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Arachnews: July 8, 2020

Your regular roundup of arachnid art, news, and science.

In this edition: looking back at the American Arachnological Society’s first online meeting; a shakeup in the taxonomy world; research on venom, orbweaver hunting, and things that hunt spiders; new species; and more.

Terms in bold are defined in the Glossary at the end of the post.

Art & Social Media

A harvestman with a snail stuck on him… • Erin Powell
…and a crab spider sheltering in a snail shell • Tylan Berry
An impala with a spiderweb stuck to its horns. Note: while there is an older similar image, this one seems to be new. • Jackie Du Toit Liebenberg
This Nick Porch photo of a harvester with massive eyes from several years ago went viral when Twitter user @Mycterops reposted it.
A jumping spider still bearing its old carapace on its head • Trần Thế Ngọc
  • Thomas Shahan encounters a dimorphic jumping spider (Maevia inclemens) who takes care of a pesky mosquito for him. [YouTube]
  • Peacock spiders as art: a thread. [Twitter]

Events & News

Zoom group photo via LABRE
  • The American Arachnological Society’s online meeting took place last week! There was a keynote by Martín Ramírez; workshops on iNaturalist and supporting BIPOC scientists; a late-night jam session; a poster session; and a series of talks. Relive the magic with the #Arachnids20 hashtag.


Every year, a company called Clarivate publishes Journal Citation Reports, which lists scientific journals’ impact factor—how often articles that appear in a publication are cited by others. Impact factor is often used as a rough proxy for how influential and important a journal is, and early career researchers are often judged by the impact factor of the journals they publish in.

This year, Clarivate essentially blacklisted the animal taxonomy journal Zootaxa for too many self-citations. In some cases, papers citing lots of papers from the same journal can indicate that the journal is trying to artificially inflate its ranking. In Zootaxa’s case, it is one of the very few journals that is just for papers about new or reclassified animal species. There are also very few scientists who specialize in taxonomy: for every family of animals, there may be one or two experts in the entire world—if you’re lucky. So there are only a few people to cite, and only a few places to publish in. As a result, over 25% of all new animal species are published in Zootaxa.

As frequent readers of these pages will know, no one gets salty like taxonomists. And the taxonomists are mad.

  • “While the other members of the Council [of the International Society of Arachnology] approve of the message of this letter, its intemperate style is entirely my own,” begins Wayne Maddison’s letter on behalf of the ISA. [Twitter]
  • Maddison also explains the situation in a thread on his personal account. [Twitter]
  • Ivan Magalhaes estimates that 40% of all new spider species in the last five years were described in Zootaxa. [Twitter]
  • Token vertebrate take: Yi-Kai Tea, a. k. a. Kai the Fish Guy, also has an informative rant. [Twitter]
  • Retraction Watch reports that Zootaxa is in touch with Clarivate on resolving the issue. [Retraction Watch]


A female Argiope radon Wikimedia user Summerdrought
  • Orbweavers, which are sit-and-wait predators that may have to go a long time between meals, have a pretty slow metabolism. A study on Australia’s northern St. Andrew’s cross spider (Argiope radon) found that female spiders had a wide range of resting metabolic rates. After mating, however, their resting metabolic rates dropped dramatically — about a third of what they were before. This probably means they’re redirecting their energy into growing their eggs and making egg sacs. [Paper] [Sci‑Hub]
  • The orbweaver Micrathena gracilis is a strictly daytime forager, taking down its web at the end of the day—even though there’s a surge of flying insects at dusk. What’s up with that? This is a question for the nascent field of chronoecology, which, to my disappointment, is not about when an organism goes back in time and becomes its own predator and also its own prey. I saw this as a talk at the AAS meeting! [Presentation]
  • A typical Slovakian vegetable garden hosts a surprising diversity of oribatid mites — some cosmopolitan, others plant-specific. Beans had the highest abundance, with an average of 563 mites per square metre; however, that’s nothing compared to forests, which can have hundreds of thousands of mites per square metre (and those are just the oribatids). [Paper 🔓️]
  • Mud dauber wasps are devoted parents! They hunt down spiders and sting them with venom that keeps them alive but paralyzed. Then they drag the spiders back, cram them into a mud nest cell, lay an egg in there, and seal it up. The wasp larva hatches to a fresh supply of food. In southern Nebraska, mud dauber nests in agricultural areas had more spiders (and wasps) than ones in forests. [Poster 🔓️]
  • Oh boy, one of my favourite things: an exciting Wolbachia preprint. Wolbachia are widespread endosymbiotic bacteria that live inside arthropod cells, particularly eggs. They are infamous for manipulating their hosts’ fertility, reproduction, and sexes to their own advantage. So far, scientists have discovered 16 separate Wolbachia strains, called “supergroups”. According to a not-yet-published paper, a new supergroup has been found in pseudoscorpions from France. [Preprint 🔓️]
  • Another cool preprint: a group of researchers, mostly from Germany, have sequenced the genome of the European wasp spider (Argiope bruennichi). There are very few spider genomes sequenced—less than a dozen species out of some 50,000. This one is also sorted into chromosomes for convenience. [Preprint 🔓️]


  • When plants are exposed to more intense light, they grow thicker leaves that can photosynthesize more. In turn, this affects two-spotted spider mites (Tetranychus urticae) that feed on them. The mites have more offspring, but cause less leaf damage — juicier leaves mean they can get more food out of a given spot, so they don’t forage as much. [Paper] [Sci‑Hub]
  • “The enemy of my enemy is my friend” holds true for the predatory mite Neoseiulus barkeri and the thrips Scolothrips takahashii. Both engage in cannibalism and prey on each others’ immature stages, but these behaviours were much reduced when researchers introduced a third species they both prey on, the citrus red mite (Panonychus citri). [Paper] [Sci‑Hub]
  • The usual predatory phytoseiid mites aren’t useful for controlling the tomato russet mite (Aculops lycopersici), because they’re too big to maneuver around the hairs on the surface of tomato leaves. However, mites from the family Tydeidae are small enough to fit underneath the hairs. They don’t wipe out the tomato russet mites, but they can limit the extent of the damage. [Conference paper 🔓️]


  • Congenital insensitivity to pain is a rare and dangerous condition where, well, you’re born unable to feel pain. A peptide derived from the venom of the tropical huntsman (Heteropoda venatoria) was able to restore pain responses…IN MICE. [Paper 🔓️]
  • Researchers in Assiut Governorate, Egypt have designed a training course and educational materials to teach nurses how to treat scorpion stings. Nurses learned how to tell different types of scorpions apart, how to recognize sting symptoms, and how to care for patients in an emergency room setting. [Paper 🔓️]
  • Here’s a review of the pros and cons of scorpion venom. Cons: it can kill you. Pros: there’s a surprising variety of medical applications. While in these pages we mostly see venom being researched to treat pain, different compounds in venom may be effective against bacteria, fungi, and viruses. [Paper 🔓️]


Several new species of Heterophyrnus amblypygids. C and D show H. javieri. • Seiter & Gredler (2020)
  • A new species of amblypygid from Colombia, Heterophrynus javieri, named after Javier Maldonaldo-Ocampo, an icthyologist who died in a boating accident during the expedition. [Paper] [Sci‑Hub]
  • Two new species of Gaeolaelaps mites, free-living predators of smaller bugs, found in sugarcane fields and pasture in Brazil. Until now only one Gaeolaelaps species had been reported in the country. [Paper] [Sci‑Hub]
  • A new liocranid spider, Agraecina salsicola, found in a salt marsh in northern Tunisia. [Paper] [Sci‑Hub]
  • A survey of phytoseiid mites on the Mauritian island of Rodrigues turns up 18 species. Phytoseiids are predatory mites that eat mites and other plant pests, and seven of the species found are widely used for that purpose. [Paper 🔓️]
  • A new leptonetid spider, Cataleptoneta aydintopcui, found in a cave in southern Turkey. It’s named after the Turkish arachnologist Aydın Topçu. [Paper 🔓️]
  • A review of pachylaelapid mites from Iran, including a new species, Onchodellus masani. The authors helpfully explain that pachylaelapids are “coprophilous, saprophilous and euryhygrophilous detriticoles, psychrophilous and insecticolous species”, which means they live on or among excrement, dead or rotting things, insects (e. g. in ant nests or riding on beetles), and in generally cold, wet conditions. [Paper] [Sci‑Hub]
  • Two new Protoribates oribatid mites, P. sichuanensis from Sichuan, China and P. tibetensis from Tibet. The paper also has a guide to identifying Protoribates in China. [Paper] [Sci‑Hub]
Sadly, Whakomoke guacamole is not pictured here. • Hormiga & Scharff 2020
  • Two new genera of small, sneaky, spiky-legged malkarid spiders from New Zealand, Tingotingo and Whakamoke, comprising 11 species between them. The new species names come from Māori words for various characteristics (e. g. “forked”, “bristle”, etc.) or where they were found—except for Whakamoke guacamole, “an arbitrary combination of letters”, which is taxonomist for “this is an inside joke”. Say it out loud. It’s fun. [Paper] [WSC]


  • chronoecology: the study of organisms’ circadian rhythms in the context of their environment.
  • early career researchers (ECRs): scientists who are just starting out in their careers; typically anywhere up to 5–10 years after finishing their PhD. ECRs are generally broke, precariously employed, and particularly vulnerable to workplace exploitation and bullshit standards.
  • endosymbiont: A symbiotic organism (-symbiont) that lives inside (endo-) another species. Typically these are bacteria living inside the cells of plants or animals. We covered a lot of arachnid endosymbionts in the March 9th issue of Arachnews.
  • impact factor: how often a publication’s papers are cited in other papers. Originally meant to help librarians select in-demand journals to subscribe to, impact factor has come to be used as an indicator of a journal’s influence and importance.
  • preprint: a draft research paper made publicly available before it has undergone peer review. Preprints allow scientists to share vital data and get early feedback on their ideas, but should not be viewed with the same confidence as a published paper.
  • taxonomy: the science of naming and classifying organisms. When species, genera, families, etc., are described or reorganized, that’s taxonomy.



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