Some Ant Larvae Rule the Colony

“Baby” ants don’t look like much, just little white comma-shaped, headless, legless blobs. But like the young of pretty much any species, they are in charge.

Since ants have complete meta-morphosis, eggs hatch into larvae which, once fully developed, pupate to become adult ants. Biologists have pretty much assumed that the helpless larvae are just there to be fed and cared for and don’t really interact with others in the colony. Eva Schultner of the University of Regensburg in Germany has proven otherwise by studying the role of immatures in the colony structure of various ant species.

The ant colony revolves around the queen, whose sole function is to lay eggs to make more little ants. That takes protein, so workers are constantly foraging to feed their queen. Larvae help in feeding the queen, indirectly, by feeding the workers who feed the queen. Larvae of many species are fed insects that they digest and regurgitate into the mouths of adult workers as a protein-rich liquid. The workers, in turn, feed this gruel to the queen. This food-sharing behavior is in the best interests of the larvae since in times of food shortages, the larvae themselves may be killed and fed to the queen. In the same cannibalistic vein, when their centipede food sources are not available, Amblyopone silvestrii workers will puncture a larva’s skin and drink its blood. Others squeeze a larva’s neck to extract saliva. Solenopsis ants have been known to pinch a larva’s rear end to receive nutrient-rich anal droplets. Ant larvae are no angels; they sometimes cannibalize each other, but they eat only distant cousins. Eating those not closely related helps their more immediate family take over the colony. In some species, larvae appear to eat the newly-laid eggs of an invading queen.

Since a queen needs protein to produce eggs, it follows that in colonies where larvae provide regurgitated food for the queen, the more larvae, the more eggs produced. Here’s where the larvae are in charge. Some, such as Pharaoh ants, have control over the reproductive success of the colony by deciding who gets their regurgitated nutrients. They will readily feed mature queens that have mated (pheromones probably give them away) but withhold from virgin queens who may or may not produce eggs in the future.

How the larvae differentiate individuals for feeding or eating is still a mystery since they don’t have antennae to detect pheromones as do adult ants. (Source: Baby ants have a host of unexpected superpowers. Sandrine Ceurstemont, BBC.com, April 6, 2017)

The authors are well-known industry consultants and co-owners of Pinto & Associates.