Scientists Discover Female Termites Who Don't Need Males to Reproduce

Some female termites can reproduce without males, researchers have found. Getty Images

Scientists have found female termites in remote, coastal parts of Japan that can reproduce without the need for male mates.

Some glyptotermes nakajimai termites, which populate pieces of dead wood, can produce offspring in the absence of males, according to researchers at University of Sydney and Kyoto University.

The vast majority of species reproduce sexually (commonly known as mating), and both males and females partake in social activities, the authors of the study published in the journal BMC Biology wrote. Even in most termite species, populations of male and female workers and soldiers are the norm, and males are crucial to reproduction.

"Our paper is the first demonstration that termites can do away with males completely by the evolution of an asexual lineage, and get along fine just with females," Dr. Toshihisa Yashiro, of the School of Life and Environmental Sciences at the University of Sydney, told Newsweek.

The team made their discovery by studying mature colonies from ten termite populations in Japan. Insects from 37 female colonies were compared to 37 mixed-sex colonies.

Examining the spermathecae—an organ where sperm is stored—of the queens in the all-female population, the team noticed the sacks were empty but the creatures were reproducing regardless. Instead, females reproduce parthenogenetically: where the embryo grows and develops without being fertilized. In contrast, sperm had collected in the spermathecae of the mix-population queens.

The asexual termites looked different, too. Their soldier populations, which were smaller in number than generally seen in termites, shared the same heads size, indicating they are more efficient, according to the authors. This in turn likely aids their population growth.

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Termites populate wood. Most populations include male and female insects. Getty Images

And as only females are required to reproduce, the quirk of asexuality enables all-female populations to grow at twice the rate of sexual populations, said Yashiro. This spike in the growth rate makes it easier for the termites to entrench themselves in new habitats.

Digging into the evolutionary history of asexual termites, the scientists found a single origin for the insects. They believe the asexaul termites diverged from the sexual population 14 million years ago.

Based on this study, glyptotermes nakajimai join ants and honey bees in the short list of advanced animal societies where males are becoming obsolete when they were once indispensable. In both ants and bees, workers are always female and males do not exhibit any helping behaviors, the authors noted.

So what implications do the sex lives of termites have for the wider animal kingdom?

"The question of why organisms have sex and why they produce males [that cannot reproduce alone] is one of the most enduring puzzles in evolutionary biology," argued Yashiro. "Only a portion of animals can reproduce without males [about 2 percent in insects and far less in vertebrates] and more limited animals have completely lost males. Almost all the asexual animals are not social like termites are [i.e. they don't live in highly specialized colonies].

"Our findings demonstrate that males are not essential for the maintenance of animal societies in which they previously played an active social role, providing important insights into the evolutionary significance of sex and the impact of males on animal societies.

Termites comprise approximately 3,000 species in the world and inhabit ecologically diverse habitats, such as human habitations, deep in the forest, deserts, and remote islands, he continued.

"However, the mating systems and the social structures of almost all termite species are still to be scrutinized. We will uncover their societies, which will provide us findings beyond our imagination," he said.

Dr. Rebecca Rosengaus​, associate professor in the department of marine and environmental sciences at Northeastern University, who was not involved in the study, told Newsweek: "I was surprised that even today, we can find sexually reproducing glyptotermes nakajimai​ and therefore, we are witnessing evolution and divergence in action!"

She praised the study as thorough and well-carried-out. However, she pointed out that further research is required to answer several remaining questions. For instance, are these colonies more susceptible to disease due to the low genetic variability compared with colonies headed by sexually producing kings and queens? And do they embryos taking longer to hatch if they are laid by an asexual mothers?

"Understanding the cost and or benefits of this unique form of reproduction will open up new lines of inquiry. And this is exciting," said Rosengaus.