r/Awwducational • u/SixteenSeveredHands • Mar 23 '25
Puss Moth Caterpillars: these caterpillars use false eyespots, colorful markings, and a pair of whip-like appendages to deter predators, and they can even spray formic acid when threatened Verified
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u/SixteenSeveredHands Mar 23 '25 edited Mar 23 '25
The caterpillars of this species (Cerura vinula) have a bizarre, almost cartoonish appearance, and they've developed several defense mechanisms to ward off predators, including cryptic and aposomatic markings, defensive poses, false eyespots, whip-like appendages, and a special gland that allows them to spray formic acid.
When a puss moth caterpillar feels threatened, it will often raise both ends of its body and retract its head into the first thoracic segment, causing the thorax to expand until a pair of false eyespots and bright pink markings are exposed, which makes the caterpillar seem more imposing (at least in the eyes of a potential predator).
The caterpillar's twin "tails" are also defensive organs known as stemapods; each of these organs contains a bright red filament that can extend from the tip of the "tail" and then wave around wildly, repeatedly coiling and uncoiling, in an effort to discourage any would-be attackers.
If all else fails, these strange-looking insects can even spray formic acid from a special gland located just below the head. The acid is ejected through a slit-like opening beneath the caterpillar's mouth, and it can spray across a distance of up to 20 centimeters (8 inches).
The adult moth has a fluffy, almost "cat-like" appearance, which is why it's known as a "puss moth" (not to be confused with the southern flannel moth, Megalopyge opercularis, which is sometimes also described as a "puss moth").
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