Tag: mantises

South African Mantids Caught Snacking on Snails

Researchers documenting the Polyspilota genus in South Africa have recorded these predators hunting and consuming snails and slugs in the wild for the first time.

While most of us imagine praying mantises as hunters of flying insects, a new study published in the open-access Journal of Orthoptera Research reveals a much slimier side to their diet.

Researchers documenting the Polyspilota genus in South Africa have recorded these predators hunting and consuming snails and slugs in the wild for the first time. This discovery shifts our understanding of mantis ecology from strict insectivores to opportunistic generalists capable of tackling unconventional prey.

*Polyspilota* *aeruginosa* female nymph feeding on common garden snail, *Cornu* *aspersum* in captivity. Photographed by Paul Janse van Rensburg.

Lead researcher Bianca Greyvenstein of North-West University in South Africa explains that this find was a major milestone for her team after a decade of studying these insects:

“We have been doing research on South African Mantodea species for about 10 years, and this was the first instance we noted of a mantis eating snails”.

She notes that the team was very suprised that this behaviour also occurs in the wild and not just in captivity. While they attempted to see if other South African species would follow suit, none of the others showed any interest in snails as a food source.

*Polyspilota* *aeruginosa* nymph feeding on silky tailwagger snail (*Kerkophorus* *inunctus*) in the wild (iGwalagwala Trail, St Lucia, KwaZulu-Natal). Photographed by Terence Bellingan.

The appearance of snail-eating behavior might seem like a new evolutionary trend, but the researchers suspect it is simply something we have missed until now. As Greyvenstein points out:

“Very little information is available on mantis species in general, and especially on those in South Africa”.

She believes the documentation of gastropod predation is more likely a reflection of gaps in research and knowledge rather than a sudden change in behaviour. As scientists dig deeper into these genera, they expect to find even more novel behaviours.

Mantodea Mantid *Polyspilota*, Newlands forest Mantids, Feb 2024. Photographed by Paul Janse van Rensburg.

The study also highlights that Polyspilota aeruginosa (common name: the Flag Mantis) is a remarkably flexible hunter. Beyond mollusks, these mantids have been observed eating geckos, proving they are not picky when a high-protein meal presents itself. Greyvenstein notes:

“Praying mantises in general may have a far more varied diet and behavioural repertoire than many people realise”.

Female *Polyspilota* *aeruginosa* eating a tropical house gecko (Leisure Bay, KwaZulu-Natal). Photographed by Gwenikè Lawrance.

She also emphasises that while people often view them solely as insect predators, observations such as gastropod predation show that there is still much to learn about even familiar animals.

A critical component of this research was the data provided by everyday people using platforms like iNaturalist. These citizen science contributions helped the team map the distribution of mantids and identify their varied prey.

“Exciting discoveries are not limited to remote rainforests or deep oceans. There are fascinating behaviours waiting to be documented in local gardens and natural areas. We have really only begun to scratch the surface of these fascinating creatures”.
Bianca Greyvenstein

Mantodea Mantid *Polyspilota*, Tugela, June 2024. Photographed by Paul Janse van Rensburg.

Original source:

Greyvenstein B, Janse van Rensburg P, Bellingan T, van den Berg J, Jordaens K, Stals R, Midgley J (2026) Snacking on snails: Novel prey and the distributions of Polyspilota praying mantids (Mantodea, Mantidae) in South Africa. Journal of Orthoptera Research 35(2): 251-258. https://doi.org/10.3897/jor.35.187916

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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