Termites are widely known for their ability to consume wood, a characteristic that makes them significant pests to human structures. While termites are attracted to plant matter, their diet is highly specific, almost exclusively targeting the complex carbohydrate called cellulose. Generally, termites do not eat the fresh, living leaves on plants. Their feeding habits are centered on the breakdown of dead or decaying materials that contain this vital nutrient.
Why Termites Avoid Live Plant Foliage
Termites primarily seek out cellulose, a major component of plant cell walls that provides them with energy. However, the cellulose in a fresh, green leaf is protected, making it an inefficient food source for most termite species. Live foliage contains a high percentage of water, often exceeding 70%, which interferes with the optimal digestive environment required by the insect’s gut microbes.
Fresh leaves also contain various defensive compounds, such as tannins and resins, that are designed to deter herbivores. These compounds can be toxic or make the plant material unpalatable and difficult to process. Furthermore, the cellulose in living plant tissues is often shielded by lignin, a tough polymer that makes the cell wall rigid and highly resistant to enzymatic breakdown.
Termites are instead attracted to plant material that has already begun to decay, a process where fungi and microbes have started to break down these defensive barriers. This pre-digestion lowers the water content and concentrates the available cellulose, making it easier for the termites to access and convert into usable energy.
Diverse Dietary Preferences of Termite Groups
The specific type of cellulose material a termite consumes depends heavily on its species and habitat. Subterranean termites, which are among the most destructive, require contact with the soil and thrive on moist or decaying wood. They often consume the softer spring growth fibers within lumber, leaving the harder summerwood behind.
Drywood termites form colonies entirely within the wood they infest, targeting dry structural timbers, furniture, and hardwood floors. They obtain necessary moisture directly from the wood and do not need soil contact. Dampwood termites prefer wood with a high moisture content, such as decaying logs and stumps, and rarely infest intact buildings.
Beyond wood, termites consume nearly any accessible material that contains cellulose, including:
- Paper products
- Cardboard
- Cotton fabrics
- Accumulations of dead plants
Grass-eating termites feed on both dry and fresh grasses, while soil-feeding termites consume organic matter found directly in the soil.
The Biological Requirement for Digestion
The strict dietary reliance on cellulose is dictated by the termite’s unique digestive system, which is incapable of producing the necessary enzymes. To break down the tough cellulose polymer, termites rely on a mutualistic relationship with specialized microorganisms living in their hindgut. This microbial community includes protozoa, bacteria, and archaea.
These symbiotic organisms produce cellulase, the enzyme required to depolymerize cellulose and hemicellulose into simple sugars. The microbes then ferment these sugars, producing short-chain fatty acids, such as acetate, which the termite host absorbs as its main source of energy and carbon. Without this specialized microbial community, the termite would be unable to extract any nutritional value from wood.