Keep calm and carry on building. That’s the motto of 100,000 or so wood ants stranded without food in a nuclear bunker until they starve.
Wood ants (Formica polyctena) typically build a cosy mound nest on the forest floor. They seek out the sugary secretions of aphids living on trees and supplement their diet with insects. Now, scientists have uncovered a population of wood ants that has sustained for years without food and light inside a bunker where temperatures are constantly low.
The ant population was discovered in 2013 by a group of volunteers counting bats overwintering in the bunker, which is part of an abandoned Soviet nuclear base near Templewo in western Poland.
Later, Wojciech Czechowski at the Museum and Institute of Zoology in Warsaw, Poland, and his colleagues, entered the bunker to study the ants more closely. They noticed that the wood ants had built a nest on the terracotta floor of the bunker – right below a ventilation pipe. Looking up through the five-metre-long pipe, they realised where the bunker ants come from.
The metalmark butterfly cooperates with ants when it’s a caterpillar, only to stab them in the back when it has metamorphosed into a beautiful – thieving – butterfly.
While still a caterpillar, the metalmark butterfly wins over local ants, including those of the species Ectatomma tuberculatum, with gifts of sugary secretions. In return, the ants, which could easily eat the caterpillar or its adult butterfly form, defend the vulnerable caterpillars from other predators.
But this friendly give-and-take doesn’t last forever, work by Phillip Torres of Rice University in Houston, Texas and Aaron Pomerantz of the University of Florida, Gainesville, has now revealed. When the caterpillars have become butterflies, they turn on their protectors, plundering the source of their nectar.
This nectar is produced by organs called nectaries at the tips of new bamboo shoots, which are tended by ants. Using their mouthparts, they improve the flow from these nectaries, and stop them from running dry. The nectar is an important source of food for them, so they defend these nectaries fiercely.
This ant weaves a nest out of tree leaves high up in the canopy. To build one, a group of workers forms live ant bridges to bring the leaves together, while another fetches larvae from an existing ant nest.
Worker ants hold these larvae in their jaws and squeeze them while moving along the leaf edges. On squeezing, the weaver ant larva produces a fine silk fibre that glues the leaves. As more and more leaves are pulled along, a lump of fresh green leaves lined with a white silk mat is formed.
Study explains how wandering ants guide a group of food gatherers back to the nest.
When out of their nest, workers of the longhorn crazy ant (Paratrechina longicornis) band together toward a common goal: to bring food back to the nest. But even when a few of these long-legged, silver-haired ants (of Ant-Man fame) team up to carry a large item—such as a wasp—they often lose their way home.
A pair of phorid flies hovers over a wounded ant. While the male hangs back, the female lands and walks around the ant, examining it and poking it. Then she hops onto it and rips its head off. Finally, the female drags her trophy across the forest floor to an isolated, safe place, and eats it.
This never-before-seen behaviour is performed by an insect called Dohrniphora longirostrata. It belongs to a group of insects called phorid flies or scuttle flies, or sometimes “coffin flies”.
Several phorid flies have been nicknamed “ant-decapitating” flies because they, well, decapitate ants. But in every known case, the decapitation was incidental. For instance, fire ant decapitating flies lay eggs inside healthy fire ants. When the larvae hatch, they head straight for the ant’s head and feast on its contents. Eventually the head pops off the ant’s body, which is left behind twitching like a zombie.
D. longirostrata is the first phorid fly known to actively cut off an ant’s head before eating it. The discovery has been published in Biodiversity Data Journal.