Entomologists amazed by new insect order from Namaqualand

THE RECENT recognition of a new order of insects, Mantophasmatodea, has been dubbed as "one of the most exciting" recent discoveries in Zoology, boosting the total number of insect orders (e.g. the beetles, flies, fleas, etc) to 30.

The formal description by entomologists of the fairly large, wingless creatures, which to the untrained eye resembles a cross between a grasshopper and a praying mantis, is the first description of an insect order since the discovery of ice crawlers (Grylloblattodea) in 1914, almost a century ago.

Small and bandy-legged, the wingless insects from the new order are aggressive carnivores, leaping on their prey and subduing them with their spiny legs. They walk on their heels, and are grey, brown or bright green in colour. The female is bigger than the male and often eats him after a prolonged and uninterrupted copulation of about three days. The female lays a series of up to 10 egg pods in the sand, each containing about 12 eggs, which hatch and develop during the wet winter months: adults appear in spring and die after about one month. The new order has no common name as yet.

Though scientists have found the insects embedded in Baltic amber, suggesting that they existed around 40 to 50 million years ago in Europe, the new order appears to be restricted to southern Africa in present times.

German insect anatomist Dr Klaus Klass and researchers Oliver Zompro, Prof Niels Kristensen and Prof Joachim Adis, described the new order in Science magazine (24 May, 2002, Volume 296, pp 1456-1459), based, on just two museum specimens from Tanzania and Namibia.

Dr Eugene Marais (Windhoek Museum, Namibia) then alerted these entomologists to a similar specimen in his collection, and in February this year led an expedition to Namibia's Brandberg, discovering one of the specimens described in the Science paper, plus another spiny species (dubbed the "gladiator").

The article caught the attention of UCT entomologist Dr Mike Picker. Though it referred to the Namibian and Tanzanian specimens, Picker realised he and his students had frequently encountered the insects in South Africa.

Picker wrote to Science reporting that he and students Jonathan Colville, Anthony Roberts and Mark Kirkman had previously noted the unusual orthopteriod insects in the semi-arid regions of the succulent Karoo (Namaqualand). "It emerged that we hadn't realised the evolutionary significance of the creatures we'd photographed in Namaqualand!" he added. He recovered 29 additional pinned specimens in South African museums, collected from 1890 to 1994. "Specimens from museum and field collections are currently known from about 30 localities, some of which are 600 km apart; and appear to represent at least four species," Picker reported.

After Picker's letter appeared, Klass contacted him, and they subsequently established a collaboration, the South African Mantophasmatodea Project, which brings together researchers from Japan, Germany, Denmark, the US and Namibia. (The Project also involves collaboration with the Iziko Museums of South Africa and the ARC–Plant Protection Research Institute in Pretoria.)

The team will study, among other aspects of the biology of the group, the relationship between the South African species and the Namibian species. Only a single family, Mantophasmatidae, is currently recognised. Three species have so far been identified in Namibia and at least four in South Africa.

Set against a universal scenario of shrinking biodiversity coupled with the increasing extinction rates, the find of a new group of animals so fundamentally different from all other insects groups both surprised and excited biologists, who had assumed that most major animal discoveries had already been made. The apparent centre of distribution of the group in the Succulent Karoo of South Africa adds yet another biological jewel to the already impressive concentration of endemic plants and insects of this region.

In the Zoology Department, the numerous cultures that daily consume vast quantities of drozzies (small vinegar flies) will hopefully provide answers to some fundamental questions, such as the evolutionary relationship of the Mantophasmatodea to the existing insect orders.

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