot, stem canker, and fruit rot in crops like legumes, cucurbits, and potatoes.

o Human Pathogen: Opportunistic infections in immunocompromised individuals.