UF/IFAS examine sheds mild on termite colonies

ABOVE: Nan-Yao Su in front of an underground termite colony in the termite lab at the Fort Lauderdale Research and Education Center. COURTESY OF TYLER JONES UF IFAS

Social insects like ants and termites have changed many of the rules of how scientists understand biology. For centuries, this has led researchers to wonder how such organisms evolved to be so successful.

However, a team of entomologists from the University of Florida at Fort Lauderdale are finally providing a first glimpse into the remarkably long lifespans of several of Formosa’s underground termite colonies.

UF/IFAS scientists learned that each termite colony can try different strategies to optimize their chances of survival and reproductive success.

“Scientists have often observed ant and termite colonies over short periods of time to study intriguing behaviors of these complex social animals,” said Thomas Chouvenc, assistant professor of urban entomology at the UF/IFAS Fort Lauderdale Research and Education Center. “However, no one has been able to trace the demographic history of an entire colony over its entire lifetime, which can span decades.”

Termite Alate of the Asian subterranean termite species. COURTESY OF THOMAS CHOUVENC

In an unprecedented effort initiated in 1986 by distinguished UF/IFAS professor Nan-Yao Su, also in Fort Lauderdale, scientists monitored colonies of Formosa’s subterranean termites on site monthly until the project was canceled in 2009.

“The outcome of this effort led to a treasure trove of information that revealed unknown aspects of the complex biology of a termite colony, and it provided unique explanations for why some subterranean termite species may be so good at being troublesome building pests,” said Mr. Chouvenc said. “With more than 15,000 data points and a dozen different variables from many colonies collected over decades, it took us dozens of independent studies and more than another decade to analyze this dataset and make sense of it.”

For the first time, the researchers observed changes in population structure within four independent termite colonies over an observation period of 10 to 24 years. Scientists have found that a full-fledged termite colony can produce thousands of alates, the winged termites, that fly off to start new colonies each year for several decades.

“Initially we thought that all four colonies would follow similar demographic and reproductive patterns. However, each colony had a unique profile, leading us to conclude that each colony may exhibit a unique demographic individuality,” said Mr. Chouvenc.

The UF/IFAS researchers also found that colonies can lose their original primary king and/or queen, but can produce many secondary reproductive queens and kings to maintain reproductive performance through long inbreeding cycles.

“What was fascinating about these findings was that some colonies failed to produce replacement queens and kings and died after three years of colony aging,” said Mr. Chouvenc. “On the other hand, some colonies have been able to produce more than 1,300 surrogate queens and kings and have been thriving for more than a decade.”

In fact, this dataset showed that each colony’s demographic trajectory is unique because of its persistence, he said. “Now that we know how complex and diverse this is, we can now take this information into account when implementing future pest control solutions.”

The study, published in Frontiers in Ecology and Evolution, showed that a mature Formosan termite colony has many options and strategies to optimize its reproductive performance and can switch from one strategy to another over the decades in order to survive.

Mr Chouvenc also compared the finding to the changes that occur in a large city over time, such as B. the changes in demographic composition, building architecture and economic productivity over a 75 to 100 year history.

“It’s similar with termites, but to a different extent, where the colony undergoes a change of generations every three to four years. A colony’s demographic outcome changes due to changes in reproductive strategies, physiological flexibilities, and environmental changes,” noted Mr. Chouvenc. “In a way, just like our cities, termite colonies are resilient and changing over generations. Just as every town is unique, so every termite colony is unique.” ¦

The mission of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is to develop knowledge relevant to agricultural, human and natural resources and to make that knowledge available to help sustain people’s quality of life and to improve. With more than a dozen research facilities, 67 County Extension Offices, its students and faculty at the UF College of Agricultural and Life Sciences, UF/IFAS brings science-based solutions to the state’s agricultural and natural resource industries and all Florida residents. Visit www.ifas.ufl.edu