Termites are social insects known for consuming materials indigestible to many other organisms. This unique dietary adaptation allows them to play a role in natural ecosystems, but also makes them a concern in human environments due to the materials they target.
The Core Diet: Cellulose
The fundamental component of a termite’s diet is cellulose, a complex carbohydrate that forms the primary structural material in plant cell walls. Cellulose provides termites with the energy necessary for their survival and colony functioning.
Wood is the most common natural source of cellulose for termites. They consume it in various forms, including structural timber, dead trees, and fallen logs. Different termite species may prefer softwoods like pine, spruce, and redwood due to their lower density and easier digestion. Moist or decaying wood is particularly attractive as it is softer and simpler to consume.
How Termites Process Their Food
Termites break down cellulose, a substance indigestible to most animals, through a symbiotic relationship with microorganisms in their gut. These microbial partners, including protozoa and bacteria, produce specific enzymes that digest cellulose. These enzymes break down cellulose into simpler sugars, which termites then absorb for energy.
Symbiotic Digestion
In lower termites, flagellate protozoa within the hindgut are primarily responsible for cellulose digestion, secreting enzymes like cellulase and cellobiase. These protozoa often host symbiotic bacteria that further contribute to the digestive process. Without these protozoa, lower termites cannot obtain nutrients from their cellulose-rich diet.
Higher termites, a more evolutionarily recent group, have lost these symbiotic protozoa. Instead, they rely on a diverse community of bacteria in their gut to produce the necessary enzymes for cellulose breakdown. Some higher termites, particularly fungus-growing species, can even produce their own cellulose-digesting enzymes.
Beyond Wood: Other Cellulose Sources and Supplementary Diets
While wood is a primary food source, termites also consume a variety of other cellulose-containing materials, particularly those found in human environments. Paper products, such as books, documents, cardboard, and wallpaper, are highly susceptible to termite damage due to their cellulose content. Cotton fabrics and other natural fibers like linen also contain cellulose, making them potential food sources, especially if stored in damp conditions. Termites can even damage the paper backing of drywall, which is rich in cellulose, to access other structural materials.
Beyond cellulose, some termite species utilize supplementary food sources. Fungus-farming termites cultivate symbiotic fungi within their nests, consuming both the fungi and the fecal combs they grow on. The fungi help break down plant material and provide additional nutrients like nitrogen. Certain species may also consume animal waste containing undigested plant material, or opportunistically feed on dead insects or other termites for supplementary nutrients.