Some termite species exhibit a remarkable and counterintuitive defense strategy: self-sacrifice through an explosive rupture. This act is a real biological phenomenon. It represents an extreme form of altruism, where individuals give their lives to protect the entire colony. This article explores the mechanics of this unique “explosion” and the science behind this self-sacrifice.
The Phenomenon Explained
When threatened, certain termites engage in a forceful rupture of their own bodies. This is not an explosion in the pyrotechnic sense, but a sudden bursting that releases a defensive substance. The physical act involves the termite contracting its muscles with such force that its body wall breaks open. This rupture occurs at specific points on the termite’s abdomen or back.
Upon rupture, a sticky, often colored, liquid is expelled. This substance can appear as a burst of blue or yellow goo, depending on the species. The expelled material then coats and immobilizes attacking predators, such as ants. The termite performing the act perishes in the process.
The Termites Behind the Blast
Several termite species are known for this self-sacrificial defense, primarily within the genera Neocapritermes and Globitermes. Neocapritermes taracua, found in French Guiana, is a well-studied example. In this species, older worker termites typically carry out this explosive defense. As these workers age, their mandibles, used for foraging and nest maintenance, become worn down, making them less effective at other tasks.
These specialized worker termites possess anatomical features that facilitate their explosive defense. Neocapritermes taracua workers develop distinct pouches or “backpacks” on their backs that contain a blue substance. These pouches accumulate defensive compounds over the termite’s lifetime. Globitermes species, common in Southeast Asia, have soldier termites with large glands occupying a significant portion of their bodies. These glands store a yellow liquid used in defense.
The Science of Self-Sacrifice
The “explosion” in these termites is a chemical reaction. In Neocapritermes taracua, two different chemicals are stored separately within the termite’s body. One component is an enzyme, a blue laccase called BP76, accumulated in external pouches on their backs. The other component consists of relatively benign secretions produced in the termite’s salivary glands, which include hydroquinone precursors.
When attacked, the termite deliberately ruptures its body, causing these two substances to mix. The enzyme and salivary secretions react to create a highly toxic and sticky compound, often described as poisonous benzoquinones. This corrosive mixture immobilizes and can even kill predators. The enzyme’s longevity and stability within the termite’s body are attributed to a protein structure that keeps it active throughout its life.
This self-sacrifice, known as autothysis, is an adaptive strategy benefiting the entire colony. The death of a few individuals protects the larger group, including the reproductive queen and king, and younger, more productive members. This behavior aligns with kin selection, where individuals enhance the survival of shared genes by helping relatives reproduce, even at the cost of their own lives. By sacrificing themselves, older workers contribute to the overall fitness and survival of their colony.