Termite colonies use chemical cues to distinguish queens from workers

Group of termites

Colonies of termites depend upon chemical signals to separate their royal families from mere commoners, according to new research co-authored by a Texas A&M University entomologist.

Ed Vargo, professor and holder of the Endowed Chair in Urban and Structural Entomology, Department of Entomology, College of Agriculture and Life Sciences, is among a team of scientists who recently published “Identification of a Queen and King Recognition Pheromone in the Subterranean Termite Reticulitermes,” in the scientific journal Proceedings of the National Academy of Sciences.

Co-authors with Vargo were Coby Schal, Blanton J. Whitmire Distinguished Professor of Entomology, North Carolina State University; Colin Funaro, doctoral student for Vargo and Schal, North Carolina State University; and Katalin Boroczky, research chemist, Penn State University.

Termites are group of wood-eating insects that serve as important decomposers in nature, but some types are highly destructive pests to human-built structures, Vargo said.

“Regardless of type, all termites live in highly cooperative colonies consisting of different castes, such as the kings and queens, the reproductive caste and the worker or non-reproductive caste,” Vargo said. “It’s long been suspected that termites within a colony can distinguish caste members based on chemical cues, but until now no active chemical compounds had been identified. Our team of biologists and chemists set out to identify those chemical cues that mediate caste recognition.”

To find those chemical cues, called pheromones, the team selected Reticulitermes flavipes, the most widespread North American termite species, to study. They isolated a hydrocarbon, heneicosane, a substance unique to royals, applied it to glass “dummy queens” and were able to duplicate the same behavior in workers to the glass queens as they exhibit to real termite royals.

Vargo said the work represents an important breakthrough, especially when one considers social insects such as honeybees, fire ants and termites are remarkable creatures among which thousands of individuals work together to form a superorganism.

“How these superorganisms function and how they evolved have long been of intense interest to scientists,” he said. “This work helps us understand how termites and other social insect colonies function and offers a window into their evolution.

“Because termites rely heavily on chemical communication to function efficiently, by decoding their chemical language, in the future we may be able to disrupt their activity in a targeted and environmentally friendly way to protect our homes and property.”

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