HIDING IN PLAIN VIEW

In 1942, Donald A. Wollheim wrote a short story called “Mimic,” about a horrifying insect that looked like a man and preyed on transients. Wollheim was a good enough science fiction author to know that six-foot insects are not the most likely creatures, and he had no interest in presenting readers with just another run-of-the-mill BEM. The thrust of his story was that there are more strange and wonderful or horrifying things in the world, hiding in plain view, than scientists could ever hope to catalogue, and that new animals and phenomena would always be discovered, sometimes where we least expected them.

The SF readers of the day agreed enthusiastically, and made the story one of Wollheim’s most lasting works, anthologized repeatedly over the years and liberally adapted into a rather humdrum creature feature in the Nineties. Many scientists, however, turned up their noses at the very idea of any new kind of insect ever coming to light. The insect kingdom, they asserted, had been meticulously classified long ago, and while new species - and even genera - were being found on an almost daily basis, no new insect orders had been discovered since Grylloblattodea in 1915. There could be no more revolutionary discoveries, no completely unknown types of insects. Scientists already knew all the basic insect forms.

They were wrong. For there was a mimic, hiding in plain view since the beginning of the 20th Century. Specimens of the mimic had been collected, examined, and tucked away to gather dust in the “unidentified” sections of museum collections. And it would be another sixty years before an alert student finally brought the mimic into the light. It’s a good thing this bug is about an inch long, rather than six feet, or we might have lost quite a few transients before discovering it.

The mimic is called a Mantophasmid, or gladiator, and its discovery has been a wake-up call to the whole of the entomological community.



DISCOVERY

While credit for the discovery of Mantophasmatodea is shared between four researchers, the person who first noticed that “one of these bugs is not like the others” was Oliver Zompro, a student at the Max Planck Institute for Limnology. The first mantophasmid specimens he found were a group of larvae encased in amber, found in the Baltic region. Later, when he was doing research at the Natural History Museum of London, a curator showed him the desiccated and unidentifiable remains of an unknown bug collected in Tanzania in 1950. When another piece of amber containing an adult male mantophasmid was sent to Zompro, he realised that all three of these unknown insects were remarkably similar. He showed his findings to his thesis adviser, Joachim Adis, who suggested that he search for similar specimens in other European museums.

After months of searching through the collections of various institutes, Zompro located a fourth specimen in Berlin. This one was an adult female that had been collected in Namibia in the beginning of the 20th Century. With a variety of specimens now available to them, Zompro and Adis almost immediately realised that this was not just another new species of mantid or walkingstick, as they had first assumed, but a completely different kind of insect, different enough to warrant the declaration of a whole new insect order.

‘We settled on the scientific name Mantophasmatodea because the animals look like a bizarre cross between a mantis (order Mantodea) and a walkingstick (order Phasmatodea). But among ourselves we took to calling the beasts “gladiators,” inspired by their fearsome appearance and the armor that covers them as nymphs.’

Subsequent research turned up several more specimens, collected in the last decade in Namibia, on an isolated massif known as the Brandberg, or Daures. In February 2002, a team of scientists flew to the Brandberg to search for living gladiators. They soon found numerous specimens falling into several species. Although they did not have a chance to make any detailed studies of the mantophasmids, they had found enough to make a public announcement of their discoveries, and in April 2002 they announced the first new insect order since 1915.

Further field studies have found gladiators thriving throughout South Africa’s Western Cape province, and several dozen more previously unidentified specimens have been found in various South African museums. Far from being an extremely rare animal living in a single inaccessible location, Mantophasmatodea is actually rather common within a small, but fairly well-studied territory.



THE GLADIATORS

The members of Order Mantophasmatodea look and act like a strange cross-breeding of mantids, grasshoppers and walkingsticks, but the combination of characteristics and behaviour is unique to this order. Gladiators are wingless, nocturnal predators, gripping their prey with thorny front legs like mantids. They have strong hind legs like grasshoppers, and their general body shape is long and tubular like that of a walkingstick.

Five species of gladiators are now known. Three of these are now living, while two others are known only from specimens fossilized 45 million years ago. The living species have been classified in two genera.

Gladiator larvae grow quickly, molting several times. In the nymph stage, their exoskeleton grows into thick armour. The adult insect is not armoured, but some species do bear spines. These spines are probably meant for camouflage through contour elimination, not an actual defense. Nymphs and adults of all species are well camouflaged in their native environments, like most mantids and walkingsticks.

Mantophasmids are odd-looking beasts, and every photograph I’ve seen looks like a completely different insect. Seen from the side, they look a lot like stubby mantids, except their heads are more like those of grasshoppers. From the top, they look like fat stick insects. In fact, the resemblances are mostly superficial, and there is quite a bit of confusion over the order’s proper placement in the insect class. Nobody can tell for sure what they evolved from, or how closely related they are to any other order, although there is DNA testing underway that should eventually give us a better idea.

We do know that the primitive gladiators had more triangular heads that looked quite similar to mantids, as well as thicker, presumably stronger front legs. This hints at a common ancestor with the modern mantids. However, all known gladiator species are wingless, like walkingsticks, and have strong hind legs for jumping, like grasshoppers (but not as strong). The males of the species use these strong legs to jump onto the females during mating, holding their mates firmly with the four front arms. According to some reports, many males still fall victim to the females in the well-known mantid fashion.

When not eating each other, gladiators eat a wide variety of insects, such as moths, silverfish and cockroaches. They pounce on them and pin them down with their forelegs, using all four front legs to hold larger prey. The prey is eaten alive while the gladiator’s spiked front legs hold it immobile. Every part of the victim is eaten except for the wings and legs.



HERE (STILL) BE DRAGONS

In the final scene of Wollheim’s “Mimic”, the narrator watches a swarm of newly hatched mimics burst out over the rooftops, only to be chased by yet another unknown species - a giant moth-like insect that had lain in wait on a nearby building, its great wings perfectly mimicking a shingled roof. As he watches the strange creatures flying away, he wonders with horror what other unknown species are living amongst us.

Entomologists, on the other hand, have reacted to the discovery of Mantophasmatodea with great joy. For them, the discovery of the thirty-first insect order is a wondrous sign that there are still major discoveries to be made, that the mystery of the great unknown has not yet been eliminated. To use the words of the discoverers themselves, ‘the natural world suddenly seems a bit wider and wilder than we had imagined it to be.’



REFERENCES:

  • ADIS, J., ZOMPRO, O., MOOMBOLAH-GOAGOSES, E. & MARAIS, E. (2002), Gladiators: A New Order of Insect Scientific American
  • THERON, H. (2002), Entomologists amazed by new insect order from Namaqualand Science in Africa.
    http://www.scienceinafrica.co.za/2002/October/insect.htm