Termites are highly organized social insects living in colonies structured around a distinct caste system, including workers, soldiers, and reproductives. At the center of this complex society is the queen, the sole reproductive female responsible for populating the entire colony. Her physical form is dramatically different from her subjects, undergoing a transformation that results in immense size.
Measuring the Monarch: Size and Caste Comparison
The fully mature termite queen reaches a size disproportionate to all other colony members. While typical worker or soldier termites measure only 4 to 15 millimeters, queens of larger species can be several inches long. Queens of the African genus Macrotermes, for example, commonly reach lengths of 4 to 6 inches (10 to 15 centimeters). This immense size can make her body potentially one hundred times the mass of a single worker termite.
A worker termite is roughly the size of a grain of rice, while the largest queens can be compared to the size and shape of a small sausage. This size difference means the queen is effectively immobile, confined to a specially constructed “royal chamber” deep within the nest. The king, who remains her mate, does not undergo the same dramatic physical enlargement, remaining comparable in size to other castes.
Physogastry: The Process Behind the Queen’s Gigantic Size
The queen’s dramatic size increase is due to physogastry, a biological process translating literally to a “swollen abdomen.” This physical change begins after the queen establishes a new colony and commences her reproductive duties. Physogastry involves the disproportional enlargement of the abdominal cuticle and the internal reproductive organs.
The massive swelling is primarily caused by the hypertrophy of the ovaries and the fat body, an insect organ that stores nutrients. Unlike most insects that grow by molting, the termite queen achieves continuous growth without shedding her exoskeleton. She instead stretches the intersegmental membranes of her abdominal exoskeleton, which results in a pale, taut, and translucent abdomen. This slow, continuous expansion can take several years to fully develop.
The Reproductive Engine: Function and Longevity
The immense size of the termite queen is directly correlated to her function as the colony’s central reproductive engine. Her greatly enlarged abdomen accommodates a vast number of mature ovaries, allowing for an unparalleled oviposition rate. A mature queen of a prolific species can produce between 20,000 and 40,000 eggs every day. For large species like Macrotermes subhyalinus, this rate translates to approximately 30 eggs per minute.
This continuous, high-volume production is the purpose of her specialized morphology, as the queen creates the entire colony population. Workers constantly attend to her, feeding her and carrying the eggs away to the nursery chambers. This unwavering care and protection, combined with a specialized diet, grants the queen an exceptional lifespan. She is one of the longest-living insects, with an average lifespan commonly ranging from 15 to 20 years, and occasionally reaching 30 to 50 years in some African species.