Termites are the unloved outcasts of the social insect world, says Lucy Cooke. Whereas bees are praised for their pollination skills and ants are lauded for their industry, termites are an affront to human civilization, chomping their way through everything we hold dear: our books, our homes and even our cash. In 2011 an errant gang of termites burrowed into an Indian bank and ate $220,000 in banknotes.
Termites are the original anti-capitalist anarchists and, frankly, deserve respect. These blind relatives of the cockroach have been doing astonishing things since the time of the dinosaurs, from maintaining complex societies with divisions of labour to constructing vast skyscrapers complete with air conditioning. Now we can add overthrowing the patriarchy to the list.
In 2018, Dr Toshihisa Yashiro of Kyoto University reported finding the first all-female termite society. Yashiro’s finding is remarkable because, unlike other social insects such as ants and honeybees, termite colonies are usually created by both a queen and a king, which reproduce sexually to produce male and female offspring.
In species like Macrotermes bellicosus, the queen swells into a monstrous egg-laying machine whose abdomen has swollen over a thousand times into a giant, waxy off-white sausage around 10cm long.
- How is a queen bee chosen? And how are they different from worker bees?
- Naked mole rat: what they are and how the queen rules the colony
Her head, thorax and legs remain tiny and can only flail about pathetically, since all other movement is restrained by her grotesque, pulsating girth. She must be fed and her gargantuan maggot-like body cleaned by a legion of workers, allowing her to spend every bit of her energy squeezing out a fresh egg every few seconds, all day every day, for up to 20 years.
At more than 20,000 eggs a day, she’s capable, in theory, of producing some 146 million termites in her lifetime, making her the planet’s most reproductively successful terrestrial animal.
In these traditional mixed-sex mounds, both sexes are thought to play vital roles in maintaining their complex society. So, the loss of males would therefore be genetically and socially significant.
In Japan, Yashiro’s team collected 74 mature colonies of Glyptotermes nakajimai from 15 sites. Thirty-seven of the colonies were exclusively female, while the rest were mixed-sex. The all-female colonies had an extra chromosome compared with the sexual ones, suggesting the two groups may be diverging into different species, having originally split some 14 million years ago.
Their social make-up was also different. In the sexual colonies, a king and a queen produce male and female workers that perform various roles, from nursemaid to armed guard and, later in life, often go on to reproduce themselves. The unisexual colonies are ruled by several cooperating queens. They also have fewer soldiers, leading Yashiro to presume that the all-female army might be more efficient than the mixed one.
In a previous study, Yashiro discovered female termites controlling the switch to asexual reproduction by literally ‘closing the sperm gates’ and sealing up the sperm storage organs (spermathecae) in their abdomens so that males could no longer physically inseminate them. These queens went on to produce genetically identical daughters by cloning instead.
It’s possible that Glyptotermes also actively signed the death warrant of their males by shutting out their sperm from their spermathecae. This decidedly sci-fi scenario is unlikely to be under the queen’s conscious control but, nevertheless, Yashiro concludes that his revolutionary, all-female termite society is the first to provide evidence that “males are dispensable in advanced animal societies in which they previously played an active social role”.