Odontotermes obesus, a species of termite, is known for cultivating fungi, specifically Termitomyces, within their mounds. These termites gather dead leaves, wood, and grass to create underground gardens, referred to as combs, where the fungi decompose tough plant materials, making them more digestible for the termites. This intricate system exemplifies a form of symbiotic agriculture.
However, termites face a significant hurdle in their gardening endeavors: the presence of weeds. Numerous studies have suggested that these insects possess a fixed response when they encounter weed infestations. “But that was not the case,” states Rhitoban Raychoudhury, a biological sciences professor at the Indian Institute of Science Education. In a recent study published in Science, Raychoudhury’s team found that termites employ complex and surprisingly sophisticated gardening techniques.
Challenges of Gardening in the Dark
At first glance, termites may not seem like ideal gardeners due to their effective blindness, which is understandable given they reside primarily in the dark tunnels of their mounds. Yet, termites compensate for their visual limitations through enhanced olfactory and tactile senses. “They can navigate their environment and identify weeds using these advanced senses,” explains Raychoudhury. To investigate termites’ responses to weed infestations, his research team collected samples of Odontotermes obesus and subjected them to various gardening challenges.
The experimental design involved using autoclaved soil from termite mounds placed in glass Petri dishes. Raychoudhury and his colleagues introduced two fungus combs into each dish. One comb served as a control—a fresh, uninfected sample of Termitomyces—ensuring the termites had a reliable food source, as survival outside their mounds can be difficult. The other comb was deliberately contaminated with Pseudoxylaria, a fungal weed known to invade Termitomyces habitats within termite colonies.
