Arachnews: February 10, 2020
The latest in spiders, scorpions, ticks, mites, and more.
Published in
17 min readFeb 10, 2020
This week: whip spider mating, some good and not-so-good SciComm, mainstream media coverage of #PruittData, medical uses for scorpion and spider venom, some very pretty tarantulas, and more.
Terms in bold are defined in the glossary at the end of the post!
Art & Social Media
Behavioral ecologists are tasked with the nigh impossible: to read the inscrutable expressions of creatures whose lives are so wonderfully unlike ours. I can’t pump hydraulic pressure into my legs and spring nimbly from one blade of grass to another. I can’t see approaching grasshoppers through three different kinds of eyes. I don’t have to look out for hungry birds or larger spiders. But my subjects do. They can tell me their story if I give them the means, then step back and watch without leaping to conclusions. As faithful interpreter, my job is to quell my human sensibilities and describe their experience honestly without translating it into my own.
- “This piece is in response to #PruittData,” writes Sarah Jean McPeek. “I wanted to try to convey what makes the work of behavioral ecology…so difficult, so fascinating, and so rewarding.” [Lively Discussions]
Education & Outreach
- Former arachnophobes turned tarantula owners are more common than you might think! The BBC has a video featuring Vanessa Woods (@vanessastarantulas on Instagram), who started watching tarantula videos on YouTube to get over her fear and ended up with a few dozen spiders of her own. [BBC]
- Animal Planet’s Little Giants features an amblypygid. I have…mixed feelings.
• Cons: plays up the “scary” and “deadly” aspects of a timid creature that is harmless to humans; amblypygids don’t have acid on their pedipalps (what? were they thinking of vinegaroons’ spray or just making stuff up?); uses imperial instead of metric units.
• Pros: shows simple ways to measure things like its range of movement, speed, and grip strength; visualizes what that would look like at human scale for easy-to-understand analogies. [YouTube] - A recent Nature Notes column in the Ballarat Courier features the well-known redback spider (Latrodectus hasselti); simple, non-sensational redback basics. [The Courier]
- This journal article describes practical and effective ways to manage house dust mites, which some people are allergic to. [Acarological Studies 🔓️]
Events & News
#PruittData
The story so far: an anonymous tip led to the discovery of widespread data irregularities in the work of Jonathan Pruitt, a hyper-prolific behavioural ecologist specializing in social spiders. Since last week, several more papers have been retracted, with more to come. Here’s a spreadsheet keeping track of things; apparently there is also a Slack.
Coverage from high-profile outlets:
- “It was through his scholarly output that Dr. Pruitt became one of 24 top academics recruited to come to Canada from institutions in the United States and elsewhere as part of the federal government’s Canada 150 celebrations.” The Globe and Mail covers #PruittData and reports that McMaster University is investigating. [Globe and Mail] [Archive]
- Kate Laskowski is interviewed on CBC Radio’s As It Happens. Segment begins at 52:20. [CBC Radio]
- In Nature’s coverage, people are starting to drop F-bombs: “fabrication” and “fraud”. They report that the count of papers with questionable data is currently at 17. [Nature]
There are also many ongoing discussions worth following; summarizing everything going on on Twitter is beyond me, but here are notable longer-form posts.
- Joan Strassmann argues that, going forward, the best option is “to simply trust your collaborators,” but “no important idea should be validated by work from just one lab or one set of collaborators”. [Sociobiology]
- An anonymous blogger has some thoughtful points about the limitations of data transparency. “The idea that researchers need to have some grounded experience with the data production and the organisms they are investigating often conflicts with the proposed solutions offered by strong advocates of open data, who believe that transparency alone may be enough.” They also emphasize that “no data is ever ‘raw’”; it is always produced by, and designed to be legible to, human judgment. [Lifecycles]
- Alexandra McInturf, a PhD student in UC Davis’s Animal Behaviour Graduate Group, reflects on the fallout and what it means for researchers just beginning their careers. “As I try to make a name for myself, the culture of academia can make it difficult to balance how I spend that time: producing papers quickly, or double- and triple-checking every number.” [The Ethogram]
- Wayne Maddison, a long time spider scientist, also speaks to those affected: “To those injured by this collapse of trust: Your honest and sincere efforts to understand nature are appreciated; they are contributions regardless of the fate of the papers. You should not blame yourself for not having noticed the flaws in data handed to you by a respected scientist.” [Reflections on a Spider’s Eyes]
- Andrew Hendry has opened the floor for a series of guest posts about trust and data integrity. [Eco Evo Evo Eco]
- Adam Hasik argues that the obscurity of Pruitt’s study organisms allowed for data anomalies to go overlooked. “To put into perspective how unknown the the spider system is: when I broke down Pruitt’s paper (which is currently under investigation for data manipulation) for our Paper of the Week a year and a half ago I was unable to find a common name for the spider involved in the study [Stegodyphus dumicola].” [Ecology for the Masses]
- Kate Laskowski has updated her original blog post with an explanation of how she did not spot problematic data sooner. “I looked through the raw datra, looking for obvious input errors and missing values. But in datasets with this many numbers most exploration has to be graphical.” [Laskowski Lab]
Miscellaneous
- The Australian Reptile Park gets its biggest funnel-web spider yet, a beefy Newcastle lad named Dwayne “The Rock” Johnson. “Keepers are eager to find out the suburb in which it came from with hopes of finding more of the large spiders as they produce larger amounts of venom.” [News.com.au]
- A new interpretive installation about the ladybird spider (Eresus sandaliatus) launches this Saturday, February 15 in Dorset, UK. It’s part of Back from the Brink’s project to rebuild populations of the endangered spider. [Back from the Brink]
Update: due to weather conditions, the event is cancelled.
Research
Medicine
- Recluse spiders (Loxosceles), as well as their cousins in genus Sicarius, are famous for their dermonecrotic (skin-killing) venom. But their venom can also act as an anticoagulant; it breaks apart the proteins that cause blood to clot. Turns out that existing antivenom doesn’t prevent this at all, which is a) a bummer, but b) really interesting and cool. [Paper 🔓️]
- Amyloid-β (beta) peptides are molecules that make up proteins that really like aggregating (clumping together) into tough, solid fibres and sheets. These form inside the brains of people with Alzheimer’s, for example. To study the aggregation process, you need to make lots of Aβ peptides, and they have to be very pure, because any contamination or residue affects the way they stick together. Hey, you know who makes proteins made of Aβ peptides that can be stored in highly concentrated liquid form and then quickly turned into fibres and sheets? Spiders! These researchers customized bits of golden silk orbweaver spidroin (spider silk protein) to produce lots of nice clean Aβ peptides. [Paper 🔓️]
- A toxin from the venom of the Brazilian scorpion Tityus bahiensis causes seizures (IN RATS) by messing with the machinery that transports sodium ions in and out of brain cells, causing an overload of the neurotransmitter glutamate. [Paper 🔓️]
- More fun with scorpion venom and ion channels! A certain toxin in scorpion venom can be mutated so it only blocks a particular channel that is involved in keeping certain types of cells going, like immune cells and cancerous tumour cells. [Paper] [Sci‑Hub]
- This Master’s thesis investigates how Brazilian wandering spider (Phoneutria nigriventer) venom affects invasive brain tumour cells. [Paper (in Spanish) 🔓️]
- A vaccine…against scorpion stings? Try it IN MICE. Mice injected with biodegradable nanoparticles filled with a toxin from scorpion venom were later able to withstand up to eight times the median lethal dose of venom. [Paper] [Sci‑Hub]
Technology
- In high-elevation areas where fresh water is hard to come by, one way to collect water is fog harvesting — using fine mesh to pull moisture out of the air. A recent Master’s thesis proposes a more efficient fog collector design inspired by spider silk. [Paper 🔓️]
- Life pro tip: shed tarantula skins are good at soaking up crude oil spills. [Paper] [Sci‑Hub]
- Is there any technology that can’t be improved with spider silk? Making carbon fibre, apparently. [Paper] [Sci‑Hub]
Agriculture
- The cotton boll weevil (Anthonomous grandis) is a widespread cotton pest. Several of these weevils collected from fallen cotton in an experimental field were found to be crawling with mites (Proctolaelaps bickleyi). Are the mites just hitching a ride? How detrimental are they to the weevils? We’re not sure yet, but it’s worth looking into. [Paper] [Sci‑Hub]
- Brown marmorated stink bugs (Halyomorpha halys) are invasive, obnoxiously ubiquitous agricultural pests. They’re basically the Minions of invasive species. Other arthropods do prey on them, but exactly which ones depends on the crop and location. A study of predators in Minnesota apple orchards turned up lots of spiders, particularly orbweavers, jumping spiders, and sheet-web weavers. However, they’re not really making a dent in brown marmorated stink bug populations. Obviously, we need more spiders. MORE! [Paper] [Sci‑Hub]
- Want to reduce pesky planthoppers and leafhoppers in your rice paddies? Instead of pesticides, try mulching and leaving old plants in the field. The decomposing plant material provides food for aquatic gnat and midge larvae. The adult gnats and midges become food for spiders, an “energy subsidy” that gets them to stick around and eat pests as well. [Paper 🔓️]
- Four different spider species — orchard orbweavers (Leucauge venusta), wolf spiders (Lycosa pseudoannulata), furrow orbweavers (Larinioides cornutus), and long-jawed orbweavers (Tetragnatha shikokiana) — were pitted against each other in a whitefly-eating contest. The wolf spiders won in the lab, but in the greenhouse the orchard orbweavers came out on top. Winners get a lifetime supply of whiteflies. [Paper 🔓️]
- How do two species of minute pirate bugs (Orius) rate as biological pest control? O. laevigatus generally eats more spider mite eggs than O. vicinus, except with, for some reason, servings of 2 and 32 eggs. [Paper 🔓️]
- Biomite is a plant-based, “natural” acaricide. However, it kills off the beneficial predatory mite Neoseiulus californicus, which is often used to control the two-spotted spider mite Tetranychus urticae.
Parasitism
- Geckobiella mites and Amblyomma ticks are both common parasites of iguanas, but weren’t known to interact with each other. In Panama, researchers found Geckobiella mites laying eggs on the ticks! Are they hitching a ride, or is this a rare kind of hyperparasitism? All we know right now is that it’s very cool. [Paper 🔓️]
- A cattle tick found on a Panaman jaguar suggests the cat was in a pasture at some point — passing through, or maybe hunting livestock. [Paper 🔓️]
- Check out these deformed Dermacentor dissimilis ticks found on horses and cows from Nicaragua. Sadly, we don’t know enough about these ticks to offer much of an explanation. [Paper 🔓️]
- Ticks can carry combinations of multiple pathogens, but it’s not random. A study of black-legged ticks (Ixodes scapularis) in Connecticut found that nymphs carrying Babesia microti were more likely to also have Borrelia burgdorferi, while adults with Anaplasma phagocytophilum were more likely to be infected with B. burgdorferi. [Paper]
- Mites live anywhere and everywhere — seal noses, plant pores, and even in bird quills! And now we know how many mites live in Canadian ovenbirds’ wing feathers. (A lot more than in their tails.) [Paper]
- Adding woodchip “buffer zones” around wooded areas in Ottawa parks is a simple way to reduce the number of questing black-legged ticks along recreational trails. That means less opportunities for humans to possibly contract Lyme disease. I’m so hyped about this paper, ngl. Arachnology! Public health! Municipal policy! Doesn’t that get you all fired up?! Just me? Okay… [Paper 🔓️]
Miscellaneous
- Have you ever wondered why arboreal tarantulas are so bright and colourful? Doesn’t it make them stand out to predators? Well, maybe not! Read up on the lives of Brazilian tarantulas Typhochlaena costae and T. seladonia, who make trapdoor nests on specific trees. (If you sign up for a World Spider Catalog account, you can download the PDF.) [Paper]
- Colonies of Anelosimus eximius social spiders in Colombia seem to pass down collective behaviours, like their level of aggressiveness when foraging, to offshoot colonies. Now, I know you’re like, is this a Pruitt paper? and, well, it’s not not a Pruitt paper. Lead author David N. Fisher, summarizing the paper in a Twitter thread, says “the last author was not involved in data collection, curation, or analysis…they were involved in the design of the study and the writing. Their input was therefore substantial; without them the paper would not have happened.” Good to know. [Paper] [Sci‑Hub] [Data ✨️]
- New frontiers in ethically questionable social spider research: algorithms based on social spider behaviour can be used to coordinate teams of attacking drones. [Paper 🔓️]
- Despite the fact that the excellent Spidentify app already exists, a group of software engineers have used machine learning to identify 10 species of Australian spiders from photos. Their program seems to work okay (but they call the spiders poisonous, which they are not). And, again, Spidentify exists. [Paper] [Spidentify]
- Vets have generally been ill-equipped to treat pet spiders…until now. A forthcoming textbook on diagnostic tests for exotic animals includes a chapter on terrestrial invertebrates, including arachnids. The limited Google Books preview includes tantalizing snippets about anesthetizing tarantulas for hemolymph samples, as well as examples of diagnostic reference levels for various tarantulas and scorpions. [Paper][Google Books]
- A lab at Germany’s Hannover Medical School breeds golden silk orbweavers (Australia’s Nephila edulis) to study the medical uses of spider silk, and they recently published a guide to how they keep their spiders. Having seen a Nephila lab in this Skype A Scientist video, I figured this was going to be more of the same. I began to suspect their facilities were somewhat unorthodox part way through the “Webs” section, where the authors mention that the spiders build webs “in room corners or near the floor under tables” and sometimes “across paths used by personnel”. In “Breeding and rearing”, they write that “all adult animals live free in one room” and that egg sacs in the smoke detectors can trigger false alarms. Oh, and “due to large amounts of food debris and spider feces on the floor, the room has to be cleaned once to twice a week by moist wiping.” Lest you worry this is some kind of anarchic spider Lord of the Flies situation, they explain that due to the plentiful food “cannibalism is significantly reduced and spiders mate all year long”. [Paper 🔓️]
- Some spider species that mimic ants aren’t just trying to fool predators—they’re also preying on ants themselves. Is the South African ant-mimic jumping spider Mexcala elegans one of them? These researchers compared different life stages of M. elegans to ants in its natural habitat and sequenced the spiders’ gut contents to identify what they were eating. They got some counterintuitive results. [Paper 🔓️]
- We’re still unravelling (heh) how fuzzy cribellate spider silk captures prey. The capture silk of the Taiwanese lace-sheet spider Psechrus clavis is made up of a main (axial) fibre with another thread coiled around it like a spring, encased in a fuzz of back-combed nanofibres. These researchers found that as the silk stretches, the axial fibre can break in multiple places, but the coiled fibre picks up the slack. They liken it to rebar reinforcing concrete. [Paper] [Sci‑Hub]
Taxonomy
Big Picture
- Sometimes specimens identified as different species turn out to be different life stages or sexes of the same species. This might be the case with the 300-million-year-old horseshoe crabs classified as Bellinurus and Euproops. A recent paper carefully examines the fossil record—and to make it even clearer for readers, includes 3D images for more detail. Grab some red-blue 3D glasses and read along! Why don’t more papers have this?! [Paper 🔓️]
- This paper came out back in December; I somehow missed it, and it’s too important not to include. It’s a comprehensive “family tree” of mygalomorphs (the group of spider families that includes tarantulas, funnel-web spiders, and trapdoor spiders), using genetic analysis. It proposes a lot of big classification changes—nine new families! The whole thing is well worth a read; they describe what traits are likely “handed down” from common ancestors, when and where different lineages diverged, and more. [Paper] [Sci‑Hub]
- The Sharma lab’s latest phylogenetic study reconstructs the “family tree” of sea spiders (pycnogonids), bizarre leggy marine creatures that are a sister group to arachnids. [Preprint 🔓️]
- Millions of years ago, the chunk of land that would become India broke away from the supercontinent Gondwana, sailed north, and smashed into Eurasia, creating the Himalayas. In the wake of this continental collision, many species from India migrated to southeast Asia. But why southeast Asia and not, say, east or central Asia? Retracing the history of the Ochyroceratidae spider family offers clues. [Paper] [Sci‑Hub]
Americas
- Meet Taito adrik. This charming Peruvian harvestperson with a butterfly-like marking on its back is named after Brazil’s Museu Nacional arachnid curator, who “lost most of his invaluable collections and fruits of his many field trips through the fire catastrophe in September 2018”. [Paper 🔓️]
- The Gulf Coast tick (Amblyomma maculatum) has become established in Illinois, bringing with it an exciting new flavour of rickettsial disease. [Paper]
- Explore the evolutionary history of Kibramoa, a little-studied plectreurid spider that has lived a quiet semi-sedentary life in California for the past 15 million years or so. [Paper] [Sci‑Hub]
- A new species of pseudoscorpion, Spelaeobochica mahnerti, found in a cave in Minas Gerais, Brazil. [Paper]
- A new species of soft tick, Ornithodoros octodontus, found parasitizing degus, burrow-dwelling rodents in Chile. [Paper] [Sci‑Hub]
Europe
- Adult Hyalomma marginatum and H. rufipes ticks have been found in Sweden for the first time, probably thanks to global warming. [Paper] [Sci‑Hub]
- Looking for macrochelid mites in Hungary? Don’t forget this checklist of the 34 species that have been recorded so far. [Paper 🔓️]
Asia
- A new species of soil-dwelling zerconid mite, Prozercon miraci, found in Turkey. [Paper 🔓️]
- Trombidium mite larvae have been found parasitizing a wide variety of spiders, but this new species found in Turkey is the first record of one on a zodariid. [Paper 🔓️]
- Nine species of predatory phytoseiid mites were found living in walnut orchards in Turkey’s Black Sea region. [Paper 🔓️]
- Eight linyphiid spiders found in Turkey for the first time. [Paper 🔓️]
- A survey of a wildlife sanctuary in northern Rajasthan, India turns up thirteen spider species. [Paper 🔓️]
- A new tarantula species from Kerala, India: Neoheterophrictus chimminiensis, named after the wildlife sanctuary where it was found. [Paper]
- Chrysso angula, a pretty yellow cobweb spider previously reported from the Himalayas, has been found way on the other side of the subcontinent in Kerala. [Paper]
- A new bird-dropping orbweaver, Cyrtarachne biswajiti, found in Bangladesh. [Paper 🔓️]
- Seven new species of jumping spiders (and the previously undiscovered female of another species) found in Yunnan, China. [Paper 🔓️]
- Sea snake ticks (Amblyomma nitidum) were found on a yellow-lipped sea krait in Taiwan for the first time. These snakes hang out on land together, which probably makes it easier for ticks to find them. [Paper] [Sci‑Hub]
- Fourteen new psilodercid spiders described from Indonesia, the Philippines, and Vietnam. [Paper 🔓️]
As always, thank you for reading! Thanks to Leanda Mason and Sebastian Alejandro Echeverri for edits and contributions. Suggestions, corrections, and feedback are very welcome; just drop us a (silk) line at @arachnofiles. 🕷️
Glossary
- acaricide: a pesticide that kills mites and ticks.
- Amblypygi: a group of arachnids known as tailless whipscorpions or whip spiders. Adapted for life in caves and crevices, they are thin and flat, have long, clawlike pedipalps, and have turned their front pair of legs into thin whiplike antennae which they use to feel around in the dark. They don’t make venom or silk and are harmless to humans. You can put them on your face.
- anticoagulant: blood-thinning. This can be good (fewer stray blood clots) or bad (hemorrhage).
- araneomorphs: the group of spider families that includes pretty much any ordinary spider — orbweavers, wolf spiders, jumping spiders, sac spiders, etc. — except tarantulas and other mygalomorphs. You’ll sometimes hear araneomorphs called “true spiders” (though likely not by us). Araneomorphs tend to be smaller and shorter-lived, and their fangs swing in towards each other, like tweezers or scissor blades.
- arboreal: tree-dwelling, as opposed to terrestrial (land-dwelling) and fossorial (burrow-dwelling).
- cribellate: a kind of silk that is tangly rather than sticky. Spiders make tangles in their silk by teasing it out with a comb (called the cribellum) on their back legs. The first araneomorphs made cribellate silk, but many of their descendants switched to sticky silk (ecribelllate; “lacking a cribellum”).
- dermonecrotic: killing skin tissue. I. e., gnarly sores. Google at your peril.
- hemolymph: arthropod “blood”. It uses copper molecules to carry oxygen, unlike our blood, which uses iron.
- mygalomorphs: the group of spider families that includes tarantulas, trapdoor spiders, and other long-lived, chonky spiders. Their fangs move up-and-down, like a snake’s or a vampire’s. Scientists think that the first spiders to evolve were similar to mygalomorphs.
- neurotransmitter: a chemical used to pass signals between nerve cells.
- peptides: the “building blocks” of proteins. A protein is made of a lot of peptides stuck together.
- poisonous: if you eat/bite/lick this thing, you can ingest a toxic substance and get sick. Unlike a venomous animal, if a poisonous animal bites you, it won’t necessarily make you sick.
- spidroin: spider silk protein. The word comes from spider + -in, which is a common protein name ending—think “hemoglobin” or, well, “protein”.
- venomous: if this animal bites you, it can inject a toxic substance and make you get sick. Unlike a poisonous animal, if you eat/bite/lick a venomous animal, it won’t necessarily make you sick.
