Meet the Orchid Mantis. No it’s not a flower

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The praying mantis is one of the most fearsome predators in the animal kingdom. An ambush hunter, the skinny insect waits patiently for the perfect moment to strike with unsuspecting victims at lightning speed – some several times larger than itself. Its green-brown coloration is perfect for camouflaging itself with its surroundings, but a Southeast Asian parent has taken it to a whole new level.

What are orchid mantises?

A female juvenile orchid mantis (Hymenopus coronatus). Photo courtesy of James O’Hanlon.

True to its name, the female orchid mantis (Hymenopus coronatus) has semi-opalescent, heart-shaped hind legs with yellow and whitish-pink colors that resemble delicate petals, while the mantis’ head and thorax resemble the column of an orchid flower. Walking through a Malaysian garden, you might be tricked into thinking that red orchids are carnivorous because flies, butterflies, and all manner of pollinators are caught by the flowers. But it is only this extraordinary insect that works hard. The males, however, which are about half the size of the female, are much duller and sport a greenish-brown color like typical praying mantises.

Orchid mantises can be found in Malaysia, Indonesia, India, Thailand, Vietnam, and southern China. However, these extraordinary predators are rarely encountered in the wild, so there has been no systematic study of their populations and there is little information available on their microhabitat or fine-scale distribution.

Why do orchid mantises look like flowers?

A juvenile orchid mantis. picture by Frupus/flickr/CC BY-NC 2.0.

Although the orchid mantis was first officially described in 1972, we’ve known this incredible master of disguise for over a century. The famous naturalist Alfred Russell Wallace, who came up with the revolutionary idea of ​​evolution by natural selection entirely independently of Charles Darwin, first suggested that the praying mantis’ resemblance to a flowering orchid is an example of a predatory strategy known as “aggressive mimicry”. In his 1989 book Darwinism, Wallace described the orchid mantis:

“A beautiful drawing of this rare insect, Hymenopus bicornis (in the state of an active nymph or chrysalis), was kindly sent to me by Mr. Wood-Mason, Curator of the Indian Museum, Calcutta. A species, very similar to it, inhabits Java, where it is said to resemble a pink orchid. Other Mantidae, of the genus Gongylus, have the anterior part of the thorax dilated and colored either in white, or in pink, or in purple; and they so closely resemble flowers that, according to Mr. Wood-Mason, one of them, having a brilliant violet-blue prothoracic shield, was found at Pegu by a botanist, and was at one time taken by him to a flower.

Ever since Wallace first described this phenomenon, the predatory strategy of the orchid mantis has been taken for granted. Specifically, the insect’s color, shape and attitude conspire to produce a resemblance to an orchid in order to attract prey, tricked into thinking they are flying towards a nectar-rich flower when in reality they are are about to meet their fate.

But it wasn’t until recently that this hypothesis was actually tested, and the results would surely have surprised the great Wallace.

Juvenile Orchid Mantis. Credit: YouTube.

In a 2014 study, behavioral ecologist James O’Hanlon of the University of New England used spectrometry to measure the overall geometric coloration and morphology of female orchid mantids, finding that the insect was not actually considered an orchid distinct red. The researchers found no match between the colors and shape of the Malaysian orchid mantis’ abdomen and leg lobes and flower petals.

Instead, the praying mantis – which, by the way, does not live near actual orchids but rather inside shrubs and gardens – is seen by other insects as an approximation of various flowers. In other words, the orchid mantis does not imitate a particular plant, such as the orchid, to deceive its prey – it is its own flower, which makes it even more amazing.

O’Hanlon also performed experiments which showed that more pollinators were attracted to the orchid mantis than to any of the different flowers they used as controls. The insects were already moving towards the orchid-mantis without the need for camouflage, which showed that in fact the mantid-mantises do not actually employ cryptic mimicry like other insects, such as the leaf-like katydid.

A female juvenile orchid mantis devouring her prey. Photo courtesy of James O’Hanlon.

“Other animals, such as crab spiders and assassin bugs, camouflage themselves in flowers or manipulate floral signals, but the orchid mantis is the only animal that actually takes on the appearance of an entire flower. Rather than “To use real flowers, the flower-like body of the orchid mantis can attract pollinators even away from the flowers. This strategy seems to be remarkably successful; they can attract even more pollinators than real flowers,” says the researcher. wrote.

An adult female orchid mantis. Photo courtesy of James O’Hanlon.

He goes on to explain his reasoning in more detail:

“If you are a flower, you are [often] interested in attracting a specific pollinator, because you want that pollinator to visit other flowers of the same type to transfer your pollen. If you’re a praying mantis, you don’t really want a specific type of insect, you just want something you can eat.

An evolutionary first in insects

In 2016, Gavin Svenson of the Cleveland Museum of Natural History conducted his own survey, measuring the body size of over a hundred orchid mantises with a stereomicroscope in his lab. Svenson and his colleagues also studied the evolutionary relationships between the orchid mantis and its distant relatives by examining how traits, such as color, change and develop over time.

The mathematical model they built suggests that originally an ancestor of the orchid mantis started hanging around the flowers at some point and accessed more food. As these insects reproduced, over the generations, a small group within this lineage began to evolve into larger females, as larger size allows them to take down large and small prey. However, at this stage, these mantids still resembled other species, with a green-black pattern that makes them more difficult for prey and predators to spot.

In the next iteration, the females began to develop their conspicuous yellow, white, and pink colors. However, the males remained small and dull, but this allowed them to be better at hiding and avoiding predators.

“We think males stay small because they have to move around the environment to find females and mate,” said Svenson. “If you look like a conspicuous giant flower and are actively moving, you are betraying yourself.”

Sexual dimorphism, when the two sexes of the same species exhibit different characteristics beyond differences in their sexual organs, is very common in the animal kingdom. Usually these adaptations are for breeding purposes. But this is the first time scientists have found a female adaptation in a species for predatory rather than reproductive purposes. And that would never have been possible without systematic field research, which can help reveal patterns of evolution that we would otherwise not have noticed.

“People ask why studying evolutionary relationships or getting accurate classifications of species is valuable, and this experiment is an example of a good answer,” Svenson said. National geographic.

“Once you know the real lineages, you can do some interesting research that gives you a unique perspective on how evolution works and how things change.”

There’s a lot more to the orchid mantis than meets the eye. Once again, nature is proving surprising and teaching us that we cannot always predict what animals are doing just by their appearance.

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