Tag: weevil

New Chinese leaf-roller weevil does not know how to roll leaves

A long-term project on insect-seed interactions, currently being carried out by researchers of the Institute of Zoology (Chinese Academy of Sciences) in a subtropical forest near Dujiangyan City, Sichuan, China, revealed the presence of larvae of an unknown weevil species eating the seeds in the pods of a shrubby legume.

Scientists from the Institute of Zoology, China, Xiangyang Lv, Zhishu Xiao, Zhiliang Wang, Runzhi Zhang, and Miguel A. Alonso-Zarazaga, also affiliated with the Museo Nacional de Ciencias Naturales (CSIC), Spain, published the description of the new genus and species, named Evemphyron sinense, and added data on its biology in the open access journal ZooKeys.

Because of its peculiar features, it was difficult to locate the closest relatives of this new species. However, a few characteristic traits of the body and genitalia, strongly pointed to its placement within the tribe Deporaini.

The closest, although seemingly rather far-related to the new species, beetles are considered to be a genus with scattered distribution, stretching from the Russian Far East to the Indian Himalaya.

However, they are smaller weevils whose females cut shoots to lay their eggs. On the other hand, the males in both genera share a peculiar patch of hairs, probably related to pheromone dispersal. Likewise, each species is associated with legumes.

The curious feature of this weevil group (Deporaini) is that the vast majority of its species are leaf-rollers. The females cut a hardwood leaf in a peculiar and mathematical way and roll it, laying one egg inside each one. This behaviour, which is known in other far-related weevils of the same family, seems to have appeared independently in different evolutionary branches. In the case of Deporaini, this behavioural trait evolved after the new genus became a distinct one.

As a result, the new genus is considered to be one of the two most primitive within the tribe. In fact, it might be the most primitive one, taking into account a number of morphological traits as well.

It could be that the new beetle never knew how to roll a leaf to make nests and shelter its offspring.

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Original source:

Lv X, Alonso-Zarazaga MA, Xiao Z, Wang Z, Zhang R (2016) Evemphyron sinense, a new genus and species infesting legume seedpods in China (Coleoptera, Attelabidae, Rhynchitinae).ZooKeys 600: 89-101. doi: 10.3897/zookeys.600.6709

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

Twenty-four new beetle species discovered in Australian rain forests

As many as twenty-four new species from Australian rainforests are added to the weevil genus Trigonopterus. Museum scientists Dr. Alexander Riedel, State Museum of Natural History Karlsruhe, Germany, and Rene Tanzler, Zoological State Collection Munich, Germany, have first discovered them among unidentified specimens in different beetle collections. The study is published in the open-access journal ZooKeys.

Australia is well known for its extensive deserts and savanna habitats. However, a great number of native Australian species are restricted to the wet tropical forests along the east coast of northern Queensland. These forests are also the home of the recent discoveries.

Most of the weevil species now recognised as new have already been collected in the 80s and 90s of the past century. Since then they had been resting in museum collections until German researcher Alexander Riedel had the opportunity to study them.

“Usually a delay of decades or even centuries occurs between the encounter of a new species in the field and its thorough scientific study and formal naming,” he explains. “This is due to the small number of experts who focus on species discovery,” he elaborates. “There are millions of unidentified insect specimens stored in collections around the world but only few people have the training necessary to identify those of special interest.”

However, old museum specimens alone are not enough either. Nowadays, researchers try to include DNA data in their descriptions, and the necessary sequencing techniques work more efficiently with freshly collected material. Therefore, the scientists set off to the field after they have studied the collections of others. Nevertheless, the German team were led to the discovery of one additional new species, which had never been seen before. They called itTrigonopterus garradungensis after the place where it was found.

All of the newly described weevils are restricted to small areas. Some are found only in a single locality. Presumably, this is a consequence of their winglessness, which has prevented them from spreading around. Furthermore, most of them dwell in the leaf litter where they are easily overlooked. Usually, they come to light during specific surveys of the litter fauna.

This is what Geoff Monteith from the Queensland Museum in Brisbane, for instance, has done in the past. As a result, his work is now relevant to conservation because highly localised species are extremely vulnerable to changes of their habitat such as climate change or the arrival of invasive species.

It is likely that Trigonopterus weevils have originated in Australia, the oldest landmass in the region. The island of New Guinea is geologically much younger, but there the genus has quickly enough diversified into hundreds of species. Studies investigating such evolutionary processes depend on names and clear diagnoses of the species. As a result of the present research, for the Australian fauna these are now available.

Besides the publication in the open-access journal ZooKeys, high-resolution photographs of each species are uploaded to the Species ID website, along with the scientific description. All this puts a face to the species name, and therefore is an important prerequisite for future studies on their evolution.

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Original Source:

Riedel A, Tanzler R (2016) Revision of the Australian species of the weevil genus Trigonopterus Fauvel. ZooKeys 556: 97-162. doi: 10.3897/zookeys.556.6126

Lava attraction: 74 new beetle species found hiding in plain sight on a Hawaiian volcano

Confined to the limits of Haleakala volcano, Maui Island, Hawaii, the beetle fauna there turns out to be not only extremely diverse, but very abundant as well. When Prof. James Liebherr of the Cornell University Insect Collection thoroughly sampled beetle populations on the volcano, he identified 116 species of round-waisted predatory beetles, including 74 new to science. The taxonomic revision, complete with descriptions of the new species, is now published in the open-access journal ZooKeys.

The present discoveries and observations are certainly surprising due to their scale, even though it has been long known that the Hawaiian Islands support disproportionately high levels of biodiversity. For this group of native round-waisted beetles, called Mecyclothorax in the zoological naming system, there are 239 species across the Hawaiian Islands, all of them descended from a single colonizing species.

The 116 species known from Haleakala make that volcano the center of biodiversity for this group within Hawaii. These beetles’ evolution during the 1.2-million-year lifespan of Haleakala volcano means they have speciated faster than most organisms on Earth, including the Hawaiian Drosophila and the cichlid fishes of eastern Africa.

No less striking is the fact that the 74 newly described beetle species previously evaded discovery within the limits of Haleakala’s 1,440 km2 of surface area. Reasons for this include the restricted distributions of many of the beetle species, and the previous lack of comprehensive field sampling. During his research, Prof. Liebherr examined all quarters of the mountain to eventually find many places of 1′ latitude × 1′ longitude where more than 20Mecyclothorax species lived closely together within a limited area of forest.

Most of these diverse microhabitats were discovered in windward rainforests. Moreover, different forest areas, geographically isolated from each other by volcanic lava flows, steep valleys, or extensive mudflows, supported different sets of species. “Haleakala volcano is a large pie with different sets of beetle species living in the different slices,” comments Prof. Liebherr. “Actually the different pie slices are just like the original Hawaiian land divisions called ahu pua’a, showing that the Hawaiian people had a keen sense for how their island home was organized.”

Additionally, the round-waisted beetle species seem to thrive across a wide range of altitudes, with their populations covering the major part of the mountain’s height. Historical as well as modern records have identified representatives of these insects from 450-metre elevation up to the volcano’s summit at 3000 m. However, given land conversion and the influx of alien invasive plants, habitats below about 1000 m have been seriously disrupted, and these elevations support few native beetles.

Looking to the future, Liebherr points out that “the substantial level of sympatry, associated with occupation of diverse microhabitats by these beetles, provides ample information useful for monitoring biodiversity of the natural areas of Haleakala.”

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Original source:

Liebherr JK (2015) The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Haleakala-, Maui: Keystone of a hyperdiverse Hawaiian radiation. ZooKeys 544: 1-407. doi: 10.3897/zookeys.544.6074