Invertebrates
Dead Leaf Mantis
Deroplatys desiccata · also called dead leaf mantis, Malaysian dead leaf mantis
The dead leaf mantis does not hide among dead leaves — it is a dead leaf, or does a good enough impression to fool the birds that would eat it and the flies it eats. Brown, flattened, veined, and edged with fake decay, it hangs in the litter of the Southeast Asian rainforest and sways gently, waiting.
Overview
Dead leaf mantises (Deroplatys desiccata and relatives) live in lowland rainforest across Southeast Asia. They are ambush predators, sitting motionless on the forest floor or in low vegetation and seizing passing insects — and other mantises — with spined forelegs in a strike that lasts a few hundredths of a second.
Being a leaf
The mantis’s disguise is masquerade — imitation of a specific object. The plate behind its head is broadened into a crinkled, leaf-shaped shield with a raised “midrib”; the wings carry vein-like lines and blotches of fake rot; the legs have leaf-lobes; and the resting posture is that of a curled, hanging leaf. Among real dead leaves it simply disappears.
Swaying
As it walks, the mantis rocks its body back and forth, matching the way a dead leaf twitches in the breeze — so even a moving mantis still reads as a leaf. The same motion helps it judge distance to prey by parallax.
When the disguise fails
Discovered, the mantis switches to a startle display: it rears up, flings its wings open to flash hidden eyespots and colours, spreads its spined forelegs, and lunges — trying to look suddenly large and dangerous long enough to escape.
Status
The dead leaf mantis has not been assessed for conservation. It is locally common in intact forest and widely captive-bred for the pet hobby, where it is one of the most popular species.
Dead Leaf Mantis: common questions
How does the dead leaf mantis's camouflage work?
It is masquerade — pretending to be a specific object rather than blending into a background. Almost every part of the mantis contributes — the enlarged plate behind the head (the prothorax) is broadened into a crinkled, leaf-shaped shield with a raised ridge like a leaf's midrib; the folded wings are brown and grey with darker lines that look like veins and irregular patches that look like fungal rot and insect damage; the legs bear leaf-like lobes; and the overall posture is that of a curled, hanging leaf. Sitting motionless among real dead leaves, whether on the forest floor or caught in low vegetation, the mantis is effectively invisible to both the insects it hunts and the birds and lizards that hunt it.
Why does it sway when it moves?
Two reasons. First, camouflage in motion — a dead leaf in the forest is not perfectly still; it twitches and rocks in air currents. By swaying rhythmically as it walks, the mantis matches that expected movement, so a moving mantis still reads as a leaf rather than as an animal. Second, rangefinding — like other mantises, it uses the way nearby and distant objects appear to shift against each other as it moves its head and body (motion parallax) to judge exactly how far away a prey insect is before it strikes. Many mantises "peer" from side to side for this reason.
What does the mantis do if a predator sees through the disguise?
It switches from hiding to bluffing, with a deimatic (startle) display. The mantis suddenly rears its front end up, throws its wings open to expose flash colours and dark eyespot markings that were hidden, raises and spreads its spined raptorial forelegs, and may rock or lunge toward the threat. The aim is to look abruptly much bigger, more colourful, and more dangerous than a leaf, startling the predator into hesitating or backing off long enough for the mantis to escape or strike. If grabbed, it will also bite and slash with the foreleg spines.
Is the dead leaf mantis a good pet?
It is one of the most popular mantises in the invertebrate hobby and is widely captive-bred, which is preferable to buying wild-caught animals. It is considered relatively hardy and forgiving for a mantis — it tolerates a range of humidity, is a robust feeder, and is large enough to handle gently — but it still needs warmth, adequate humidity and ventilation, vertical space to moult, and a steady supply of appropriately sized live insects. As with all mantises, the female may eat the male at breeding time, and both sexes will eat each other at any time, so they are kept individually.