The Widow Next Door: Where is the globally invasive Noble False Widow settling next?

Noble false widow spider (Steatoda nobilis) at a public bus stop in the seaside resort of Lyme Regis, southern England. Photo by Rainer Breitling.

Spiders are one of the most successful groups of ‘invaders’ on the planet. Out of over 47,000 species of spiders known today, there are some that tend to follow humans across the globe and settle in habitats far away from their native homelands. A particularly notorious example is the species Steatoda nobilis, the Noble False Widow spider.

Originating from Madeira (Portugal) and the Canary Islands (Spain), the Noble False Widow has been rapidly spreading around the globe over the last few decades. While the species is already well established in Western Europe and large parts of the Mediterranean area, it has recently spread into California, South America and Central Europe. Meanwhile, its populations in England, where the spider used to be restricted to the very southern parts of the country, are now seen to experience a sudden expansion northwards.

As its name suggests, this is a relatively large species that resembles the well-known Black Widow and can inflict a painful – yet mostly harmless to humans – bite. Naturally, its ‘arrival’ causes widespread concerns and public disruptions. Specifically, the Noble False Widow poses a threat to native faunas, since it can prey on nearly every smaller animal thanks to its potent venom and sturdy webs.

Recently, experts and non-professional citizen scientists joined forces to reconstruct the invasion path of the Noble False Widow in Europe and the Americas, so that they could identify patterns and predict which regions are likely to be the next colonised by the spider.

By combining data from museum collections and the Spider and Harvestman Recording Scheme of the British Arachnological Society with published literature and their own observations from England, Germany, France and Ecuador, the researchers provided an unprecedented detailed view of the expansion of the Noble False Widow. The study, conducted by Tobias Bauer (State Museum of Natural History Karlsruhe), Stephan Feldmeier (Trier University), Henrik Krehenwinkel (Trier University and University of California Berkeley), Rainer Breitling (University of Manchester) and citizen scientists Carsten Wieczorrek and Nils Reiser, is published in the open-access journal Neobiota.

While it had largely been assumed that the Noble False Widow turned up in Europe along with bananas traded from the Canary Islands, a new look at the data revealed that the spiders have most likely been transported via imports of ornamental plants. Further, rather than the result of climate change, the establishment of the species across new, large territories is rather linked to the fact that these habitats all share similar conditions to the spider’s native localities.

“Similar suitable False Widow habitats occur in quite specific regions all around the globe,” explain the researchers. “Most importantly, South Africa, some areas in southern Australia, and a large part of New Zealand turn out to be highly likely targets for future invasions, unless appropriate import control measures are implemented.”

Global prediction of suitable regions for the Noble False Widow (Steatoda nobilis). Image by Stephan Feldmeier & Tobias Bauer.

In conclusion, the authors call for enhanced monitoring of the Noble False Widow as well as its still little known ecological impact on the environment in newly colonised areas. They also urge scientists in the predicted potential invasion target regions to search for specimens, especially in coastal cities.

 

Original source:

Bauer T, Feldmeier S, Krehenwinkel H, Wieczorrek C, Reiser N, Breitling R (2019) Steatoda nobilis, a false widow on the rise: a synthesis of past and current distribution trends. NeoBiota 42: 19-43. https://doi.org/10.3897/neobiota.42.31582

Right under our noses: A novel lichen-patterned spider found on oaks in central Spain

It happened again, a previously unknown spider species, whose home is a strongly humanised European country, appears to have been quietly and patiently waiting to get noticed until very recently.

Living on the trunks of oaks in Spain, the new species would have probably been spotted decades ago, had it not been for its sophisticated camouflage, which allows the small arachnid to perfectly blend with the lichens naturally growing on the tree.

Going by the name Araneus bonali, the new species was discovered on isolated trees at the borders of cereal fields by the scientists Eduardo Morano, University of Castilla-La Mancha, and Dr Raul Bonal, University of Extremadura. Their study is published in the open access journal ZooKeys.

Curiously enough, this is the same habitat, where the team found another new spider in 2016.

“How many new species remain unknown in these isolated oaks that once formed vast forests now becomes one even more intriguing question,” say the researchers.

“Anyone going for a walk around any village or park in central Spain would have been close to the new species. However, noticing it requires not only curiosity, but also a good sight, as its lichen-like colours make up an excellent mimicry.”

Lichens growing on an oak trunk at the study site in central Spain.

The similarity between the adults and the lichens that cover the oak trunks they inhabit is remarkable. Meanwhile, the greenish juveniles live amongst the green new shoots in the oak canopy until they reach maturity.

Whether the spider uses its mimicry to avoid predators or rather surprise its prey remains open for further investigation.

The description of this new species that belongs to the popular group of orb-weavers once again stresses the need of working harder on completing the list of spiders living in the Old World, such as the countries in the Mediterranean basin – a region that certainly keeps more taxonomic surprises up his sleeve.

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Original source:

Morano E, Bonal R (2018) Araneus bonali sp. n., a novel lichen-patterned species found on oak trunks (Araneae, Araneidae). ZooKeys 779: 119-145. https://doi.org/10.3897/zookeys.779.26944

Out of the darkness: A new spider found deep within an Indiana cave

Lead author Marc Milne in the Stygian River Cave and a male specimen of the newly described Islandiana lewisi 

Spiders are ubiquitous within our forests, fields, and backyards. Although you may be used to seeing the beautiful yellow and black spiders of the genus Argiope in your garden, large ground-scurrying wolf spiders in your yard, or spindly cellar spiders in your basement, this new sheet-web-building spider is probably one you haven’t seen before. The reason is that it’s known from a single cave in the world, Stygeon River Cave, in southern Indiana.

The University of Indianapolis assistant professor, Dr. Marc Milne, described the rare species in the open access journal Subterranean Biology with the help of a University of Indianapolis alumnus, Elizabeth Wells, who illustrated the spider for the manuscript.

Sheet weavers, also known as dwarf spiders or money spiders, are minute creatures growing no larger than a few centimetres in length, which makes them particularly elusive. Their peculiar webs are flat and sheet-like, hence their common English name.

Female of the new species Islandiana lewisi

The new spider, Islandiana lewisi, is an homage. Milne was shown the spider by a fellow scientist, Dr. Julian Lewis, who noticed the critter on one of his many cave expeditions. In appreciation for his help, Milne and Wells named the spider after Lewis.

This is the fifteenth species in its genus (Islandiana) and the fifth known to live exclusively in caves. It has been over 30 years since the last species has been added to this group.

At about 2 mm in size, Islandiana lewisi is thought to feed on even smaller arthropods, such as springtails living in the debris on the cave floor. It is unknown when it reproduces or if it exists anywhere else. The spider is likely harmless to humans.

The collectors of the spider, Milne and Lewis, described the hostile conditions within the cave, which the new species calls home: “because the cave floods from time to time, the insides were wet, muddy, slippery, and dangerous to walk on without the proper equipment.”

Milne and Lewis found the spider in small, horizontal webs between large, mud-caked boulders in the largest room in the cave. It was collected in October 2016 with the permission of the landowner.

Milne hypothesized that he had collected something special, stating, “I didn’t know what the spider was at first, I just thought it was odd that so many were living within this dark cave with no other spider species around.”

After returning to the lab and inspecting the spider under a microscope, Milne initially misidentified the species. However, when he re-examined it months later, he realized that the species was indeed new to science.

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Original source:

Milne MA, Wells E (2018) A new species of spider (Araneae, Linyphiidae, Islandiana) from a southern Indiana cave. Subterranean Biology 26: 19-26. https://doi.org/10.3897/subtbiol.26.25605

Six new species of goblin spiders named after famous goblins and brownies

 

Fictional characters originally ‘described’ by famous English children’s writer Enid Blyton have given their names to six new species of minute goblin spiders discovered in the diminishing forests of Sri Lanka.

The goblins Bom, Snooky and Tumpy and the brownies Chippy, Snippy and Tiggy made their way from the pages of: “The Goblins Looking-Glass” (1947), “Billy’s Little Boats” (1971) and “The Firework Goblins” (1971) to the scientific literature in a quest to shed light on the remarkable biodiversity of the island country of Sri Lanka, Indian Ocean.

As a result of their own adventure, which included sifting through the leaf litter of the local forests, scientists Prof. Suresh P. Benjamin and Ms. Sasanka Ranasinghe of the National Institute of Fundamental Studies, Sri Lanka, described a total of nine goblin spider species in six genera as new to science. Two of these genera are reported for the very first time from outside Australia.

Their paper is published in the open access journal Evolutionary Systematics.

With a total of 45 species in 13 genera, the goblin spider fauna in Sri Lanka – a country taking up merely 65,610 km2 – is already remarkably abundant. Moreover, apart from their diversity, these spiders amaze with their extreme endemism. While some of the six-eyed goblins can only be found at a few sites, other species can be seen nowhere outside a single forest patch.

“Being short-range endemics with very restricted distributions, these species may prove to be very important when it comes to monitoring the effects of climate change and other threats for the forest habitats in Sri Lanka,” explain the researchers.

In European folklore, goblins and brownies are known as closely related small and often mischievous fairy-like creatures, which live in human homes and even do chores while the family is asleep, since they avoid being seen. In exchange, they expect from their ‘hosts’ to leave food for them.

Similarly, at size of a few millimetres, goblin spiders are extremely tough to notice on the forest floors they call home. Further, taking into consideration the anthropogenic factors affecting their habitat, the arachnids also turn out to be heavily dependent on humans.

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Original source:

Ranasinghe UGSL, Benjamin SP (2018) Taxonomic descriptions of nine new species of the goblin spider genera CavisternumGrymeusIschnothyreusOpopaeaPelicinus and Silhouettella (Araneae, Oonopidae) from Sri Lanka. Evolutionary Systematics 2: 65-80. https://doi.org/10.3897/evolsyst.2.25200

 

 

Seven new spider species from Brazil named after 7 famous fictional spider characters

Several literary classics from the fantasy genre are further immortalised and linked together thanks to a Brazilian research team who named seven new spiders after them.

Spider characters from A Song of Ice and Fire, Harry Potter, The Lord of the Rings, The Silmarillion, H. P. Lovecraft’s The Call of Cthulhu and the children’s favourite Charlotte’s Web and Little Miss Spider each gave a name to a new small cave-dwelling six-eyed spider inhabiting northern Brazil.

Discovered in iron caves across the state of Pará, northern Brazil, the new species belong to the same Neotropical genus Ochyrocera. They are described in a new research article published in the open access journal ZooKeys by Dr Antonio Brescovit, Dr Igor Cizauskas and Leandro Mota – all affiliated with Instituto Butantan, Sao Paulo.

Interestingly, while all seven previously unknown species prefer staying in the shadows underground, none of them has the adaptations characteristic for exclusively cave-dwelling organisms, such as loss of pigmentation and reduced or missing eyes. They are classified as edaphic troglophile species, which means that they are capable of completing their life cycle away from sunlight, but are not bound to the deepest recesses. Often crawling near the surface, they can even be spotted outside the caves. To describe the species, the scientists collected about 2,000 adult specimens following a 5-year series of field collection trips.

Ochyrocera varys predating on a fly [Fig. 21 A]The list of ‘fantasy’ spiders begins with Ochyrocera varys named after Lord Varys from George R. R. Martin’s book series A Song of Ice and Fire. Lord Varys is also known as the Spider because of his manipulative skills and ability to ‘weave’ and command his networks of eyes-and-ears across two continents.

The name of Ochyrocera atlachnacha refers to the Spider God Atlach-Nacha from the universe created by H. P. Lovecraft. Atlach-Nacha is a giant spider with a human-like face which lives in the caves beneath a mountain and spins a web believed to link the world with the Dreamlands.

Two species are named after spider characters from the classic works by J. R. R. Tolkien. Ochyrocera laracna is a species named after the well-known giant spider Laracna (Shelob in English) who attacks main characters Frodo and Sam on their way to Mordor in The Lord of the Rings’ second volume – The Two Towers.

On the other hand, the Brazilian spider’s sibling – Ochyrocera ungoliant – is linked to Laracna’s mother. Ungoliant appears in Tolkien’s book The Silmarillion, whose events take place prior to those of The Lord of the Rings’ second volume The Two Towers. According to the story, Ungoliant translates to Dark Spider in Elvish.

Another staple in the 20th-century fantasy literature, the Harry Potter series, written by J. K. Rowling, also enjoys the attention of the researchers. The species Ochyrocera aragogue is an explicit reference to the talking Aragog, who lives in the dark recesses of the Forbidden Forest. In the second volume of the series, Harry Potter and the Chamber of Secrets, he confronts Harry Potter and Ron Weasley.

The authors do not fail to pay tribute to much less violent spiders known from popular children books. David Kirk’s Little Miss Spider inspires the name of Ochyrocera misspider. The character is remembered with her words: “We have to be good to bugs; all bugs.”A couple of Ochyrocera misspider [Fig. 21 C]

The Ochyrocera charlotte species refers to Charlotte, the spider from E. B. White’s classic Charlotte’s Web who befriends the main character – Wilbur the pig.

It is highly likely that there are many species and populations of this group of spiders yet to be discovered in the Neotropics, since the lack of previous studies in the region. However, the area and its biodiversity are impacted by mining.

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Original source:

Brescovit AD, Cizauskas I, Mota LP (2018) Seven new species of the spider genus Ochyrocera from caves in Floresta Nacional de Carajás, PA, Brazil (Araneae, Ochyroceratidae). ZooKeys 726: 87-130. https://doi.org/10.3897/zookeys.726.19778

Bird spiders detectives: The solution to a 200-year-old hairy mystery

Three species and three genera of birdeater spiders are described as new to science in a paper recently published in the open access journal ZooKeys. In their study, the Brazilian spider experts, Drs. Caroline Fukushima and Rogério Bertani, Laboratory of Ecology and Evolution, Instituto Butantan, report the diversity of the oldest tarantula genus (Avicularia), whose name derives from a famous 18th-century illustration depicting a bird caught by a spider.

FIG 2Even though these harmless tarantulas have long been a favourite exotic pet around the world, their identity has remained problematic ever since the first species was described back in 1758 by the “father of modern taxonomy”, Carl Linnaeus.

“He described the species based on a hodgepodge of spiders,” explain the authors. “Over the next centuries, other species with completely different characteristics were called Avicularia creating a huge mess.” As a result, basic questions, such as the characteristic traits of the genus, the number of its species and their localities, have been left unanswered.

To address the confusion, the team studied both newly collected specimens and also specimens from around the world which had previously been deposited in museum collections. Thus, they concluded that, instead of the 49 species previously assigned to the problematic genus, there are in fact only 12, including three new to science.

One of the new species, Avicularia merianae, is named after Maria Sybilla Merian (1647-1717), a pioneering scientist and a remarkable artist who made the famous illustration of a spider eating a bird. In fact, it was her work that gave birth to the popular name used for a whole group of spiders, also known as birdeaters or bird spiders.

Meanwhile, the name of the new genus Ybyrapora, which occurs in the Brazilian Atlantic rainforest, translates to “those that live in trees” from the indigenous local language Tupi. It refers to the arboreal habitat of these species. The other two tarantula genera live exclusively on the Caribbean Islands.

FIG 3“People think all biologists are like Indiana Jones, with their daily lives full of adventures in the wild. But most of the time, they are much more like Sherlock Holmes – sitting on a chair, collecting and analysing clues (specimens and scientific papers) and then using logical reasoning to solve Nature’s mysteries,” comments Dr. Caroline Fukushima.

“We, taxonomists, are ‘wildlife detectives’ who play an essential role not only in biology and conservation. Our work can also become the grounds for new technologies, medicines and ideas that could solve a variety of problems,” she adds.

“We are delighted to have finally closed one of the oldest unsolved cases,” the authors conclude.

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Original source:

Fukushima CS, Bertani R (2017) Taxonomic revision and cladistic analysis of Avicularia Lamarck, 1818 (Araneae, Theraphosidae, Aviculariinae) with description of three new aviculariine genera. ZooKeys 659: 1-185. https://doi.org/10.3897/zookeys.659.10717

Family of scaffold web spiders increased with ~20% following discovery of 43 new species

Recent study into spider specimens collected from across China, Indonesia, Philippines, Singapore, Thailand, Vietnam and Madagascar over the past 15 years, revealed the striking number of 43 scaffold web spiders that have stayed hidden from science until now. By describing the new species in a paper published in the open access journal ZooKeys, scientists from Sichuan University and the Chinese Academy of Sciences increase the number of a scaffold web spider family (Nesticidae), known from around the world, with about twenty percents.

The studied family of scaffold web spiders is a relatively small group of arachnids, which can be found at almost any locality, apart from Siberia, Central Asia, Northern and Southern Africa and places at high latitude. Prior to the study of Drs Yucheng Lin, Francesco Ballarin and Shuqiang Li, the species counted 245 in total, 12 of which are extinct and known from fossils only. A curious peculiarity in these spiders is their comb of serrated bristles, located on their rear legs, used to pull silk bands for their webs.

Although large-scale taxonomic surveys of scaffold web spiders have long remained scarce, recently the interest towards spider research in China and Southeast Asia has seen a significant rise. Thus, over the last 15 years, Chinese, American and European arachnologists have carried out several surveys, ending up with precious samples. As a result, Dr Yucheng Lin and his team followed with deeper morphological and molecular studies to discover remarkable diversity.

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In their work, the researchers have also established a new genus (Speleoticus) for five previously known, but misplaced species, which spend a lot of their time taking shelter in caves.

The majority of scaffold web spiders occur in temperate areas of the Holarctic realm, where the species tend to be medium-sized, long-legged, and prefer cave-like environments. The species found in the tropical and subtropical areas are, on the other hand, usually smaller, with shorter legs, and can be quite often spotted outside, where they crawl in forest litter, on grass, and under stones.

 

Original source:

Lin Y, Ballarin F, Li S (2016) A survey of the spider family Nesticidae (Arachnida, Araneae) in Asia and Madagascar, with the description of forty-three new species. ZooKeys 627: 1-168. https://doi.org/10.3897/zookeys.627.8629

A hair’s breadth away: New tarantula species and genus honors Gabriel García Márquez

With its extraordinary defensive hairs, a Colombian tarantula proved itself as not only a new species, but also a new genus. It is hypothesised that the new spider is the first in its subfamily to use its stinging hairs in direct attack instead of ‘kicking’ them into the enemy.

Described in the open access journal ZooKeys by an international research team, led by Carlos Perafán, University of the Republic, Uruguay, the name of the new spider genus honours an indigenous people from the Caribbean coast region, whose language and culture are, unfortunately, at serious risk of extinction. Meanwhile, its species’ name pays tribute to renowned Colombian author and Nobel laureate for his novel ‘One Hundred Years of Solitude’ Gabriel García Márquez.male kankuamo

The new tarantula, formally called Kankuamo marquezi, was discovered in Sierra Nevada de Santa Marta, Colombia. When examined, the arachnid showed something extraordinary about its defensive hairs and its genitalia. The hairs were noted to form a small oval patch of lance-shaped barbs, hypothesised by the scientists to have evolved to defend their owners by direct contact.

On the other hand, when defending against their aggressors, the rest of the tarantulas in this subfamily need to first face the offender and then vigorously rub their hind legs against their stomachs. Aimed and shot at the enemy, a ball of stinging hairs can cause fatal injuries to small mammals when landed into their mucous membrane (the layer that covers the cavities and shrouds the internal organs in the body). Once thrown, the hairs leave a bald spot on the tarantula’s belly.

“This new finding is a great contribution to the knowledge of the arachnids in Colombia and a sign of how much remains to be discovered,” point out he authors.

Figure 8“The morphological characteristics present on Kankuamo marquezi open the discussion about the phylogenetics relationship between subfamilies of Theraphosidae tarantulas and the evolutionary pressures that gave rise to the urticating hairs.”

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Original source:

Perafán C, Galvis W, Gutiérrez M, Pérez-Miles F (2016) Kankuamo, a new theraphosid genus from Colombia (Araneae, Mygalomorphae), with a new type of urticating setae and divergent male genitalia. ZooKeys 601: 89-109. doi: 10.3897/zookeys.601.7704