The Orchid Mantis Looks Like a Flower, 'Stings' Like a Bee

The orchid mantis (Hymenopus coronatus) lives in the rainforests of Southeast Asia. It has become popular with insect breeders in the pet trade thanks to its striking looks. The females are big, measuring 2.3 to 2.7 inches (6 to 7 cm) long; their male counterparts average only 0.7 to 1.1 inches (2 to 3 cm) long.

Both closely resemble flowers that are found in their natural environments, like the pink orchid. Since their discovery more than 100 years ago, it was thought these floral mantises evolved to their beautiful pink and white colors and wide flat legs to imitate orchid blooms and confuse other animals.

Then, they would ambush foraging butterflies, moths, beetles, or even frogs and scorpions.

Camouflage in the Animal Kingdom

This type of evolution is called "cryptic mimicry" or "cryptic coloration" and can be used for defensive or aggressive purposes. Other insects, such as the leaf-life katydid, do it too.

It makes sense, right? That's what scientists thought until a few years ago a group of researchers decided to put that hypothesis to the test.

In 2014, scientists did systematic field testing to see how adult female orchid mantises operated. Turns out, they don't use camouflage at all. In fact, insects were attracted to the orchid mantises more than any flower petals. The insects were already beelining toward them without the need for camouflage.

If not cryptic mimicry, why did the orchid mantis behavior evolve this way?

Why Do These Mantises Look Like Orchid Flowers?

By evolving to be larger and more flower-like, female mantises increase their chances to catch insect prey. It's called aggressive mimicry. They don't look like one flower. Research shows that their color evolved to imitate several species of flowers.

James Gilbert, an insect evolutionary biologist, explained it to The Conversation. From an insect's perspective, the color from a distance says to its brain "delicious nectar here." As the insect approaches the orchid mantis, the petal-shaped legs confirm what the insect thinks to be true: It's a flower.

Insects don't have developed brains like ours; their lives are short and they have no critical thinking skills. So naturally, the insect gets trapped and eaten, and the circle of life continues — for the orchid mantis, at least.

Why is this so cool to scientists? A 2016 study led by Gavin Svenson of the Cleveland Museum of Natural History (CMNH) says it's important for a few reasons.

Understanding Behavior of Female Orchid Mantises

First, it's one of the first times that a female adaptation in a species has been for predatory purposes, not reproductive ones. Sexual dimorphism is when a male and female of the same species evolve differently. Usually, the adaptations are both for reproductive purposes.

In the case of adult female orchid mantises, they adapted because they were hungry, not to improve their chances of having babies. Their male counterparts are smaller and camouflage to avoid being eaten, thus increasing their chances of mating. Male orchid mantises catch small and weak prey like fruit flies, grubs and other insect larvae, while the females are able to hunt larger pollinating insects.

Second, this type of study highlights how systematic field research can help reveal patterns in evolution we haven't noticed previously.

Svenson's study wasn't looking at orchid mantis evolution specifically. But after he and his team noticed patterns in their data, they began thinking maybe there was more to the story. CMNH reports that for scientists like Svenson, this kind of discovery is the "holy grail" of systematic research.

And finally, the orchid mantis is the first animal known to mimic an entire flower (color, petals, etc.) — not just part of it — to attract insects of its own accord.