Termites are highly social insects that live in structured communities known as colonies. These colonies function as a single, highly organized society where all individuals work towards the group’s survival and reproduction. The number of termites in a single colony varies tremendously, ranging from just a few hundred individuals to many millions. This wide variation depends primarily on the species of termite and the age and maturity of the colony.
Colony Size by Termite Type
The specific number of termites in a colony is largely determined by the species. Drywood termites live entirely within the wood they consume and form the smallest colonies. A mature drywood colony typically contains only a few hundred up to about 5,000 individuals.
Subterranean termites, which build their nests in the soil, create much larger populations. Native subterranean species commonly establish colonies that range from 50,000 to over one million termites.
The largest colonies belong to the invasive Formosan subterranean termite, sometimes called “super termites” due to their aggressive nature and massive size. An average Formosan colony contains between 350,000 and 2 million workers. Some exceptional, well-established Formosan colonies have been estimated to contain populations exceeding 10 million, with the largest recorded containing an estimated 70 million individuals.
Factors Determining Colony Population
While species sets the potential maximum size, several external and internal variables dictate where a colony falls within that range. The age and maturity of the colony is a significant factor, as newly founded colonies begin with only a few dozen individuals. It typically takes several years, often five to ten, before a subterranean colony reaches its mature size of tens of thousands to millions.
The availability of food is directly correlated with the population a colony can sustain. Termites rely on a constant supply of cellulose, meaning the size and quality of the available wood source limit the number of individuals the colony can support. If resources become depleted, population growth will slow or halt.
Environmental conditions also influence colony size and growth rate. Optimal temperatures and sufficient moisture are necessary for the sustained health of the colony. Subterranean termites require soil moisture for their nests, and warmer geographic regions generally support larger, more active populations.
The Role of the Queen and Colony Growth
The massive numbers seen in mature colonies are achieved through the sustained reproductive capacity of the queen. She is the sole primary reproductive source in a founding colony, partnering with a king to start the new society. The queen undergoes a dramatic physical change, with her abdomen swelling to accommodate immense egg production.
A mature queen can lay thousands of eggs every day, with some species producing up to 30,000 or more eggs daily. This production is sustained by a long lifespan; termite queens can live for 10 to 25 years, ensuring continuous population growth for decades.
In large, established colonies, especially subterranean types, secondary or supplementary reproductives may develop. These individuals accelerate population growth by laying eggs alongside the primary queen. This allows the colony to expand its size and maintain its population more rapidly than a colony relying on the single royal pair.
Population Distribution within the Colony
The total number of termites within a colony is distributed across specialized groups, known as castes, each with a specific function. The vast majority of the population belongs to the worker caste, typically accounting for 90 to 98 percent of the total number. Workers are responsible for all non-reproductive tasks, including foraging for food, building and repairing the nest, and feeding the other castes.
The second caste is the soldiers, which are morphologically specialized for defense, often possessing large heads and mandibles. Soldiers make up a much smaller percentage of the total population, generally ranging from 2 to 10 percent in a mature subterranean colony. Their primary role is to protect the colony from invaders, particularly ants.
The reproductive caste, including the queen, king, and winged swarmers (alates), represents the numerically smallest group. The alates are produced at certain times of the year and leave the parent nest to start new colonies elsewhere. This caste is responsible for the colony’s existence and future expansion through swarming and reproduction.