Ladies and gentlemen, the award for best invertebrate mimicry goes to Hemeroplanes triptolemus for its masterful imitation of a venomous snake.
Native to the Amazon rainforests, the snake-mimicking caterpillar develops into a rather unimpressive moth of the Sphingidae family, but in its larval stage it incorporates a surprising survival tactic. It needs one, too, since without a good defense system, sphinx moth caterpillars are essentially energy-rich “snacks” presented on a bed of leafy greens to jungle predators.
To avoid that fate, the larva of this moth expands and exposes its underside to mimic a snake’s head with black eyes and even light reflections.
It’s no easy feat, though. The caterpillar begins its defensive maneuver by lunging backward and twisting its body to expose hidden shades of yellow, white, and black on its belly. It then sucks in air through tiny holes on its sides (known as spiracles) and pumps it out the front of its body. Once the segments inflate, the caterpillar truly transforms, having taken the form of a venomous snake with a diamond-shaped “face” and large black eyes.
If the “deadly” (and quite expensive) disguise is not enough to deter a predator, such as a lizard or bird, the caterpillar can also attack like a snake to enhance the effect.
Although deflection (a tactic that involves using eyespots to divert predators’ attention away from the head) is not uncommon among animals, the snake-mimicking caterpillar’s false face is actually located at the same end as its real face.
“Deflection may not be very effective for a caterpillar, as it probably won’t survive if an attacker punctures or tears off some part of its body,” explains eyespot expert Dr. Thomas Hossie. “This defense is to intimidate or scare an attacker, who will run (or fly) away rather than risk a lethal encounter with a snake.”
Interestingly, we also know of a moth that camouflages itself as a snake in its fully developed phase, and for which the price of this type of disguise is also quite high in energetic terms.
But this guy seems to outdo everyone else in the animal kingdom in terms of sporting the best snake costume ever.
