Arachnews: January 13, 2020
Your weekly digest of arachnid art, news, and science.
Published in
10 min readJan 13, 2020
In this week’s Arachnews: spider/human jam sessions, the European spider of the year, arthropods in the Australian bushfires, tracking ticks, name changes and newly described species, and more.
Words in bold are defined in the glossary at the end of the article.
Art & Media
- Berlin-based artist Tomás Saraceno has designed instruments that use piezoelectric elements, laser vibrometers, and other sensors to turn spiderweb vibrations into sounds we can hear—and jam along to. Vice covered his Arachnid Orchestra. Jam Sessions several years ago (you can listen to it here). A chapter of a recently released book on biotremology describes his projects in more detail. [Paper] [Sci-Hub (pp. 485–509)]
Education & Outreach
- A Telamonia dimidiata jumping spider speared by a well-camouflaged owlfly larva in Cambodia was a recent iNaturalist Observation of the Week! Learn more about both species in the linked blog post.
- Tommy Leung’s year-end roundup for Parasite of the Day features a couple of arachnid-related posts: seal nose mites and a parasitic wasp that specializes in a particular cobweb spider.
- Dolomedes fimbriatus, commonly known as the raft spider or bordered bank spider, has been chosen as European spider of the year by arachnologists across the continent. A formidable hunter and devoted parent, its habitat is increasingly threatened by human development.
Events & News
- Arthropocalpyse: In response to alarming declines in terrestrial arthropod abundance and diversity, group of scientists from around the world have proposed a roadmap for insect* conservation and recovery. In the short term, they recommend “no-regret” solutions like reducing pollution, finding eco-friendly replacements for pesticides, and changing the way we farm. [Nature Ecology & Evolution]
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* not just insects, we know, we know - Australian wildfires: The destructive fires raging across Australia, exacerbated by the drought and heat caused by a changing climate, threaten not only koalas and kangaroos but also countless invertebrates—less charismatic, but equally valuable. For the New York Times, Helen Sullivan interviews three scientists about the creatures they study, including Dr. Leanda Mason, who is deeply concerned about the trapdoor spiders of the Stirling Ranges. [New York Times] [Archive]
- Big spiders wanted! Scientists at the University of Queensland are asking the people of Brisbane for large spiders to use in venom research. The search has already yielded several spiders.
- Call for abstracts: Entomology 2020, the Entomological Society of America’s annual meeting, takes place in Orlando, Florida this November, and there are three mite- and tick-related symposia planned. Submissions are due February 21.
Research
- Roses are red,
Colombia is a nation,
This Hibana ghost spider
was eaten by a crustacean. [Paper 🔓️]
Sex
- Are female raft spiders (Dolomedes fimbriatus) less likely to cannibalize their mates if there’s fewer males around? Contrary to previous reports, the females rarely attacked males and didn’t eat any of them; and the number of males they met had nothing to do with whether they attacked. Males, however, put in less effort if they had already encountered lots of females. [Paper]
- What does Lustrochernes pseudoscorpion mating look like? It’s an elaborate process involving holding each other’s claws, rubbing legs, and a behaviour not seen in other species — the female actively sitting on top of the spermatophore to transfer its sperm. [Paper 🔓️]
- Here’s how the Uruguayan wolf spider Lycosa inornata gets it on, in excruciating detail. [Paper 🔓️]
Pests & parasites
- Swiss raspberry farmers checking for Phyllocoptes gracilis gall mites can save time and effort by just sampling the upper two-thirds of the canes. [Paper]
- For Bryobia praetiosa clover mites, the ideal temperature is 22.4°C. Once you start getting over 30°C, their fertility drops. [Paper] [Sci-Hub]
- The ticks Amblyomma sculptum and Amblyomma parvum are both common in the fragmented forest of southern Brazil, but researchers found that A. parvum is way more common in clumps of spiky bromeliad plants. They have a few ideas why. [Paper] [Sci-Hub]
- The black-legged tick (Ixodes scapularis) has become established in three counties in Nebraska. [Paper] [Sci-Hub]
Physiology
- To test how heat affects the Argentinian tarantula Grammostola vachoni, researchers put tarantulas in sealed tubes, immersed the tubes for half an hour in water heated to various temperatures between 5° and 45°C, then took them out and had them sprint down a metre-long plastic tube. Above 40°C, they got markedly slower and some refused to move at all. Tarantulas normally avoid high temperatures by living in burrows and only going out at night. But as we’re already seeing in Australia, climate change brings extreme conditions spiders are unable to avoid. [Paper] [Sci-Hub]
- A thesis on chemicals in the nervous systems of spiders and scorpions. One of its findings: scorpions produce and use norepinephrine, previously thought to be confined to vertebrates. [Paper 🔓️]
- What are the trichobothria, or sensory hairs, on scorpions’ pedipalps for? Probably not capturing prey, since scorpions with their trichobothria removed were just as good at catching crickets.
- It’s still a mystery how amblypygids find their way back home after their nightly wanderings. This study rules out magnetic fields. [Paper] [Sci-Hub]
Miscellaneous
- A comparison of the webs of the mesh-web weavers Emblyna and Mallos hesperius, who weave flat webs over the top of small concave leaves. [Paper]
- Yet another paper on mineralizing spider silk with hydroxyapatite nano-crystals. This would be particularly useful for regrowing bone. (Last week’s Arachnews featured something very similar.) [Paper] [Sci-Hub]
- Populations of soil mites living at high altitudes in the Darjeeling Botanic Garden fluctuate throughout the year, peaking during cold, dry periods. [Paper] [Sci-Hub]
Taxonomy
Americas
- This beast of a paper (it’s 176 pages!) analyzes the phylogeny of Wagneriana, a genus of spiders found in tropical regions of the Americas. Along the way, the authors consider various ways of constructing spider “family trees” and how to weight different kinds of data. They also add a new genus, Popperaneus, named after philosopher of science Karl Popper. [Paper] [Sci-Hub]
- In an impressive team effort, researchers dug into 130 years of literature to create a dataset of South American ticks, along with relevant information like their hosts, their geographic location, and environmental factors. [Paper 🔓️]
- A look at the Ixodes ricinus species complex in South America. [Paper] [Sci-Hub]
- Related: untangling Ixodes fuscipes, I. spinosus, and I. aragaoi. The loser is I. aragaoi, determined to have been I. fuscipes all along. [Paper] [Sci-Hub]
- The tarantula Holothele longipes is found across much of Central and South America, so it’s not a surprise that it’s also found in Guyana and Panama. [Paper] [Tarantupedia]
- The name Linga was taken (by a mollusc), so this linyphiid genus from the Falkland Islands is now called Notolinga. [Paper]
- The 19th century nobleman and scientist Charles Walckenaer, who classified a lot of species for the first time, based a lot of his descriptions of New World spiders on drawings by the American naturalist John Abbot. But which drawings? There’s several different versions floating around, all with slightly different numbering. It turns out that Walckenaer was using a different copy than everyone thought! This explains some discrepancies in his work. It also means taxonomists will have to go back and correct the “changelogs” for various species — we’re not sure how many yet. [Paper 🔓️]
Africa
- The pioneering late 19th–early 20th century arachnologists George and Elizabeth Peckham made many contributions to the study of jumping spiders, but “recording where exactly in Madagascar they found their specimens of ant-mimic jumping spiders” was not one of them. A new paper redescribes Myrmarachne augusta with more detailed information. [Paper]
Europe
Arachnology, the British Arachnological Society journal, recently published its 50th anniversary issue. There’s several papers looking back on the last half-century:
- A revised checklist of the spiders of Great Britain and Ireland. [Paper]
- A review of British pseudoscorpions notes that in the digital age “the interest in pseudoscorpions has subsequently blossomed and given rise to a Facebook page and a number of identification courses”. You love to see it. [Paper]
- An updated checklist of British harvies. Several new species have been added in the last 50 years, most likely new arrivals rather than overlooked native species. [Paper]
- Mitochondrial genomes are key for figuring out how different kinds of ticks are related, and the more we have, the clearer our picture is. The latest to be sequenced is the ornate sheep tick (Dermacentor marginatus) from a specimen from Slovakia. [Paper] [Sci-Hub]
Asia
- Neotetranychus spider mites found for the first time in Saudi Arabia. [Paper 🔓️]
- Researchers confirm that the mites in the eriophyid genus Diptilomiopus (found widely around the world but mostly in Asia), who often cause rust, galls, and other deformities on fruit trees, are all descended from a common ancestor. [Paper] [Sci-Hub]
- Proctolaelaps sibiriensis is a mite that rides around on honeybees in Siberia! Here’s a new description, and also a guide to identifying other bumblebee-riding Proctolaelaps. As we recently learned from Dr. Catherine Scott, the genus name means “anus hurricane” and probably refers to their large anal openings. Doesn’t this fact just enrich your life? [Paper 🔓️]
- A new genus of spiders, Vappolotes, in the agelenid subfamily Coelotinae, found in Guizhou, China. “Vappo” is apparently “a variety of nocturnal moth”, and “refers both to the spiders being collected from the dark zone of a cave and to the copulatory ducts in the females which are shaped like the wings of a moth.” Poetic. [Paper] [Sci-Hub]
- Three new goblin spiders found in Jiangxi, China. [Paper] [Sci-Hub]
- A new species of flattie, Selenops ef, has been found in a cave in Cambodia. It’s unusual to find flatties in caves, and they’re not sure yet whether it lives there or just wandered in. Like the previously described Selenops ab, “the shortest possible name…[indicates] the small size of this new species”. Presumably the next little flattie this guy finds will be Selenops hi. [Paper]
- A new Siler jumping spider from Japan. [Paper 🔓️]
- Two new coelotine species from Japan, Coelotes isensis and Tegecoelotes kumadai. [Paper]
Oceania
- The “poorly known” crevice weaver Labahitha gibsonhilli, from the Christmas Islands, gets a better description with photos and illustrations. [Paper 🔓️]
This has been the week in arachnids. Thank you very much for reading! Corrections, suggestions, and additions are always welcome. Drop us a silk line at @arachnofiles.
Glossary
- piezo-electricity: electricity created by putting mechanical stress (so, squeezing or stretching, etc.) on an object.
- laser vibrometer: a machine that measures vibrations by shining a laser at a tiny mirror. The mirror is attached to an object (when listening to jumping spider vibrations, the object is pantyhose stretched taut over a hoop). When the object vibrates, so does the mirror, which makes the spot from the reflected laser bounce up and down. A computer translates those laser movements into sound. You can make your own at home (sans the computer part) from a laser pointer, saran wrap, a funnel or cup, a small piece from a very carefully broken mirror, and a loud speaker (or something else to make the vibrations).
- biotremology: the study of vibrations produced by organisms.
- flattie: a spider from the family Selenopidae, also called “moon-eyed spiders” because their eyes are arranged in a crescent.
- harvie: short for “harvestperson”, arachnids from the order Opiliones. Also known as “harvestmen” and “daddy-long-legs”. Note: I am literally the only one who calls them this. I’m trying to make it a thing.
- hydroxyapatite: the mineral that makes bones and teeth hard.
- mitochondria: the powerhouse of the cell.
- phylogeny: the evolutionary history or “family tree” of related species (or higher categories), reconstructed from genetic data and physical traits.
- spermatophore: a package of sperm; in the pseudoscorpion Lustrochernes, it looks like a little glass flower on a delicate stalk.
- trichobothria: long hairs that arachnids use as sensory organs.
