neville park
Jul 17 · 10 min read
A wolf spider stands on a snake’s head. Source: Asia Murphy.

Art & Media

i was walking around in the meadows looking for snakes
i looked at the log
i saw a snake face
and then a spider face

says Asia Murphy about this odd couple spotted in Lassen County, California. The snake was collected for research; the spider’s whereabouts are unknown.

Male and female Nephila
  • Check out this spectacularly pedipalped (is that a word?) Forsteropsalis bona harvestman from New Zealand cleaning his legs! Photo by Erin Powell.

Dispatches & Social Media

Source

  • Gail, a Cuban scorpion (Heteroctenus garridoi) who was inadvertently brought back to Canada in luggage, has given birth to an adorable brood of scorplings at the Victoria Bug Zoo. “When the offspring get a little bigger, zoo officials say they will be removed from Gail’s cage in case she mistakes them for prey and devours them.”
  • After four years of trying, Victoria Butterfly Gardens’ Justin Dunning finally got a time-lapse video of his nine-year-old Theraphosa stirmi molting.
A huntsman preying on a possum. Source: Justine Latton.
In BioWare’s Dragon Age: Inquisition (2014) the player defeats spiders representing their fears, including “ironically, spiders”.
  • “Entomoludology: Arthropods in Video Games” is a comprehensive tour through arthropods in video games, with an eye on how these animals are presented. Truly some amazing stories in here. Curious about a Japanese card and arcade game called “Mushiking” (literally ‘Bug King’) that holds the Guinness world record for the most game official tournaments? (You’ll never guess how many. It’s a lot.) Want to know what real-world animals are named after Pokémon? Trust me, give this a read. (BONUS: The author of the paper is running a crowdfunding campaign to get a “‘study” about Pokemon biology published in a “real” (read: will publish anything for a price) scientific journal.)
A toy Pokéball bug cage.
  • Related: The Japanese culture of kids collecting arthropods inspired the creators of Pokemon, which in turn inspired kids around the world to become entomologists and arachnologists. And now there is Pokémon-inspired bug catching gear! Retails for 1300y, or about $13.

Education & Outreach

  • Fiona Cross appears on New Zealand kids’ show Fanimals, talking about why she loves spiders. She introduces some common NZ jumping spiders like Trite planiceps and Hypoblemum albovittata, as well as the Kenyan spiders she works with, like Evarcha culicivora and Portia.
  • Caitlin Henderson of Minibeast Wildlife has an explanation of how people came to believe Australia’s white-tail spider (Lampona) had dangerously necrotic venom, and how we now know it doesn’t. Includes high-quality photos.
  • University of Minnesota Morris prof PZ Myers and students are looking for spiders in local sheds and garages to track their populations from year to year. Myers is also blogging about how it’s going so far.
  • For How Stuff Works, Jesslyn Shields has an informational article debunking the many myths about the brown recluse and its bite, featuring quotes from Rick Vetter, of course.
  • Gil Wizen introduces one of the lesser-known arachnid orders, Schizomida or short-tailed whip scorpions, including great macro photos and details about their life cycle and behaviour.
  • The Curious Kids series at The Conversation answers children’s science questions. In a recent column, Samantha Nixon and Andrew Walker give a simple explanation of what a spider’s eyes (or absence thereof) can tell us about their lifestyle and hunting strategy.

Research & Observations

Sexes and Mating

The two morphs of male Maevia inclemens. Source: Lietzenmayer, Clark & Taylor, 2019.
  • The jumping spider Maevia inclemens is called the “dimorphic jumper” because its males come in two forms: one with head tufts and one with stripes. We still aren’t sure why. One new hypothesis: the stripes might resemble possibly dangerous insects’, to get females’ attention without making them think about food.
  • Many spiders are sexually dimorphic in their morphology and behavior, but what about how and when they are active? In a species of jumping spider, activity peaks in the morning for both sexes. But for a species of running crab spider, females were most active at night, and males were most active early in the morning.
  • Quindina opilionids are unique in that males build nests and guard the eggs. A nest must pass inspection by a female in order for her to lay eggs there. But in the rainforest of Costa Rica, rain frequently washes away the nests, and that affects males’ reproductive success.
  • A bilateral gynandromorph ant-mimic jumping spider was found in Japan! That is, it appeared half male and half female, divided right down the middle. This spider acted like a male, confronting male spiders and trying to court female ones. This seems to be consistent with the (few) other observations of gynandromorph arthropods.
  • Did you know that some wolf spiders actually make funnel webs like grass spiders? One such species is the South American Aglaoctenus lagotis…but the differences in mating behaviour, among other things, suggest that perhaps we’re dealing with two species mistakenly lumped together.
  • Trechaleids are Central and South American spiders very similar to pisaurids, in behaviour as well as form; the females carry their egg sacs around with them, which limits their ability to find food. But pregnant females also take a hit even before they’ve made an egg sac.

Sensoria

A jumping spider being held by a bit of wax on a stick, as part of an experiment to test its vision. Source.
  • Opilionids (harvestmen) of the sub-order Eupnoi, which includes common temperate-region denizens like Phalangium opilio and Dicranopalpus ramosus, have a special gland called an ozopore that they use to release chemicals. We’re not sure what for, yet, but this review summarizes some possibilities and research directions.
  • Comparing the visual system of vinegaroons to other arachnids’ can help us figure out the evolutionary relationships between them. Yes, this is secretly another “horseshoe crabs are arachnids” paper.
  • They could have called this paper “Good vibrations” but they didn’t: “The effects of microhabitat specialization on mating communication in a wolf spider”. A wolf spider in the woods of central Florida, Schizocosa floridana, does all its courting and mating on oak and pine leaf (needle?) litter, and it turns out those are better than sand for tramsmitting its vibratory songs.
  • Here’s a preliminary framework for investigating how noise pollution impacts invertebrates. While most research into noise pollution is about long-range air- or water-borne sound, the kinds of noise that affect bugs most are nearby airborne noise and noise transmitted through the ground.
  • Scientists have only recently discovered that jumping spiders, in addition to having excellent vision, can hear sounds. In his Master’s thesis, Philip Denbaum tests whether jumping spiders use sound cues to know where to look [PDF].
  • Two species of jumping spider, Portia fimbriata and Trite planiceps, go head-to-head in an obstacle course designed to test their navigational ability. The differences between their performances might be due to how complex their home environments are.

Biodiversity

Silk

Interspecies Relations

An amblypygid coated in fungus. Source: Jonas O. Wolff.

Miscellaneous

A fiery-haired paradise jumper, Habronattus pyrrithrix, with US penny for scale. Source: Ihle & Taylor, 2019

Taxonomy

New records

Our knowledge of which spiders live where is constantly being updated, thanks to finds like these.

Checklists

New species

Introducing an entirely new family of spiders that hang out with ants! Source: Ramirez et al. 2019

Over fifty newly discovered arachnid species were described in June. Some of the highlights are presented below.

A new species of schizomid. Source: Abrams et al. 2019

Many thanks to Sebastian Alejandro Echeverri and Ivan Magalhaes, whose contributions were essential to this month’s edition. Corrections, ideas, and items for next month are welcome! Leave a comment or drop us a (silk) line on Twitter at @arachnofiles.

Arachnofiles

Arachnids are fascinating. We write stores about these amazing animals, and the scientists that study them.

neville park

Written by

Jane Jacobs in the streets, Robert Moses in the sheets. http://pronoun.is/ze

Arachnofiles

Arachnids are fascinating. We write stores about these amazing animals, and the scientists that study them.

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