Tag: biodiversity

Scientist collects 30 sawfly species not previously reported from Arkansas

Sawflies and wood wasps form a group of insects that feed mainly on plants when immature. Field work by Dr. Michael Skvarla, which was conducted during his Ph.D. research at the University of Arkansas, Fayetteville, USA, has uncovered 30 species of these plant-feeding wasps that were previously unknown in the state. The study is published it in the open access journal Biodiversity Data Journal.

After collecting sawflies in tent-like Malaise traps or hanging funnel traps, Dr. Michael Skvarla sent the specimens to retired sawfly expert Dr. David Smith for identification.

In total, 47 species were collected, 30 of which had not been found in Arkansas before. While many of the species are widespread in eastern North America, eight species were known only from areas hundreds of kilometers away.

“I knew that many insect groups had not yet been surveyed in Arkansas, but I was surprised that 66% of the sawfly species we found were new to the state,” Skvarla says.

“In addition, over a quarter of the newly recorded species represent large range extensions of hundreds of miles; Monophadnoides conspiculatus, for instance, was previously known only from the Appalachian Mountains. This work highlights how much basic natural history is left to discover about insects.”

Sawflies and wood wasps comprise the wasp suborder Symphyta and derive their common names from the serrated or saw-shaped ovipositor many species use to lay eggs into plant tissue, and because some species bore into wood.

While some sawfly and woodwasp species can be pests on crops or ornamental plants, most do not pose an economic concern, and all are harmless to people.

###

Original source:

Skvarla M, Smith D, Fisher D, Dowling A (2016) Terrestrial arthropods of Steel Creek, Buffalo National River, Arkansas. II. Sawflies (Insecta: Hymenoptera: “Symphyta”). Biodiversity Data Journal 4: e8830. doi: 10.3897/BDJ.4.e8830

The first long-horned beetle giving birth to live young discovered in Borneo

A remarkably high diversity of the wingless long-horned beetles in the mountains of northern Borneo is reported by three Czech researchers from the Palacký University, Olomouc, Czech Republic. Apart from the genera and species new to science, the entomologists report the first case of reproduction by live birth in this rarely collected group of beetles. The study was published in the open access journal ZooKeys.

Generally, insects are oviparous, which means that their females lay eggs and the embryonic development occurs outside the female’s body. On the other hand, ovoviviparous species retain their eggs in their genital tracts until the larvae are ready to hatch. Such mode of reproduction is a relatively rare phenomenon in insects and even rarer within beetles, where it has been reported for a few unrelated families only.

The long-horned beetles are a family, called Cerambycidae, comprising about 35,000 known species and forming one of the largest beetle groups.

“We studied the diversity of the rarely collected wingless long-horned beetles from Borneo, which is one of the major biodiversity hotspots in the world,” says main author and PhD student Radim Gabriš. “The mountains of northern Borneo, in particular, host a large number of endemic organisms.”

The scientists focused on the group which nobody had studied in detail for more than 60 years. They found surprisingly high morphological diversity in this lineage, which resulted in the descriptions of three genera and four species new to science.

“During a dissection of female genitalia in specimens belonging to the one of the newly described genera, named Borneostyrax, we found out that two females contained large larvae inside their bodies,” recalls Radim Gabriš. “This phenomenon have been known in a few lineages of the related leaf beetles, but this is the first case for the long-horned beetles.”

However, according to the authors, the modes of reproduction remain unknown for many beetle lineages besides Cerambycidae, so the ovoviviparity might be, in fact, much more common. Further detailed studies are needed for better understanding of the reproductive strategy in this group.

###

Original source:

Gabriš R, Kundrata R, Trnka F (2016) Review of Dolichostyrax Aurivillius (Cerambycidae,Lamiinae) in Borneo, with descriptions of three new genera and the first case of (ovo)viviparity in the long-horned beetles. ZooKeys 587: 49-75. doi: 10.3897/zookeys.587.7961

Curious new bush species growing ‘bleeding’ fruits named by a US class of 150 7th graders

A class of 150 US 7th graders has helped select a name for a newly discovered plant, which amazes with its fruits that appear to be bleeding once they are cut open. Bucknell University biology professor Chris Martine and life science teacher Bradley Catherman challenged the students to come up with ideas for what to call the new Australian species last spring.

Looking for a way to engage local youngsters in biodiversity science, Martine scheduled a presentation to the collective 7th grade life science classes at Donald H. Eichhorn Middle School. As the day of his assembly approached, he started to think that the best way to generate interest might be to somehow allow the students to participate in the actual research he was doing in his lab at the time. Only, he knew there were few things he could do with 150 13- and 14-year olds sitting in a gymnasium.

“I emailed Mr. Catherman and I said, ‘How about we ask them to name a new species for me?’ explained Martine. “And then I showed up with live plants, preserved specimens, and my notes from the Outback – and we said, ‘Go ahead, tell us what to call this thing.'”

Nearly a year later, Martine and his co-authors, including two undergraduate students, have published the new species in the open access journal PhytoKeys. The news is coming just in time for the National Teacher Appreciation Day, thus giving tribute to Bradley Catherman, a life science teacher who is not afraid to step beyond the standard curriculum and make that extra step to actually engage his students with their studies.

“I was really impressed with Mr. Catherman’s willingness to work outside of the typical curriculum on this,” said Martine, “In an age when K-12 teachers are increasingly pressured to ‘teach to the test’ he is still willing to think creatively and try something unusual.”

Curiously, the new flowering bush species ‘behaves’ nothing like an ordinary plant. While its unripened fruits are greenish white on the inside when cut open, they start ‘bleeding’ in no more than two minutes. The scientists have even filmed a video short showing how their insides turn bloody scarlet at first, before growing darker, appearing just like clotting blood.

A week after the presentation, each of the students submitted an essay in which they suggested a name, explained the meaning, and translated it into Latin (the language that scientific names are required to be in). Catherman and Martine then selected the two best essays for the inaugural Discovery Prize, a new middle school science award established by Martine and his wife, Rachel.

“As you might imagine, the suggestions ran the gamut from the silly to the scientific,” said Martine. “But for every request to name the species after a favorite food, family pet, or Taylor Swift, there were many suggestions based on the data the students had been provided.”

According to Martine, a number of the students suggested names based on two characteristics of the plant’s berries: the ‘bleeding’ unripened fruits and the dry and bone-hard mature ones. Based on this, the plant will now be known as Solanum ossicruentum, best translated to Australian blood bone tomato, with “ossi” meaning “bone” and “cruentum” meaning “bloody”. The species belongs to the genus of the tomato.

The species is native to the sub-arid tropical zone of northern Australia. Martine collected the seeds, he grew his research plants from, during a 2014 expedition to Western Australia and the Northern Territory. However, specimens of the plant had actually been gathered for years before then.

“This is just one of thousands of unnamed Australian species that have been collected by dedicated field biologists and then stored in museums,” said Martine, who studied specimens of the new species in the Northern Territory Herbarium before hunting for it in the bush.

“There is a wealth of museum material just waiting to be given names – and, of course, the organisms represented by those specimens await that recognition, as well as the attention and protection that come with it.”

Luckily for Solanum ossicruentum, attention and protection are not too much of an issue.

“Not only is it widespread and fairly abundant,” said Martine, “but one of the healthiest populations occurs in Mirima National Park, a popular and easily-accessible natural area just outside the Western Australian town of Kununurra.”

“Plus, middle schoolers can be tough to deal with. I don’t think anyone in their right mind would mess with this plant, now,” the botanist joked.

###

Original source:

Martine CT, Cantley JT, Frawley ES, Butler AR, Jordon-Thaden IE (2016) New functionally dioecious bush tomato from northwestern Australia, Solanum ossicruentum, may utilize “trample burr” dispersal. PhytoKeys 63: 19-29. doi: 10.3897/phytokeys.63.7743

Flightless survivors: Incredible invertebrate diversity in Los Angeles metropolitan area

Urban wildlife is surprisingly understudied. We tend to know more about animals in exotic places than about those that live in our cities.

This is why researchers Emile Fiesler, president of Bioveyda Biological Inventories, Surveys, and Biodiversity Assessments, USA, and Tracy Drake, manager of the Madrona Marsh Preserve, looked into the fauna of the Madrona Marsh Preserve, California, a small nature preserve in one of the world’s largest metropolitan areas.

Consequently, they published the astonishing number of 689 species of invertebrates, which have managed to survive decades of farming and oil exploration, followed by development pressures, in the open access Biodiversity Data Journal. The study was minimally invasive as the live animals have been recorded with macro-photography.

Even though it is the insects that first developed the ability to fly, long before the dinosaurs became birds, the latter have always received the most of our attention. This major evolutionary breakthrough, which has occurred more than once in the past, is also a reason why insects are currently the most diverse animals on earth in terms of number of species.

“Insects and other invertebrates have filled all ecological niches and all corners of our planet,” explain the authors. “No surprise that these small creatures conquered our cities and invaded our homes as well.”

Most of the urban dwellers, however, have been introduced – accidentally or deliberately – by humans.

“The remainder – native ‘wild’ species – are able to survive in the city mainly due to their adaptivity,” they point out. “It is therefore surprising to find a number of flightless species in a small area surrounded by urbanization.”

The Madrona Marsh Preserve is located in Torrance, which is part of the Los Angeles metropolitan area. The greater Los Angeles Metropolitan area is one of the world’s largest, with a human population of more than 17 million.

The Madrona Marsh Preserve, boasting seasonal wetlands, is well known as a birdwatchers’ paradise. Besides birds, its other vertebrates (mammals, reptiles, amphibians, and fishes), as well as its flowering plants, are relatively well known. The invertebrate fauna of the Preserve, on the other hand, aside from butterflies and dragonflies, was virtually unknown.

Interestingly, night surveys revealed the presence of a ‘second shift’ diversity, or creatures seemingly complementary to those active during the day.

Among the long-time survivors are wingless camel crickets as well as velvet ants, which are wasps whose flightless females look like furry ants. Another curiosity that intrigued the researchers is an obscure flightless female bradynobaenid wasp.

The researchers were especially surprised by their encounter with a large Solifugid [image 3] – also known as Camel Spider or Wind Scorpion. Solifugids are little-known arachnids that are neither spiders, nor scorpions, and can grow up to 15 cm (6 in). Their order’s name Solifugae translates from Latin as “those that flee from the sun”.

All in all, the biodiversity study resulted in 689 species without a backbone, belonging to 13 classes, 39 orders, and 222 families, found on this island surrounded by urbanization.

“Not unlike the moas and dodos, these ‘island’ inhabitants stayed grounded through the ages,” acknowledge the researchers.

###

Original source:

Fiesler E, Drake T (2016) Macro-invertebrate Biodiversity of a Coastal Prairie with Vernal Pool Habitat. Biodiversity Data Journal 4: e6732. doi: 10.3897/BDJ.4.e6732

About the authors:

Emile Fiesler is president of Bioveyda Biodiversity Inventories, Surveys, and Studies, and Tracy Drake is manager of the Madrona Marsh Preserve.

A new scorpion from California reveals hidden biodiversity in the Golden State

California is known for its high biological diversity. The state encompasses a wide variety of habitats, from temperate coastal scrub and cool redwood forests to high-elevation conifer forests and grasslands that are home to an equally diverse variety of plants and animals. Biologists have been intensively studying and characterizing the biodiversity of California for centuries.

Recent fieldwork by researchers Warren Savary and Rob Bryson uncovered a new species of scorpion in the foothills of the Sierra Nevada in northeastern California. It is related to several species in the genusPseudouroctonus, and is only the fourth new species of scorpion to be described from California in the past twenty years. The description is published in the open access journal ZooKeys.

The lead author, Warren Savary, is a field associate of the California Academy of Sciences and has been studying the scorpion diversity of California since the 1970s. He and a collaborator described a new species endemic to the White and Inyo Mountains in eastern California in 1991.

“California is home to a remarkable variety of scorpions,” says Savary. “However, the more I study them, the more I realize that we’ve only just scratched the surface. A lot of scorpion diversity remains to be described.” He and co-author Rob Bryson, a researcher at the University of Washington, have started using DNA to help better understand scorpion diversity.

“Scorpions have been around for a long time — over 400 million years — and many are quite similar in general appearance,” comments Bryson. “We can use DNA sequences to help us piece together how scorpions have evolved and how they are related. Despite looking similar, DNA often reveals that even assumed close relatives can be quite divergent.”

Savary and Bryson are working on publishing the descriptions of several other new species of scorpions from California. “2016 will be an exciting year for scorpion discoveries,” they promise.

###

Original source:

Savary WE, Bryson Jr RW (2016) Pseudouroctonus maidu, a new species of scorpion from northern California (Scorpiones, Vaejovidae). ZooKeys 584: 49-59. doi: 10.3897/zookeys.584.6026

New curiously scaled beetle species from New Britain named after ‘Star Wars’ Chewbacca

Chewbacca, the fictional ‘Star Wars’ character, has given his name to a new species of flightless beetle, discovered in New Britain, Papua New Guinea. Although Trigonopterus chewbacca was only one of the four black new weevil beetles found during the expedition, it stood out with its curious scales, which made the authors think of Han Solo’s loyal companion.

Scientists Dr Matthew H. Van Dam, SNSB-Zoological State Collection, Germany, Raymond Laufa, The University of Papua New Guinea and Dr Alexander Riedel, Natural History Museum Karlsruhe have their paper, where they describe the new species, published in the open access journal ZooKeys.

Failing to understand how was it possible that the hyperdiverse beetle genus Trigonopterus has never been spotted in New Britain, two of the researchers travelled to the island to double-check the foliage and leaf litter. Interestingly, the genus thrives best in Melanesia, the Oceania subregion, where Papua New Guinea is located, yet there had been only a single Trigonopterus species known from Bismarck Archipelago prior to the present study.

Eventually, having spent ten days sifting leaf litter and beating foliage, the authors discovered eighteen individuals in primary forests growing on limestone karst, and later assigned them to four separate species. However, these few findings are still striking, given the abundance of the beetles in similar localities in the New-Guinean mainland.

Unlike its sci-fi namesake, the Chewbacca beetle cannot rely on its measurements to scare other possibly malevolent species off. It only measures between 2.78 and 3.13 mm. Dissimilar again, is its body, which is black and rhomboid-shaped, while its legs and antenna appear rusty. What likens the beetle to “Chewie”, however, is its distinctively dense scales, covering its head and legs.

In conclusion, the authors note that the beetle genus must have colonised New Britain at least four times in the past. “Given the size, mountainous topography and tropical vegetation of New Britain, it is likely that Trigonopterus has undergone some local speciation on the island, but this possibility requires further investigation,” they say.

Original source:

Van Dam MH, Laufa R, Riedel A (2016) Four new species of Trigonopterus Fauvel from the island of New Britain (Coleoptera, Curculionidae). ZooKeys 582: 129-141. doi: 10.3897/zookeys.582.7709

New land snail species from Australia shows dissection not necessary to identify molluscs

Dissection might prove unnecessary when identifying new molluscs after scientists Corey Whisson, Western Australian Museum, and Dr Abraham Breure, Naturalis Biodiversity Centre, the Netherlands, and Royal Belgian Institute of Natural Sciences, Belgium, described a previously unknown land snail based on its genitalia, yet without damaging the specimen in the slightest. The new species is published in the open access journal ZooKeys.

The biologists described the first new Australian land snail species of this family for the last 33 years thanks to micro-computed tomography (micro-CT) and reconstruction with specialised software. This novel method, likely applied for identification of molluscs for the first time in history, uses X-rays to create cross-sections of the genitalia, so that a 3D model can be created without damaging the specimen. This can be then compared to known related taxa’s genitalia in order to show if there are enough differences to prove species delimitation.

The scientists note that despite the satisfying results, micro-CT is time-consuming and “quite laborious” approach. “However, in the case of a single or just a few specimens, this may be an alternative to destructive dissection,” says Dr Abraham Breure in his personal blog.

The new land snail, called Bothriembryon sophiarum after Dr Abraham Breure’s wife Sophie J. Breure and Corey Whisson’s first daughter Sophie Jade Whisson, can only be found along a 180-kilometre line running across the escarpment and cliff tops of the Baxter Cliffs and Hampton Ranges in Western Australia. Given its restricted distributional range, it is considered a short-range endemic.

The mollusc is characterised with a slender high-spired shell, built specifically for the demanding nature of its habitat. Dwelling in rocky limestone substrate, which is often fractured with narrow cracks and fissures, the snail has developed a slender shell, so that it can move easily through cavities and under rocks. On the other hand, being predominantly cream in colour with reddish or greyish brown blotches, it successfully blends with the limestone.

###

Original source:

Whisson CS, Breure ASH (2016) A new species of Bothriembryon (Mollusca, Gastropoda, Bothriembryontidae) from south-eastern Western Australia. ZooKeys 581: 127-140. doi:10.3897/zookeys.581.8044

Poorly known South African mountain endemic appears to be a very valuable keystone species

Mountain ecosystems are valuable providers of key resources including water. These ecosystems comprise diverse species, some of which appear to be especially important to the ecosystem’s functioning. In poorly studied mountain environments in biodiversity-rich countries, these keystone species can often be overlooked and undervalued.

Macowania is a group of yellow daisy shrubs occurring in the alpine-like regions of the Drakensberg and highlands of Ethiopia, Eritrea and Yemen. Doctoral student Joanne Bentley, University of Cape Town, studied the genetic relationships between the various Macowaniaspecies and relatives during her Masters degree studies. Her research led to the first collection of the poorly known species Macowania revoluta (known also as the Amathole Macowania) in about 40 years.

The story of Macowania revoluta is published in the open access journal PhytoKeys.

The Amathole Macowania appears to be an exceptionally important keystone species. This is because it forms one of the dominant members of the valuable mountain wetland communities and, thus, likely plays a very important role in wetland functioning and soil protection.

It appears to be somewhat tolerant of woody alien species and a valuable pioneer species protecting its native co-habitants. Plants like this one buffer more sensitive plants from sudden changes in environment (such as forestry, alien invasion and fire), and provide an opportunity for the ecosystem to ‘bounce back’.

Restricted to the Amathole mountains in the Eastern Cape Province, South Africa, the Amathole Macowania was first collected sometime before 1870 by the pioneer botanist Peter MacOwan, and was well documented until around 1949. After that, except for one record in 1976, the plant quietly disappeared.

“This was the first Macowania species that we found during our fieldtrip across the greater Drakensberg. We had combed several of the localities where it had been collected before; mostly from several decades ago, some from more than a century ago!” says Joanne Bentley. “We became increasingly doubtful about finding the plant, given the heavily transformed plantation landscape.”

“Ready to throw in the towel, we came across a peaty area on the margins of the forest and decided on one last investigation. We were lucky: it was growing prolifically! It was a very special moment.”

As it often happens, exciting discoveries come in bulk. Joanne’s discovery of the plant in July 2010 was followed by another record in October 2010, by the Curator of the Schonland Herbarium, Tony Dold. In 2014 at least three additional localities were recorded along the popular Amathole Hiking Trail by Dr Ralph Clark, Rhodes University. A further record was added in 2015 by Vathi Zikishe, South African National Biodiversity Institute. The verdict: this is a very localised but patchily abundant species, and an ecologically valuable component of the Amathole flora.

Listed as ‘Data Deficient’ in the Threated Plants List for South Africa, this string of modern records of the species also provided the first opportunity to get an idea of its ecology and abundance, as well as the first photographs.

“The practical value of this species in local land restoration projects still needs to be explored, but the opportunities are exciting,” says Dr Clark. “The discovery that this obscure endemic mountain plant is not only abundant, but is, in fact, fulfilling an extremely important ecological role, highlights the value of detailed mountain biodiversity research in southern Africa.”

###

Original source

Clark VR, Bentley J, Dold AP, Zikishe V, Barker NP (2016) The rediscovery of the Great Winterberg endemic Lotononis harveyi B.-E.van Wyk after 147 years, and notes on the poorly known Amathole endemic Macowania revoluta Oliv. (southern Great Escarpment, South Africa). PhytoKeys 62: 1-13. doi: 10.3897/phytokeys.62.8348

South African endemic mountain plant gives itself up after 147-year absence

South Africa’s mountains are essential to the economic well-being of the country, providing many goods and services essential for social and economic prosperity. However, the biodiversity value of these mountains is still poorly understood. This is exemplified by the large number of plant species still only known from one or two collections made well over a century ago.

The Great Escarpment Biodiversity Research Programme, led by Prof. Nigel Barker, University of Pretoria, has been systematically documenting plant diversity and endemism along much of the Great Escarpment – southern Africa’s principal mountain system.

“This ‘un-sexy’ foot-slogging research has yielded a number of valuable discoveries and rediscoveries, highlighting the biodiversity value of these mountains,” points lead author Dr Ralph Clark, Rhodes University, South Aftica.

One of these rediscoveries is a plant last seen only by one more person: Mrs Elizabeth Barber, one of South Africa’s finest women botanists of the 19th century. Mrs Barber has been a regular correspondent with Charles Darwin and has provided material of South African plants to numerous institutions in Europe.

“Her discovery – Lotononis harveyi, also known under the common name ‘Mrs Barber’s Beauty’ in her honour, was published in 1862, but unfortunately, as her specimen did not include a date, we do not know the actual year in which she discovered it,” he explains. “What we do know, is that it mysteriously disappeared for at least 147 years, despite attempts to relocate it.”

In 2009, Dr Ralph Clark undertook an extensive collecting trip to the Great Winterberg, where he accidently stumbled across a flowering specimen of ‘Mrs Barber’s Beauty’. It was only in 2014, however, that the plant was properly recognised for what it was, and a second trip was quickly planned.

The results of the second trip included the first photographs and ecological records of this apparently scarce species. Dr Clark’s results have been published in the open access journal PhytoKeys.

“There are currently only six known individuals of this species. The main limiting factors appear to be fire and grazing, the plants only occurring where these two prominent ecological actors have been excluded for some time,” notes Dr Clark.

“However, with much of these mountains still poorly explored by biodiversity scientists, it is possible that additional individuals will come to light. For now the species will be regarded as Critically Endangered.”

###

Original source:

Clark VR, Bentley J, Dold AP, Zikishe V, Barker NP (2016) The rediscovery of the Great Winterberg endemic Lotononis harveyi B.-E.van Wyk after 147 years, and notes on the poorly known Amathole endemic Macowania revolutaOliv. (southern Great Escarpment, South Africa). PhytoKeys 62: 1-13. doi: 10.3897/phytokeys.62.8348

The city of angels and flies: 12 unknown scuttle fly species have been flying around L.A.

Although the second-largest and rather concrete metropolis in the United States might not be anywhere near one’s immediate association for a biodiversity hotspot, the fly fauna of Los Angeles is quite impressive. As part of BioSCAN, a project devoted to exploring the insect diversity in and around the city, a team of three entomologists report on their latest discovery – twelve new scuttle fly species. Their study is published in the open access Biodiversity Data Journal.

Launched in 2013, the Natural History Museum of Los Angeles County‘s project BioSCAN seems to never cease to amaze with large numbers of newly discovered species. The first phase of the study finished with 30 species of flies new to science from sites in 27 backyards, 1 community garden, the Los Angeles Ecovillage, and the Nature Gardens at the Museum. In recognition to the residents, who had literally let the scientists in their homes, each of those flies was named after the relevant site’s host.

When they decided to revisit the specimens they had collected during the first year of the project as well as older museum collections, the authors of the present paper were in fact quite certain they were about to find a new batch of unknown flies.

Having already described so many new scuttle fly species, the latest twelve had initially gone undercover, all being rare and often represented by only one specimen among the total of 43,651 collected individuals.

“The remarkable diversity of biologies of these flies makes them a varied and essential group to document in any ecosystem,” the entomologists explain.

The extensive BioSCAN project is still ongoing thanks to its passionate staff, international collaborators and advisors, as well as the large number of students and volunteers. Being especially grateful for their help, the scientists have named one of the fly species M. studentorum and another one – M. voluntariorum. The project is currently in its second phase of collecting.

“These volunteers are critical to our operation, and have contributed to everything from public outreach in the NHM Nature Lab to specialized work on phorid flies,” point out the authors.

In the end, the researchers hope that they will get their message across to other taxonomists, funding agencies, institutions and the public alike. Urban environments with their fast-changing conditions and biodiversity profile, need constant attention and scientific curiosity.

“There is an enormous taxonomic deficiency, including, or, perhaps, especially, in rapidly changing urban environments,” they say. “Taxonomists and their funding agencies must give time, attention and money to the environments surrounding their towns and cities.”

“Baseline collections of urban fauna must be established in the present if there is hope for understanding the introductions and extinctions that will occur in the future,” they stress.

###

Original source:

Hartop E, Brown B, Disney R (2016) Flies from L.A., The Sequel: A further twelve new species ofMegaselia (Diptera: Phoridae) from the BioSCAN Project in Los Angeles (California, USA).Biodiversity Data Journal 4: e7756. doi: 10.3897/BDJ.4.e7756