New Delhi : Camouflage has been a nature’s gift that both predators and those preyed upon have relied on in the unforgiving battle for survival. What we have not known is that Insects were already doing something very similar in the Cretaceous period between 145 and 65 million years ago. They cloaked themselves in pieces of plants, grains of sand, or the remains of their prey, in order, for example, to be invisible to predators.
An international research team, with participation from the University of Bonn, has now investigated such "invisibility cloaks" encased in amber. The custom-tailored "costumes" also permit conclusions about the habitat at the time. The results have now been published in the journal "Science Advances".
The larva of the lacewing attacks a pseudoscorpion and uses its powerful mouthparts to suck it dry.
The larva then puts the remains of the dead prey on its back.
The outlines of the lacewing are now unrecognisable. It looks more like a dead pseudoscorpion. This camouflage protects the lacewing against being recognised by predators and at the same makes it easier to hunt its own prey. "With this 'disguise', the lacewing larva pretends to be someone completely different", says Prof Jes Rust of the Steinmann-Institute of the University of Bonn. "Using the pieces of its prey, it even takes on the smell of the pseudoscorpion". The scene plays out in the Cretaceous and is recorded as a "snapshot" in amber.
A research team under Dr Bo Wang of the State Key Laboratory of Palaeobiology and Stratigraphy in Nanjing (China) worked together with palaeontologists from the University of Bonn and other scientists from China, USA, France, and England to examine a total of 35 insects preserved in amber. With the aid of grains of sand, plant residue, wood fibres, dust, or even the lifeless shells of their victims, the larvae achieved camouflage to perfection.The amber samples come from Myanmar, France, and Lebanon. "These are very rare fossils, which give us unique insights into life more than 100 million years ago", says Dr Torsten Wappler of the Steinmann-Institute of the University of Bonn, who joined Dr Wang and Professor Rust to classify these oldest examples of camouflage.
The research team was astonished to see the broad range of camouflage already used by insects in the Cretaceous. Some larvae fashioned a kind of "knight's armour" from grains of sand, perhaps to protect against spider bites. In order to custom-tailor their "camo", they have even adapted their limbs for the purpose. The larvae were able to turn their legs about 180 degrees, in order to transport the grains of sand onto their back. Others cloaked themselves in plant residue, in order to become one with their surroundings, making them almost undetectable to predators. It is very surprising how early in evolution such complex insect behaviour developed: The larvae had to search actively for suitable 'camouflage material', pick it up, and cloak themselves with it", says Dr Wang.