Context: Kerala Forest Research Institute has identified a serious threat to rubber plantations in Kerala from an invasive species- the Ambrosia Beetle, in mutual association with two fungi: Fusarium ambrosia and Fusarium solani.
Relevance of the Topic: Prelims: About Invasive Alien species, Ambrosia beetles, Rubber Plantations in India.
As per the official data of 2024, India is the world’s fourth-largest producer of rubber in the world. Kerala alone accounts for 90% of India's total production and 72% of its rubber cultivation area. Threat to rubber plantations in Kerala from an invasive species- Ambrosia Beetle, is a serious concern.
Ambrosia Beetles
- Ambrosia Beetles is an Invasive Alien species.
- Native to Central and South America.
- First reported in India in the cashew trees in Goa in 2012.
- The name Ambrosia is not taxonomic but ecological. They get their name from the ambrosia fungi that call the beetle their home.
- Have a mutual association with 2 fungal species - Fusarium ambrosia and Fusarium solani.
Mutual Association of Fungi with Ambrosia Beetle
- Ambrosia beetles dig tunnels (called galleries) in tree bark and carry fungal spores with them.
- These fungi grow inside the tunnels. The beetles and their larvae do not eat wood; instead, they feed on the nutrient-rich fungal mycelia growing inside the tunnels.
- The fungi weaken the wood by secreting enzymes, allowing the beetles to go deeper.
How is it a threat to Rubber Plants?
- The fungi travel deep inside the plant, especially through the xylem (the water-carrying tubes of plants), this blocks water flow making the tree dry out and die.
- The infection also affects total latex production from rubber trees causing economic and agricultural losses.
- Controlling the fungal infection is difficult as the Fungi reside in deeper parts of the infected plant, where insecticides or fungicides often do not reach. Once infected, the tree takes a long time to recover or may not survive at all.
A few species of ambrosia beetles, including Euplatypus parallelus, are invasive and threaten horticulture and silviculture worldwide. The infection also makes other economically significant plants such as coffee, cashew, mango, and coconut vulnerable to infections.
Being flying insects, the beetles can access a variety of trees. It can infest more than 80 species of broadleaf trees including cashew, teak, coconut, and coffee. Additionally, it may associate with other pathogenic fungi posing a bigger threat to plantations.
Way Forward
To combat the infection the experts suggest to:
- Sustainable treatments such as using antagonistic fungi to outcompete pathogenic Fusarium species.
- Apply microbial consortia with a diversity of bacterial species that can live inside plants, colonise plant tissues and enhance resistance to fungal infections.
- Remove infected parts of the trees- burn or chip away any part that displays holes.
- Rubber farmers have called for the use of genetically modified (GM) rubber plants.
Also Read: Govt raises funding for development of natural rubber sector