Megalara garuda

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Découverte à Berlin d'une guêpe pas comme les autres !

L'entomologiste Michael Ohl a découvert récemment dans les collections du Musée d'Histoire Naturelle de Berlin, une nouvelle sorte de guêpe jusqu'alors inconnue. D'un noir intense, dotée de mandibules gigantesques et d'un corps surdimensionné, cette dernière ressemble davantage à une machine de guerre qu'à un insecte. Cinq fois plus grosse que les guêpes habituellement observées autour des sucrières posées sur les cafés-terrasses berlinois, cet insecte serait originaire de l'île de Sulawesi en Indonésie. Baptisée "Garuda", comme le symbole national indonésien d'un guerrier ailé, elle est actuellement étudiée dans les moindres détails par les deux spécialistes des guêpes, Michael Ohl et son collègue américain Lynn Kimsey de l'Université de Californie.

La Garuda fait désormais partie des 10.000 autres genres de guêpes déjà répertoriées. Ses 6 cm de longueur en moyenne comparés aux 15 mm réglementaires et sa couleur noire d'encre, font d'elle une espèce imposante et troublante, comme le déclare Michael Ohl.

Un point reste pour le moins à préciser : le comportement de l'insecte est mal connu, pour cause ce dernier n'a pas été observé en milieu naturel. Il est cependant fort probable que la taille gigantesque des mandibules joue un rôle prépondérant dans sa capacité à se défendre et l'aiguillon relié à une glande à venin à l'extrémité de son abdomen bien plus développé chez la Garuda, que chez aucune autre guêpe peut certainement infliger des morsures et déchirures extrêmement douloureuses. Cependant, il est intéressant de noter que seules les guêpes femelles, les ouvrières, ont la possibilité de paralyser leur ennemi par piqure grâce au venin de leur dard. Ce qui n'est pas le cas des mâles, qui pour se défendre n'utiliseront vraisemblablement que leurs mandibules.
Source:http://www.bulletins-electroniques.com/actualites/67621.htm

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UC Davis Entomologist Lynn Kimsey Discovers New Species of Wasp: Gigantic Wasp With Long, Powerful Jaws

DAVIS--A warrior wasp? A wasp with jaws longer than its front legs?

The new species of wasp that Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at the University of California, Davis, discovered on the Indonesian island of Sulawesi, has scientists abuzz.

The jaw-dropping, shiny black wasp appears to be the "Komodo dragon" of the wasp family.

It’s huge. The male measures about two-and-a-half-inches long, Kimsey said. “Its jaws are so large that they wrap up either side of the head when closed. When the jaws are open they are actually longer than the male’s front legs. I don’t know how it can walk. The females are smaller but still larger than other members of their subfamily, Larrinae.”

Kimsey discovered the warrior wasp on the Mekongga Mountains in southeastern Sulawesi on a recent biodiversity expedition funded by a five-year grant from the International Cooperative Biodiversity Group Program.

The first time I saw the wasp I knew it was something really unusual,” said Kimsey, a noted wasp expert who oversees the Bohart Museum's global collection of seven million insect specimens, including 500,000 wasps. “I’m very familiar with members of the wasp family Crabronidae that it belongs to but had never seen anything like this species of Dalara. We don’t know anything about the biology of these wasps. They are only known from southwestern Sulawesi.”

The large jaws probably play a role in defense and reproduction, she said. "In another species in the genus the males hang out in the nest entrance. This serves to protect the nest from parasites and nest robbing, and for this he exacts payment from the female by mating with her every time she returns to the nest. So it's a way of guaranteeing paternity. Additionally, the jaws are big enough to wrap around the female;s thorax and hold her during mating."

In her entire career as entomologist, she’s discovered close to 300 new species. But on three trips to Sulawesi, she’s brought back to the Bohart Museum “hundreds, maybe thousands of new species.”

“It will take years, maybe generations, to go through them all,” Kimsey said.

“I consider Sulawesi one of the world’s top three islands for biodiversity—that along with Australia and Madagascar.”

Sulawesi, a large Indonesian island located between Borneo and New Guinea, is known not only for its endemic biodiversity, but its rainforest and its proximity (three degrees) to the equator. Development threatens plant and animal life.

On the last three-week expedition, the UC Davis team of Lynn Kimsey, husband Robert Kimsey, a forensic entomologist in the UC Davis Department of Entomology, and Alan Hitch, assistant curator of the Museum of Wildlife and Fish Biology, hooked up with 12 scientists from the Indonesian Institute of Sciences (LIPI).

The insect-eating predator belongs to the genus Dalara and family Crabronidae. “I’m going to name it Garuda, after the national symbol of Indonesia,” Kimsey said. Garuda, a powerful mythical warrior that’s part human and part eagle, boasts a large wingspan, martial prowess and breakneck speed.

The 67-member expedition also included 12 members of Kendari's Chitaka mountaineering group, which guides mountain climbers to the top of the 9,117-foot volcanic peak; and a 40-member porter team that carried the equipment, set up camp and cooked the food, “which was steamed rice and ramen noodles three times a day,” she said.

“Eventually we had to leave because we ran out of food.”

The terrain was steep, slippery and overall, physically challenging, Lynn Kimsey said. “This part of Sulawesi gets about 400 inches of rain a year,” she said. “We were told that Sulawesi has a dry and rainy season. But the only difference we could see between the dry and rainy season is that during the dry season, it rains only in the afternoon.”

Kimsey expressed amazement at the biodiversity of the flora and fauna. “We saw a colonial spider web that stretched across two acres. The adult spiders were about two inches long.”

“We saw evidence of wild cows, anoa, found only in Sulawesi, and found the first record in that region of a (Sulawesi) palm civet, a weasel-like predator."

The director of the Bohart Museum since 1989, Kimsey is an insect taxonomist, specializing in bees and wasps and insect diversity. She received her doctorate in entomology from UC Davis in 1979 and joined the faculty in 1989.

Over the last four years, the international team of scientists has collected about a million specimens. Among the new species: a bat, two frogs, two lizards, two fish, a land crab and many insects.

Kimsey is a collaborator of a five-year $4 million grant awarded to UC Davis scientists in 2008 to study the biodiversity of fungi, bacteria, plants, insects and vertebrates on Sulawesi, all considered threatened by logging operations and mining developments. Much of the mountain was logged two decades ago and now there are plans for an open pit nickel mine, Kimsey said.

“There’s talk of forming a biosphere reserve to preserve this,” she said. “There are so many rare and endangered species on Sulawesi that the world may never see.”

An international team of collaborators is conducting biodiversity surveys, as well as screening microbes and plants for applications to human health and energy needs, recommending strategies to conserve endangered species, and developing and encouraging local conservation, according to principal investigator Daniel Potter of the UC Davis Department of Plant Sciences. Other collaborators from UC Davis are from the UC Davis Herbarium, Museum of Wildlife and Fish Biology, Plant Pathology and the Phaff Yeast Culture Collection in the Department of Food Science and Technology.

Size comparison: male (left) and female wasp of the newly discovered species. (Photo by Kathy Keatley Garvey)

Shortly after receiving the grant, Potter, a plant systematist at the Agricultural Experiment Station and director of the UC Davis Center for Plant Diversity, said: “The alarming rate at which biodiversity is being lost in many tropical regions has resulted in an urgent need for such efforts."

The International Cooperative Biodiversity Group Program is a multi-agency program led by the National Institutes of Health with contributions from the U.S. Department of Agriculture, Department of Energy, and the National Science Foundation.

As for the warrior wasp that Lynn Kimsey discovered, it’s now being intensely studied at the Bohart Museum of Entomology where she has long been known as “The Wasp Woman,” an affectionate term signifying her specialty.

The director of the Bohart Museum since 1989, Kimsey is an insect taxonomist, specializing in bees and wasps and insect diversity. She received her doctorate in entomology from UC Davis in 1979 and joined the faculty in 1989. Kimsey served as the interim chair of the UC Davis Department from 2008 to 2009.

Her mentor, the late professor Richard M. Bohart (1913-2007), for whom the museum is named, was world-renowned for his expertise on wasps and mosquitoes. Kimsey was his last graduate student.

During his career, Bohart identified more than one million mosquitoes and wasps, many now displayed at the Bohart Museum, a teaching, research and public service facility that he founded on campus in 1946.
Source: http://entomology.ucdavis.edu/news/warriorwaspnewspecies.html

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Tant que ces ''monstres'' ne viennent pas en France j'aurais pas fuir les piqures!

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Une guêpe de 6 centimètres découverte en Indonésie

Une entomologiste américaine a découvert une guêpe d'une taille impressionnante alors qu'elle était en expédition en Indonésie. Baptisé Megalara garuda, cet insecte mesure plus de six centimètres et le mâle est doté d'immenses mandibules.

La nouvelle "reine des guêpes" a été découverte sur l'île indonésienne de Sulawesi. Observée par l'entomologiste américaine Lynn Kimsey, de l'Université de Californie Davis, cette guêpe aux immenses mandibules - plus longues que ses pattes avant quand elles sont ouvertes - peut mesurer jusqu'à six centimètres. Le mâle peut atteindre cette taille impressionnante. La femelle, elle, est plus petite.

Baptisé Megalara garuda - le garuda est un oiseau mi-homme mi-aigle mythique emblématique de l’Indonésie - cet insecte appartient à la famille des guêpes fouisseuses, ainsi nommées car elles placent leurs larves dans un trou pour les nourrir. Cette famille compte plusieurs milliers d'espèces aux quatre coins du monde, expliquent dans leur étude publiée par la revue Zookeys Lynn Kimsey et son confrère Michael Ohl du Muséum d’histoire naturelle de Berlin. Un spécimen est conservé dans ce muséum depuis les années 1930. Mais il n'avait jamais été identifié.

Les femelles fouisseuses chassent leurs proies en les piquant, ce qui les paralysent. La sélection des proies est souvent spécifique à l'espèce, mais celles de la Megalara garuda n'ont pas encore été identifiées. Avec sa taille inhabituelle et les immenses mâchoires du mâle, cette nouvelle espèce diffère de toutes les autres guêpes fouisseuses connues. C'est la raison pour laquelle elle a été classée dans un nouveau genre, Megalara.

Les chercheurs savent encore peu de choses sur cet insecte. Mais ses grandes mandibules laissent penser que comme chez d'autres espèces ainsi pourvues, les mâles les utilisent pour maintenir la femelle pendant la copulation. Il est également possible qu'elles soient des armes de défense.
Source: http://www.maxisciences.com

Article:

http://www.pensoft.net/journals/zookeys/article/2475/abstract/megalara-garuda-a-new-genus-and-species-of-larrine-wasps-from-indonesia-larrinae-crabronidae-hymenoptera-

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