praying mantises

Are people swapping their cats and goldfish for praying mantises?

The first overview of the pet mantis market’s dynamics reports a lack of regulations, but also the potential of a stronger collaboration between hobbyists and scientists for biodiversity conservation.

New research sheds light on the pet insect market and its implications on biodiversity conservation

Rearing insects at home as pets may sound strange, but thousands of people all over the world have already swapped their hamsters for praying mantises or stick insects.

These insects, sold at fairs and pet markets, or collected in the wild and then reared by amateurs or professionals, are gaining increased popularity and fueling a largely unknown market. Not all of them are small, crawling monsters. Some are elegant, with flower-like coloration (the Orchid Mantis, Hymenopus coronatus), and some are funny-looking like Pokémon (e.g. the Jeweled Flower Mantis, Creobroter wahlbergii). Many can be safely manipulated and cuddled as they look at you with big, cute kitty-eyes (the Giant Shield Mantis Rhombodera basalis).

The beautiful orchid mantis Hymenopus coronatus, one of the most priced and requested mantis species on the market. *Photo by* William Di Pietro

When choosing a pet insect, “customers” consider things such as shape, size, colors, and behaviors. They might also take into account how rare a certain species is, or how easy it is to look after. Looking at these preferences, Roberto Battiston of Museo di Archeologia e Scienze Naturali G. Zannato (Italy), William di Pietro of the World Biodiversity Association (Italy) and entomologist Kris Anderson (USA) published the first overview of the mantis pet market. Understanding how this market, which still mostly unregulated, is changing, may be crucial to the conservation of rare species and promoting awareness of their habitat and place in the ecosystem.

A survey among almost 200 hobbyists, enthusiasts and professional sellers in the mantis community from 28 different countries showed that the targets of this market are indeed predictable. The typical mantis breeder or enthusiast, the study found, is 19 to 30 years old and buys mantises mostly out of personal curiosity or scientific interest. Willing to spend over $30 for a single individual, most people prefer beautiful looking species over rare ones.

A cute nymph of the Jeweled Flower Mantis *Creobroter wahlbergii* resting on the tip of a finger. Photo by William Di Pietro

The research, published in the open-access Journal of Orthoptera Research, identified buyers as “mostly curious enthusiasts with poor knowledge of the market dynamics and the laws behind it, even if they seem to generally care about their pet.”

But the data also suggests the trade might not always be on the legal side, as “about one time out of four the lack of permits or transparency from the seller is perceived from the buyer.”

A good collaboration between science and this large community may play a crucial role in the conservation of mantises in nature, the researchers point out.

The Giant Shield Mantis *Rhombodera basalis* looking for a friend. *Photo by* William Di Pietro

Mantises and, in general, insects, are poorly known in terms of biology, distribution, and threats, with many species still unknown and waiting to be discovered. This is a major limit to their protection and conservation, since you cannot protect what you don’t know.

“Hobbyists and pet insect enthusiasts are producing and sharing a huge quantity of observations on the biology and ecology of hundreds of species, even rare or still undescribed ones, a priceless heritage for the scientific community,” the researchers conclude.

“Strengthening the dialogue between them, promoting a white market over a black one, may be a crucial help for the conservation of these insects, fundamental parts of the biodiversity of our planet, that are replacing our traditional pets at home.”

Research article:

Battiston R, Di Pietro W, Anderson K (2022) The pet mantis market: a first overview on the praying mantis international trade (Insecta, Mantodea). Journal of Orthoptera Research 31(1): 63-68. https://doi.org/10.3897/jor.31.71458

Dating in a jungle: Female praying mantises jut out weird pheromone gland to attract mates

Scientists from the Ruhr-University and the Bavarian State Collection of Zoology discovered that females of a South American species protrude a Y-shaped organ on their backs to release pheromones and attract males. Found in none of the over 2,500 species of praying mantises worldwide, the behaviour is reported for the first time in the peer-reviewed scientific Journal of Orthoptera Research.

Female of *Stenophylla lobivertex* with protruded pheromone gland
(Photo by Christian J. Schwarz)

It isn’t only myriads of currently unknown species that await discovery in the Amazon rainforests. As a new study by German scientists at the Ruhr-University (Bochum) and the Bavarian State Collection of Zoology (Munich), published in the open-access peer-reviewed scientific Journal of Orthoptera Research, concludes, it seems that so do plenty of unusual behaviours.

“When I saw the maggot-like structures peeking out from the back of the praying mantis and then withdrew, I immediately thought of parasites that eat the animal from the inside, because that is not really uncommon in insects,”
says Frank Glaw, a reptile and amphibian expert from the Bavarian State Collection of Zoology, who discovered the unusual phenomenon.

How does the Alien Mantis (Stenophylla lobivertex) attract partners?

However, it took specialists in this particular animal group to solve the riddle. Although the experts had seen nothing like this in praying mantises before either, they pointed out that there are other species of mantises, in which mostly unfertilised females release pheromones from a gland in the same part of the body (between the 6th and 7th tergite), in order to attract mates. The Y-shaped organ, which can stretch up to 6 mm in length, is in fact an advanced pheromone gland, which the insect controls with the help of hemolymph.

“We suspect that Stenophylla lobivertex can release the pheromones with the protrusible organ more efficiently and in a more targeted manner than other praying mantises,”
says Christian J. Schwarz, entomologist at the Ruhr-University.

“This can be very important, especially for rare species with a low population density, so that males can reliably find their females.”

Stenophylla lobivertex is a very rare species and lives hidden in the Amazon rainforests. Discovered only 20 years ago, the bizarre-looking and well-camouflaged animal has only been spotted a few times, and apparently only mates at night in the darkness.

*Stenophylla lobivertex* is a rare praying mantis from the Amazon rainforest. Its ‘true’ face becomes apparent only at second glance
(Photo by Christian J. Schwarz)

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Publication:

Schwarz CJ, Glaw F (2021) The luring mantid: Protrusible pheromone glands in Stenophylla lobivertex (Mantodea: Acanthopidae). Journal of Orthoptera Research 30(1): 39-41. https://doi.org/10.3897/jor.30.55274

Two fish a day keep the mantid coming back to prey: The 1st fishing praying mantis

Commonly known to predate on insects, praying mantises have occasionally been observed to feed on vertebrates, including small birds, lizards, frogs, newts, mice, snakes and turtles. Mostly, such records have either not been scientifically validated or have occurred under induced and human-manipulated circumstances.

Nevertheless, no scientific data of mantises preying on fish existed until the recent study of Roberto Battiston, Musei del Canal di Brenta, Rajesh Puttaswamaiah, Bat Conservation India Trust, and Nayak Manjunath, published in the open access Journal of Orthoptera Research.

Last year, the team observed an adult male hunting and devouring guppies in a pond located in a private roof garden in Karnataka, India. Curiously enough, the predator came back five days in a row and caught a total of nine fish (a minimum of two a day). To reach its prey, the insect would walk on the leaves of water lilies and water cabbage growing on the surface of the pond.

*The artificial pond with the praying mantis sitting on a leaf visible to the right.*

Apart from being a curious first-of-its-kind, the observation raises three new discussion points worthy of further study, point out the researchers.

Firstly, the fact that praying mantises hunt on vertebrates outside cages in labs confirms that a single invertebrate species is indeed capable of having an impact on a whole ecosystem. In this case, a mantis preys on guppies which, in their turn, feed on aquatic insects.

*The mantis eating a guppy starting from the tail, while the fish is still alive and breathing in the water.*

Secondly, the discovery questions previous knowledge about the visual abilities of mantises. While the structure of their eyes clearly indicates that they have evolved to prey in daylight, the studied male specimen proved to be an excellent hunter in the dark. The insect managed to catch all nine fish either at sunset or late at night.

Besides visual, mantises might have evolved impressive learning abilities too. The researchers speculate that the observed repetitive behaviour might have been the result of personal experience, utilised to navigate the specimen. Sophisticated cognitive skills, on the other hand, might have allowed the mantis to develop its hunting strategies.

“Remembering the prey’s abundance in a particular site, in relation to their ease of capture and their nutritional content, could be one important factor of this choice and indirectly influence the individual predator’s fitness,” comment the scientists. “This should be investigated in further studies.”

Original source:

Battiston R, Puttaswamaiah R, Manjunath N (2018) The fishing mantid: predation on fish as a new adaptive strategy for praying mantids (Insecta: Mantodea). Journal of Orthoptera Research27(2): 155-158. https://doi.org/10.3897/jor.27.28067

Gender dictates camouflage strategy in this newly identified praying mantis group

Adult females and males in a newly identified genus of Latin American praying mantises have evolved sharply different camouflage strategies, according to a Cleveland Museum of Natural History-led study published in the journal ZooKeys.

Adult males of the new genus retain the stubby, stick-like body configuration and brown coloration they have used as nymphs, whereas adult females, whose bodies grow to be considerably larger to maximize egg production, transform their appearance to mimic a leaf. They change to green, while their forewings become larger and more rounded compared to the male’s, with veins that simulate a leaf structure.

Although adult females are nearly two inches long, the members of this new mantis genus had escaped scientific recognition until recently, in part because the disparity in camouflage tactics made classification difficult.

This shrewdness inspired the name for the new mantis species: Hondurantemna chespiritoi. The genus name (Hondurantemna) derives from Honduras, where the first female specimen was found, in combination with Antemna, a Neotropical mantis to which the new lineage is closely related.

Meanwhile, the species name, chespiritoi, is a nod to the late Mexican comedian Roberto Gómez Bolaños, known as Chespirito, or Little Shakespeare. One of Bolaños’ TV characters, a goofy superhero called the Red Grasshopper, was fond of saying “¡No contaban con mi astucia!” — Spanish for “They didn’t count on my cleverness!” — when he defeated bad guys.

“I grew up watching that TV show in Brazil”, says the study’s lead author, Cleveland Museum of Natural History entomologist and Case Western Reserve University biology Ph.D. candidate Henrique Rodrigues.

“The first male specimen of the new mantis species was from Mexico, like Bolaños,” he explains. “And the signature line of Bolaños’ Red Grasshopper character kind of reminded me of the fact that you had this pretty large species of praying mantis that no one had found for many years.”

Adult female and male specimens of the mantis species were in separate museum collections in Paris, France and San Francisco, California, but had remained unidentified and their relationship unrecognized for more than two decades because of their dissimilar appearances.

Entomologist Julio Rivera, Ph.D., spotted the large green female mantis in the Muséum national d’Histoire naturelle, Paris and brought it to the attention of Cleveland Museum of Natural History Curator of Invertebrate Zoology Gavin Svenson, Ph.D., an international expert on praying mantises. Dr. Svenson later saw the small brown male mantis in the California Academy of Sciences and noted that the two insects, though dissimilar in color and size, had body features that hinted they might be members of the same Antemninae sub-family.

Yet, adaptation to similar environments can cause unrelated organisms to develop similar features. This phenomenon, called convergent evolution, can complicate the process of sorting out connections on the praying mantis family tree.

Dr. Svenson is leading a research project to more accurately reclassify the massive praying mantis family tree using DNA testing and insights from the insects’ body form and features – their morphology. He has consolidated many of the country’s major mantis collections at the Cleveland museum, thus building the Western Hemisphere’s largest assemblage of the insects to aid this effort.

The final pieces of the puzzle that allowed the Cleveland researchers to identify the new mantis lineage arrived by chance. Neil Reid, Ph.D., a lecturer at Queen’s University in Belfast, Northern Ireland, contacted Dr. Svenson, wondering if he wanted to examine a group of unknown praying mantises that Dr. Reid had gathered in a Honduran cloud forest.

The specimens Dr. Reid provided included two adult females and some male and female nymphs in various stages of development. The adult females looked the same as the female from the Paris museum. The male nymphs closely resembled the adult male from San Francisco. Having the nymphs let the researchers see the separate camouflage strategies the male and female mantises adopted as they matured.

Rodrigues conducted DNA tests that confirmed the mantises all represented the same genus and species, which had not been recognized before. The analysis also showed where this new mantis group, or taxon, fit on the complex mantis family tree: verifying that it belonged in the Antemninae subfamily.

“The recognition of H. chespiritoi shows the important role genetics can play in classifying insect relationships. It also highlights the value of museum collections,” Dr. Svenson says.

“When people ask us, ‘Why do you collect things?’, it’s because we still have a shockingly small concept of the biodiversity that’s out there,” Dr. Svenson says. “Museums are the places that hold that biological knowledge, and we’re pulling information out of them all the time.”

Original Source

Rodrigues HR, Rivera J, Reid N, Svenson GJ (2017) An elusive Neotropical giant, Hondurantemna chespiritoi gen. n. & sp. n. (Antemninae, Mantidae): a new lineage of mantises exhibiting an ontogenetic change in cryptic strategy. ZooKeys 680: 73-104. https://doi.org/10.3897/zookeys.680.11162