2020 is the year of many memorable things, not the least of which was a presidential election. Termites choose their leaders, too, though not with mail-in ballots or voting machines.
These wood-eating insects live in colonies ruled by a single king and queen who do all the breeding. When they die, an heir must be found from within the colony’s ranks – but the succession is surprisingly peaceful and orderly. Hardly anyone gets killed!
Drywood termites are primitive termites that live in small colonies of 50 to 100 individuals, all nestled together in a piece of dead wood that serves as both shelter and food. Apart from the royal pair, the colony is made up of workers and soldiers, who are all siblings. The workers are utterly misnamed: they do not do any work.
Unlike some social animals, individual termites are genetically distinct from each other, so there is plenty of potential for conflict. Clonal animals, as well as the more familiar social insects – ants, bees and wasps – tend to be fairly well-disposed towards each other, because preserving each other means preserving their own genes. But termites are different.
What’s more, apart from the soldiers who are sterile, every termite in the nest has the ability to become a breeder. So if the royal pair dies the colony should collapse into violent anarchy, with every worker fighting for itself. This sometimes happens in honeybee colonies when the social order breaks down.
Researchers in Germany wanted to find out how the termites went about resolving the succession question. They collected 17 wild colonies and kept them in wood blocks in their lab where they could monitor them closely. Then they removed the royal pairs and watched how the workers reacted.
Within nine days of the royals leaving, some of the workers moulted and acquired the potential to breed. But only about 12 percent of the workers underwent this transformation: the others stayed as they were. The theory is that when the termites moult, there is a brief period when they can pick up signals from nest-mates and change their status – but because this time is short, only a few become breeders.
The breeders then competed among themselves for the right to reproduce. One element of this was straightforward: they attacked each other until one was wounded, and the injured individual would then be finished off and eaten by workers. Workers always eat injured individuals; it’s a way of recycling valuable nutrients.
But just as importantly, the breeders became much more social, like politicians canvassing for support. They spent a lot of time feeling other individuals with their antennae: workers and breeders have different chemicals in their cuticle, so feeling each other is a way of finding out who is who.
They also spent much more time than usual feeding their “constituents” with surplus food, which they squeezed out of their bottoms. This seemingly generous (but undeniably icky) act may actually be a subtle dominance signal, in effect saying: “Look at me, I am so well-fed and powerful I can afford to pass out food.” There may also be something still more insidious going on: as well as food, the anal secretions might contain hormones or pheromones that stop the recipient from breeding. Within 11 days of the first breeders emerging, the new royal pair is installed.
While we can learn lots of things from termites, maybe succession is not one of them!
Are termites becoming a royal pain in your home? It’s time to contact a pest control professional who can effectively stop the damage.