How Do Stick Insects Respond To The Predators That See Through Their Camouflage?
Phasmids are a particular order of insects that are more commonly known as stick insects. Phasmids comprise an abundance of species located in various regions of the world. Scientists have documented around 3,000 different phasmid species, but more are being found regularly. Phasmids are closely related to crickets, praying mantids, cockroaches and katydids. Most people will recognize an immediate association between the well-camouflaged praying mantid and the cryptic phasmid, as phasmids hide from predators by using their stick-like appearance to blend in with foliage, hence their common name, stick insects. Although phasmids and praying mantids are both blessed with the evolutionary gift of camouflage, praying mantids are carnivorous and predatory while phasmids are herbivores and relatively passive. Considering this difference, phasmids are far more reliant on their natural camouflaged appearance for their survival than praying mantids are. However, this does not necessarily mean that phasmids are doomed to being eaten alive when a predator manages to see through their disguise.
Unfortunately for female phasmid species, only the males are able to use their wings in order to make airborne escapes from predators. When a female phasmid becomes aware that it is being eyed by a predator, it will attempt to perform natural-looking movements in order to escape the predator’s visual contact. For example, a female phasmid may move itself behind an object in a manner that makes it look like a leaf being blown in the wind. If this particular method is not an option, or has failed, then a female phasmid can violently flicker its wings as a show of intimidation to deter predators from attacking. In order to compensate for their inability to make airborne escapes, some female phasmid species can intimidate predators by exposing a colorful stripe located beneath one of their wings. In the insect and spider world, bright colors on insect and spider bodies indicates their toxicity to predators. Although female phasmid species are not toxic to predators, some species have, nevertheless, acquired the colorful stripe as a survival adaptation. This colorful stripe only becomes visible during the female’s defensive display.
Have you ever witnessed the violent defeat of an insect by another smaller insect?