Termites have garnered a bad reputation – most of us consider them pests, a status not helped by their reclassification into the cockroach family!
However, did you know that just 3.5% of termite species cause problems for humans (and their buildings), with the remaining 86.5% serving as crucial ecosystem engineers – an all-important actor responsible for maintaining the infrastructure across various environments?
Now, scientists are working to establish the world’s most comprehensive system for termite classification, building on the work of 46 global scientists that will (in time) help distinguish between termites that cause problems and those that are key to ecosystem management.
Published in Nature, Genomic data provide insights into the classification of extant termites and has reclassified more than 3,000 species into a “tree of life” comprising 30 termite families and subfamilies:
“We have resolved the ambiguity of the previous system with a modular and very robust classification of the termite family,” according to Dr Simon Hellemans, lead author and member of the Evolutionary Genomics Unit at the Japanese Okinawa Institute of Science and Technology (OIST).
“With this new dictionary, we have a solid platform from which we can study the diversification of termites and their roles in their ecosystems, as well as accommodate future discoveries.”
While these classifications may seem arbitrary, Dr Hellemans said that improved categorisation allows researchers to limit the scope and improve research results: “If you want to observe anything in nature, you need to define your units of observation.”
Wood Central understands that the new classifications will streamline the family trees for termites, using DNA testing and big data to improve the morphological analysis (where species are assessed based on physical characteristics and common behavioural traits).
“Over time, the subjectivity of morphological analysis has led to a convoluted family tree for termites,” according to a media statement produced by OIST. “Some termites diversify very quickly, meaning that those species have evolved rapidly compared to others.”
As it stands, the relationship between grouped species is categorised based on three groups – namely monophyly, polyphyly and paraphyly:
- A monophyletic group of species share a common ancestor.
- Polyphyletic groups often share common characteristics but not a common ancestor.
- Paraphyly describes groups that include a common ancestor and some, but not all, descendants.
The problem with termites, a monophyletic group within the cockroach family, is that the traditional classifications for termite species have a great deal of paraphyly and polyphyly owing to confusion over evolutionary relationships.
“Thanks to extensive data analysis and new morphological surveys, we managed to eliminate paraphyly and polyphyly in the termite family tree by splitting up the larger subfamilies,” said Dr Hellemans, “and in doing so, we have created a system that can effectively accommodate the discovery of new lineages while preserving historical family and subfamily names.”
Every family and subfamily within the new termite tree of life is monophyletic, clarifying the evolutionary relationships between species and making it significantly easier to include newly discovered or reclassified species.
The new tree also underscores termite diversity, allowing for much greater precision in research and pest control. For example, the Coptotermes gestroi, a destructive pest species of termites, was initially classified in the Rhinotermitidae family along with the non-pest Dolichorhinotermes longilabius due to their morphological similarities.
“However, early phylogenetic studies suggested that these two species might not be closely related, now confirmed through more advanced phylogenetic and morphological surveys, which reclassified C. gestroi into the Heterotermitidae family,” according to a media statement from OIST.
Rewriting the dictionary of life is no simple feat.
Wood Central understands that the work to update the termite tree of life began during a symposium at OIST in 2022, organised by Professor Tom Bourguignon, the head of the Evolutionary Genomics Unit at OIST. Here, the unit proposed a framework for revising the tree of life, including morphological surveys and data analyses powered by a supercomputer.
Phylogenetic revisions of classification systems are often based on a data model that can take weeks for a supercomputer to calculate, and each time an adjustment is made, the processing begins anew.
“Our classification is based on the convergence of 51 models, each of which took around two weeks to compute,” recounts Dr. Hellemans. “This was only possible thanks to Deigo, which allowed us to run the analyses in parallel.” Deigo is the name of the central supercomputing cluster operated by the OIST Core Facilities. It is named after the prefectural flower of Okinawa and is available to all OIST researchers.
“Phylogenetics cannot stand alone,” stresses Dr Hellemans. While the researchers used computational models of DNA markers to ascertain the family’s evolutionary relationship, they do not account for the termites’ habits or roles in their environments. Instead, this knowledge came from human experts who have dedicated their lives to one subset of our world and have an invaluable scientific familiarity with the species they study.
“Even if it was difficult to coordinate a collaborative project of this size, the new termite classification system is greater than the sum of its parts. With this, we have a much stronger framework for studying these important ecosystem engineers,” Dr Hellemans said.
Why Termites pose a risk to timber-based buildings worldwide
According to the United States Environmental Protection Agency, termites cause billions of dollars in structural damage, with property owners spending at least two billion dollars to treat the damage.
In June, Wood Central revealed that a US-based chemical company, Kop-Coat Wood Protection, was behind a new “dual mode” treatment that was helping to improve wood’s protection against termite infestation.
“Though cost-effective and compliant with ‘meeting a standard’ developed decades ago, termites have metamorphosed into a much more aggressive pest,” according to Scott Porter, Kop-Coat’s Asia Pacific Manager. “Single mode-of-action pesticide treatment has allowed a significant attack by aggressive and common termite species worldwide.”
It comes as laboratory and field research conducted by Kop-Coat Wood Protection Products on evolved termite species shows “near complete protection” when dual-mode pesticide combinations are used in wood treatment formulations.
- To find out more about termite-based treatments and protections, click on Wood Central’s special feature.
