First, what is leaf rust, or la roya in Spanish? It is a product of the fungus Hemileia Vastatrix. This airborne fungal disease infects individual leaves of the coffee plant. It is visible on them thanks to the very noticeable discoloration.
However, in the even worse cases the leaves will be unable to photosynthesize. This will make the tree unable to create energy. As a result the plants branches become bare of leaves and coffee cherries alike. This then leads to dwindling harvests for farmers and less coffee to sell and due to the fact that coffee trees take 3-5 years to start producing cherries. This means cutting down these infected trees isn’t always an option for most farmers.
The disease can be devastating to most small-scale farmers in an infected area as the lack of income can result in high poverty levels which can then lead to not even being able to afford the proper prevention techniques to attempt to stop the “rust” from spreading.
This modern strike of leaf rust has been a blight for coffee farmers for nearly a decade now but a study conducted by the University of Michigan revealed a promising lead that could help quicken the pace of the search for a cure to the disease.
This newfound lead is none other than the Bradybaena similaris. The Bradybaena similaris, more commonly known as the Asian Trampsnail, has shown to have been able to shift its diet from plants to the fungal pathogen that causes coffee leaf rust. While this may seem like the perfect solution, it can have many disastrous side effects of biological control of pests. Especially since the snail is already considered an invasive species.
The discovery could however, lead to the uncovering of a different organism in the gastropod family. One that will hopefully be safe enough to use as a weapon against the ongoing threat of coffee leaf rust!