Kill, Fido! Docile ants become aggressive guard dogs after a secret signal from their caterpillar overlord. The idea turns on its head the assumption that the two species exchange favours in an even-handed relationship. The caterpillars of the Japanese oakblue butterfly (Narathura japonica) grow up wrapped inside leaves on oak trees. To protect themselves against predators like spiders and wasps, they attract ant bodyguards, Pristomyrmex punctatus, with…
They look like comfy cushions from the outside, but inside they contain mini-ecosystems, sheltered from the harsh mountain environment around them. One of the best ways for mountain plants to maximise their chances of survival in extremes of wind and temperature is to form a dome shape. Hundreds of species do it, including the two-flower cinquefoil (Potentilla biflora, pictured below). Now it appears that many…
On Costa Rica, inside a wheel of sticky silk, an orb weaver spider is doomed to die. She is a formidable predator, but this Leucauge argyra has fallen victim to something even worse. A white grub is stuck to her abdomen, and it’s growing bigger while the spider shrinks. One day, the spider stops building her usual orb web. Instead, she keeps repeating the first few steps,…