Arachnews: April 20, 2020
Your weekly round-up of news, art, and science about our arachnid friends.
This week: springtime wolf spiders; researchers in lockdown; medical benefits of spider and scorpion venom IN MICE; new “family trees” for pirate spiders and jumping spiders; and more.
Terms in bold are defined in the glossary at the end.
Art & Social Media
Education & Outreach
- Spider zookeeper Caitlin Henderson is working from home…with a couple of new housemates. [YouTube]
- Wildlife YouTuber Fer Theman interviews UNAM’s Diego Barrales about arachnid outreach, science, and why “Arachno_Cosas”? And, of course, answering viewers’ questions. [YouTube]
- On the University of Cambridge Museum of Zoology blog, Michael Pashkevich writes about what makes golden orbweavers (Nephila) so cool. “Nothing moreso wakes me up during a sleepy morning of fieldwork than walking into the web of a Nephila pilipes!” [Animal Bytes]
- Joseph Schubert writes about his recent spider-hunting trip, where he tracked down and described seven new species of peacock jumping spiders with the help of citizen scientists. [The Conversation]
- Related: Schubert talks to ScienceNews’s John Pickrell about how he went from arachnophobe to arachnophile. [ScienceNews]
Events & News
- The New York Times has an obituary for “the real Spider-Man” Norman Platnick, who passed away at the age of 68 last week. [NYT]
- “When I brought the wolf spider home, one of my roommates seemed a little dismayed.” As science gets put on hold due to the coronavirus pandemic, many scientists have had to make difficult choices about how to care for their study subjects. [NPR]
- In a press release, Kraig Biocraft Laboratories announces they have developed gene editing technology that allows silkworms to create “nearly pure” spider silk. (A major challenge in producing spider silk is that spiders are not easily farmed, hence why scientists are so interested in using other organisms—e. g. goats, bacteria, and now silkworms—to produce spider silk proteins.) [Kraig Labs]
- There are quite a lot of studies on how birds learn to avoid brightly coloured, gross-tasting bugs. (Is it the colour, or the taste?) There is much less research on other keen-sighted predators, like jumping spiders. These University of Florida researchers share how they designed their experiments to work with much smaller subjects, in the hopes of getting more scientists to follow their lead. [Paper 🔓️]
- Why do some great tits (Parus major) have more ticks than others? Birds that explore more are more likely to be infested by ticks, as opposed to stay-at-home types. But the birds with the most ticks are the ones that are in worse shape and less able to fend off parasites. (“Great tit tick burden”…say that five times fast.) [Preprint 🔓️]
- Here’s a study of the kinds of spiders that live among cherry orchards in Spain. Do organic vs. conventional farming methods make a difference? There were more spiders overall in organic orchards, but the different small-scale habitats they provide are better for some spider lifestyles than others. [Paper 🔓️]
- There are many organisms that parasitize spiders, from wasps to worms to fungi. What parasites plague New Zealand’s spiders? Here’s a list of all those mentioned in the scientific literature so far, and suggestions of what might be out there that hasn’t been documented yet. *X-Files theme plays* [Paper 🔓️]
- Peptides from spider and scorpion venom make promising drugs because many of them target the Naᵥ1.7 voltage-gated ion channel, a kind of “gate” in cell membranes that transmits pain-related electrical signals. If you want to deliver a painkiller precisely where it is needed, that’s exactly what you are looking for. Researchers at the University of Queensland have modified a peptide from the venom of the Chinese tarantula Cyriopagus schmidti to make it even better at targeting Naᵥ1.7…IN MICE. [Paper] [Sci‑Hub] [Press release]
- Venoms from three scorpions (Androctonus crassicauda, Messobuthus eupeus, and Hemiscorpius lepturus) slow colon cancer tumour growth…IN MICE. (Also, they tried to determine the lethal doses for each venom, but a tiny dose of H. lepturus venom killed all the mice within a week. Do not mess with Middle Eastern scorpions.) [Paper] [Sci‑Hub]
- Who will save Brazilian agriculture from the red palm mite (Raoiella indica)? Past studies point to the predatory mite Amblyseius largoensis. There’s just one problem: no one sells it. Will the widely commercially available Neoseiulus barkeri work just as well? Experiments in the lab and in the field show it can thrive on red palm mites, but there’s still some questions to answer before it’s ready for prime time. [Paper] [Sci‑Hub]
- A recent study tested plant-based acaricides vs. chemical ones against the two-spotted spider mite (Tetranychus urticae) in the field (specifically, an apple orchard in Syria). The authors figure the plant-based acaricides, which used garlic and wheat extracts, were effective because of lectins*, plant proteins that make carbohydrates clump up. As well as helping plants store energy, lectins might protect plants against arthropod pests. [Paper 🔓️]
* They’re what makes you sick if you don’t cook your beans right. But there is no reason to avoid them generally.
- How does an orbweaver figure out where a trapped insect is in its web? The authors of this paper created an algorithm that describes how it works. This time, in two dimensions! We don’t really understand it, but there’s an intimidating amount of LaTeX, so we assume they know their stuff. [Paper] [Sci‑Hub]
- While creating karyotypes for Ctenus wandering spiders, researchers seem to have caught a couple of species in the middle of evolving extra sex chromosomes, the sneaky little bastards. Spiders tend to do this a lot, mostly when humans aren’t looking. [Paper 🔓️]
- Hoo boy. Wayne Maddison et al.’s new paper substantially revamps the branch of the jumping spider “family tree” that contains Sitticus and its close relatives. This lineage of jumping spiders arose in the tropics of the Americas, then spread to Eurasia (and some Eurasian species spread back to the Americas). The relationships between them are a subject of heated debate among experts. In this paper, many species are reclassified; for example, several spiders formerly classified as Sitticus, like the widespread S. fasciger, are renamed Attulus. There’s also bits on sitticines’ wide variety of sex chromosome systems and which sitticines are found in Canada. Yay CanCon. [Paper 🔓️]
- Pirate spiders (family Mimetidae) are spiky-legged spider-eating spiders who use mimicry to draw in their prey; they’re found all over the world. A new “family tree” using both genetic analysis and physical characteristics brings several changes. The genera Phoebetinus and Reo get moved to the genus Mimetus. Mimetus itself is probably multiple distinct lineages that will have to be sorted out at some point. Also, pirate spiders’ closest relatives are the long-jawed orbweavers (family Tetragnathidae) and the weird little family Arkyidae. [Paper] [Sci‑Hub]
- A whopping twenty-one new species of Mysmenopsis spiders from Ecuador. Mysmenopsid spiders are kleptoparasites—they hang out in other spiders’ webs and steal bits of prey. [Paper] [Sci‑Hub]
- Brazil has fifty species of recluse spiders (Loxosceles) that form several different lineages. Their chromosomes are a lot less variable than the jumping spiders’ we just talked about, but still have slight differences. Based on their similarities, the amazonica and gaucho groups are closely related. [Paper]
- A new species of running crab spider, Berlandia zabele, found in Piauí, Brazil. It is named after a character from local Indigenous mythology: “Zabelê, a member of the Amanajós tribe, fell in love with Metara, a member of an enemy tribe. When the romance of Zabelê and Metara was discovered, tribal warfare resulted in the death of both lovers. The god Tupã pitied the two lovers and so transformed them into birds that fly together for eternity.” [Paper 🔓️]
- A new checklist of Serbian pseudoscorpions includes 76 species across four families. (There’s also a brief summary of the history of pseudoscorpion research in the Balkans.) [Paper 🔓️]
- Two new Pseudoblothrus pseudoscorpion species found in caves in the Crimean mountains. [Paper 🔓️]
- A new species of ground spider, Civizelotes aituar, found in the steppes of the Urals, Russia. [Paper 🔓️]
- A new species of ant-mimicking jumping spider, Belippo eburnensis, has been described from Côte d’Ivoire. Its name comes from the Latin for “Ivory Coast”, Litus Eburneum. [Paper 🔓️]
- A new checklist of spiders of South Africa’s Addo Elephant National Park, based on observations made over the last 50 years, includes over 270 species belonging to 47 families. [Paper 🔓️]
- The corinnid Creugas gulosus is found around the world and has been described under many different names over the years. Here’s an up-to-date description based on specimens found across Africa and the Seychelles. [Paper 🔓️]
- A new Salticus jumping spider from Turkmenistan, S. karakumensis (after the Karakum Desert, where it was collected). [Paper 🔓️]
- Three new species of Segestria tube-web spiders were found in crevices in stony cliffs in Kazakhstan and Tajikistan. By night! Sounds fun. [Paper] [Sci‑Hub]
- Well above the Arctic Circle, at the mouth of the Yenisey River, is an island called Sibiryakova. “There is no frost-free period. The soils are subsoil-frozen tundra-sandy, subsoil-frozen tundra-boggy and oozy, always weak in thickness…” This desolate place still boasts thirteen species of linyphiid spiders! [Paper 🔓️]
- Related: two obscure Arctic linyphiid spiders in the genus Hilaira get updated descriptions. [Paper 🔓️]
- Portia albimana reported in the state of Karnataka, India for the first time. The little jumper was found under a log, sheltering in the web of a curtain-web spider. Always flip logs, people, you never know what you’ll find. [Paper 🔓️]
- Three new Carrhotus jumping spiders described from across north-east India. The authors also think some jumping spiders from other genera are really misclassified Carrhotus species. [Paper 🔓️]
- Two new Oedothorax linyphiid spiders from Meghalaya, north-east India. [Paper 🔓️]
- An almost 300-million-year-old Eoscorpius fossil has been found in a coal bed, once a peat swamp, in Inner Mongolia, China. The tiny specimen is only the third fossil scorpion found in China. Based on the way the limbs are positioned, the authors believe it may be the remains of a cast-off exoskeleton. [Paper] [Sci‑Hub]
- The orbweaver Aculepeira matsudae has been found in Primorskiy Kray in the far east of Russia, just across the sea from Hokkaido, Japan, where it was first found. [Paper 🔓️]
- I screamed when I saw this very ｆｌａｔｔｅ spider, one of several jumping spiders recently found in Thailand for the first time. The others are cute too, though. [Paper 🔓️]
- A new species of palp-footed spider, Boagrius simoni, found in Borneo. [Paper 🔓️]
- acaricide: a pesticide for mites and/or ticks.
- karyotype: a chart that shows the size and shape of each set of chromosomes an organism has.
- kleptoparasite: an animal that eats by stealing other animals’ food. Many spiders are kleptoparasites of other spider species.
- peptide: a molecule made of a bunch of amino acids strung together. A bunch of peptides strung together is a protein.
- voltage-gated ion channel: a large protein that acts as a kind of “gate” in a cell membrane, letting ios (electrically charged molecules like sodium, potassium, and calcium) in and out. The gate can be shut, allowing these ions to build up on one side. Once there’s a big enough difference in electric charge (voltage) between the two sides of the membrane, the gate quickly swings open. This releases a flood of ions to the other side, creating an electrical current that can be transmitted very quickly between cells. The many types of voltage-gated ion channels are important parts of nerve and muscle cells.