Arachnology 2015 – Mitchell, South Dakota

The 2015 meeting of the American Arachnological Society in Newark, Ohio, was hosted by L. Brian Patrick of Dakota Wesleyan University. I live-tweeted this conference for the many who could not attend and to preserve a record of the highlights. This is a read-from-the-bottom document.

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Thursday, June 18

Gosh, it's that time again! Packing to go hear research about #spiders at the #arachnids15 conference in Mitchell SD

Friday, June 19

And ... we're on the road to #arachnids15! Excited to see all my friends & hear about their research

Mitchell SD next two exits!

American Arachnological Society 2015 meeting in Mitchel, South Dakota

The Dakota Discovery Museum, where we gathered on arrival; sadly no photos were allowed in the museum's galleries

Cricket-flour chips at #arachnids15!

Mmm bacon candied jalapeño for the cricket flour chips #arachnids15 yum

Saturday, June 20

About to get started! 39th annual meeting of the American Arachnological Society June 19-23, 2015

Opening remarks by Dakota Wesleyan Dr. Rocky Von Eye #arachnids15 she's a statistician, but not afraid of spiders. Yay!

The campus of Dakota Wesleyan has at least three fountains

The first session will be Systematics & Evolution (Part 1) #arachnids15 moderator Hanna Wood

Dear friends & colleagues, please join in with comments - & questions for the speakers - at #arachnids15

First up: Lauren Esposito on systematics of #scorpions in buthid subfamily Rhopalurusinae

Esposito: New World buthids are monophyletic; also v venomous, 1-k deaths/year

Esposito: the stridulating club-tailed #scorpions Rhopalurus had differences in the stridulatory mechanism; 2 have lost it

Esposito: date of separation of N/S America from Antilles = 35.6my; matches a proposed land bridge GAARlandia

Next: James Starrett, with a revision of the #opilionid genus Cryptomaster

Starrett: Short-range endemism is a major focus of Marshall Hedin's lab

Starrett: Sampling in Oregon. Mitochondrial locus showed a deep genetic break along geographic lines

Starrett: ... within Cryptomaster leviathan, despite v similar male reproductive anatomy

Starrett: male reproductive anatomy may underestimate species divergence in arachnids

Side picked! Spiders are fab! ;-) RT Mike Primavera @primawesome I don't trust you if you aren't scared of spiders. Pick a side.

Next: Sam Evans with a genome-wide phylogeny of the jumping spiders, family Salticidae

Evans: Trying to shore up the backbone of Maddison et al. 2014 phylogenetic tree

Evans: don't need to design primers since probe kit for spiders exists (Hamilton et al.)

Evans: results v close to 2014 tree; a different basal salticid tho; Saltafresia are a clade

Next: Bob Kallal gives a preliminary look at his revision of the Australian leaf-curling orb-weavers Phonognatha & Deliochus

Kallal: Phonognatha mostly found on east coast, possibly an artifact of collection; some spp in New Caledonia, 1 on west coast

Kallal: Prefer leaves but esp in urban environment will use shells, newspapers, cig butts etc. Male lives in retreat w female

Kallal: Originally they were placed with the nephilines, due to leaving the non-sticky web spiral in place

Kallal: his work places them with zigiellines, along with Deliochus, with good support

Next: Marshall Hedin on the many putative cryptic species in a radiation of endemic Californian nemesiid mygalomorphs

Hedin: California nemesiids are not Brachythele & we consider them as belonging to genus Calisoga

Hedin: mtDNA barcoding returned rampant speciation; a pattern of allo/parapatry

Hedin: but there were was v little evidence of speciation morphologically, so looked at nuclear genes...

Hedin: which seemed to confirm multiple species; and in sympatry there was no evidence of gene flow

Last up: Wayne Maddison on the phylogenetic resolution of Habronattus jumping spiders using transcriptomes

Maddison: the 100 or so Habronattus species are notable for their complex & colourful courtship displays

Maddison: the Habronattus genome is about twice the size of the human genome, so used transcriptomes

Maddison: almost the same phylogeny was recovered with various subsets, with good robust support

Maddison: had some evidence of introgression in the clypeatus group, but a weak signal

After the break: Ecology with moderator Pamela Sobel-Thropp


First up in the Ecology session: Michael Draney on the apparent local extinction of a new population of a non-native spider

Draney: Clubiona pallidula is a Eurasian sac spider never before reported in the Great Lakes

Draney: C. pallidula was found in a 2002 survey of arthropods in the invasive common reed Phragmites

Draney: it was the most common spider found in the Phragmites (none found in the cattails sampling)

Draney: sampling Phragmites sites, incl original sites, in 2010. Found 1k spiders, 86 species

Draney: lycosids & tetragnathids were most common; linyphiids most diverse. Had 139 county records & 8 state records

Draney: Clubiona was v abundant, but found zero C. pallidula

Draney: the winter before we found C. pallidula was the warmest in Green Bay history; but it's known from Russian far north...

Draney: local extinctions of non-natives are probably quite common, but I couldn't find any examples in the literature

Next: Sarah Rose on short-term impacts of prescribed burning on the spider community in a small Ohio prairie

Rose: studies of spiders after grassland burns suggest short-term fall in diversity; but they're mostly sweepnet studies

Rose: we re-installed our traps the day after the burn; sampled 4 weeks pre-burn 6 six weeks post-burn

Rose: basically had v little difference in spider abundance & abundance in our pitfall traps pre- & post-burn

Rose: and we saw a variety of anecdotal evidence that some spiders actually survive the burn

Next: Kelton Welch with a presentation entitled The ecology of RNAi: what do spiders have to do with it?

Welch: ecological risk assessment: Hazard x Exposure = Ecologicial Risk; they use a tiered process

Welch: RNA interference "We're not just building a product that kills a bug, but one that messes with the genes of an animal"

Welch: "I coined the term RNA Armageddon, but I don't relly believe RNA is going to destroy the world"

Welch: Monsanto stresses that insects don't have RNA-dependent RNA polymerases, but spiders, ticks & mites DO have RdRp's

Welch: used gut content analysis to see what arachnids had corn products in their guts & looked at their food-chain role

Next: Rick Vetter asks Do spiders transmit bacteria when they bite? The evidence suggests otherwise, he says

Vetter: "Spiders live in dirty icky places, eat dirty icky insects like flies who eat poop, right"

Vetter: some recent studies swabbing spider mouthparts have suggested bacteria transmission

Vetter: so he did some data mining across many studies of many spider bites, looking for any mention of infection

Vetter: presence of pus is actually considered a negative indication for a brown recluse bite

Vetter: in fact, there is research being done suggesting that spider venom KILLS bacteria

Next: Thomas Jones on boom-bust colony dynamics in the socially polymorphic theridiid spider Anelosimus studiosus

Jones: A. studiosus is an arboreal cobweb weaver common along waterways in the southeastern US

Jones: there is an advantage to being social in cooler climates & in smaller colonies; bigger groups compete for resources

Jones: using agent-based modeling to study the sociality threshold

Jones: colonies seem to be very sensitive to winter severity; larger colonies survive winter better

Jones: the populations are dynamic, with unpredictable boom & crash of colonies

And #arachnids15 will be back after lunch, with the first Behavior session

There are only 4 talks in the #arachnids15 afternoon session on Behavior, moderated by Michael Brewer. The next session is tomorrow morning


First up in Behavior: Shawn Wilder on how microcronutrient consumption by female Argiope bruennichi affects offspring survival

Wilder: I'm interested in sexual cannibalism & why do spidrs do it: sexual selection, competition, foraging?

Wilder: some studies have shown that females who cannibalize have more successful hatching & offspring survival

Wilder: some studies have shown that females who cannibalize have more successful hatching & offspring survival

Watching Wilder's stunning video of a female A. bruennichi starting on cannibalistic silk-wrapping even as male is still mating

Wilder: studies have shown that females won't eat the male if not hungry btw, even if he springs into her jaws (as some do)

Wilder: wanted to see if eating the male imparted essential nutrients to the female & her offspring

Wilder: wanted to see if eating the male imparted essential nutrients to the female & her offspring

Wilder: did not see big difference in lab betweem success of cannibals & non among A. bruennichi

Wilder: but micronutrients were important to females, so possibly males in the wild w a varied diet supply those

Next: Drew Hataway on submersion tolerance of the coastal dune-dwelling wolf spider Arctosa sanctaerosae

Hataway: these spiders have their burrows periodically submerged in storm surges during hurricanes

Hataway: they submerged 89 individuals for 4 hours, 94% were unresponsive, but 36% of those returned to activity

Hataway: this is being called "hypoxic coma"

Hataway: we've tried w forest lycosids like Pardosa etc & none of those survive drowning like shore-dwelling Arctosa

Next: Paula Cushing with a new species of myrmecophilic spiders from Big Bend, Texas

Cushing: this spider was collected near & inside nests of the seed harvesting ant Pogonomyrmex rugosus

Cushing: they mature in late summer; we don't know what family they belong in

Next, last talk of the day: Kerri Wrinn on the effects of autotomy on male-female interactions in Pholcus phalangioides

PS from Cushing: also found staphylinids & silverfish, both common myrmecophiles, in the ant nests

Back to Wrinn: cellar spiders are often nliving in close proximity to one another, often as male-female pairs

Wrinn: 47% of the spiders collected in cellars were in pairs; 18% were missing a leg; only 4.5% were in a pair & missing a leg

Watching Wrinn's video of P. phalangioides leg-tapping courtship, w successful mating & not so much (leg loss)

Wrinn: females missing a leg were more aggressive

Wrinn: but overall there were more positive interactions than negative in all pairings

Tomorrow at 9: 2nd Systematics & Evolution session ... followed by Taxonomy & Diversity, including {{quick horn toot}} my talk on LinEpig

Meanwhile, Mitchell's claim to fame - the Corn Palace. It has big outdoor murals made out of ears of corn, and has been a thing for many decades

Mitchell is also home to the museum and library of George McGovern, the Democractic candidate who lost resoundingly to Richard Nixon in the 1972 presidential election. Here is a photo of the senator with someone who did end up serving as president

Sunday, June 21

Good morning, #arachnids15 is back in session, with part 2 of Systenatics & Evolution, moderated by Michael Draney

First up: Hannah Wood with Need for speed: extremely rapid predatory strikes evolved repeatedly in trap-jaw spiders

Wood: spiders in Mecysmaucheniidae have domed heads & greatly modified long chelicerae, which snap together at great speeds

Wood: it's hard for small organisms to make fast movements; a compensating mechanism is "power amplification"

Wood: photographed the jaw motion at speeds of 30,000 frames/second. We saw this video!

Wood: the fastest species attained peak speeds of 26.5 m/s in less than 0.18 milliseconds

Wood: the phylogeny showed the power morphology to do this evolved 4 separate times

Wood: this is the 1st discovery in arachnids of power amplification mechanisms

Next up: Paul Selden on ancient spiders in salt lakes

Selden: the Green River formation is the largest great lake formation in the fossil record; the biota is v diverse

Selden: until recently, only a single specimen (Linyphia byrami Cockerell, 1925) had been described

Selden: now spiders from the families Uloboridae, Hersiliidae, Selenopidae & Thomisidae described

Selden: also seeing some spider fossils from the Florissant formation & Crato in Brazil

Selden: in Crato spider fossils have legs curled up, like "dead on the carpet"

Selden: spider fossils from the other 2 places have legs stretched out like they died on the water

Selden: conjectured this reflected the level of salinity in the water; Crato also had fish mass die-offs

Selden: this was supported w some spider-drowning experiments in different salinity levels

Selden: thus fossil spider leg flexure can serve as a proxy for the paleosalinity of ancient lakes

Next: Michael Brewer on the potential dual roles of venom evolution in the genus Tetragnatha

Brewer: spider genomics is burgeoning. They have large genomes for arthropods, but they are hard to assemble

Brewer: so for looking at diversification in species radiation in Hawaii decided to use venom

Brewer: of 114 down-regulated genes, only 3 were homologous to known spider toxins (& they are known to be antimicrobial!)

Brewer: matched up transcriptomes w proteomes looking for venom dimorphisms... & mate recognition

Brewer: ... given the unusual mating behavior (cheliceral locking) in many tetragnathids

Next up: Ingi Agnarsson on CarBio, whichs aims to do comparative biogeography of two 'widespread species' in the Caribbean

Agnarsson: interested in developing & testing an index of dispersal ability over geo time among different taxa

Agnarsson: comparing dispersal events of Argiope argentata & Spintharus flavidus, & GAARlandia vs overwater hypothesis

Agnarsson: Argiope is widespread; Spintharus, the poorer disperser, represents an ancient & previously undocumented radiation

Next: Greta Binford on ancient colonization of N America via the Caribbean by recluse spiders & evidence for cryptic radiation

Binford: this is another Team CarBio project... There are 6 described Caribbean Loxosceles & 43 in N & Central America

Binford: Loxosceles is a mid-level disperser; oldest common ancestor lived in western Gondwana

Binford: Does monophyly of N Am + Caribbean hold up? Yes. Does radiation reflect geographic history?...

And that's it for Systematics & Evolution talks at #arachnids15 ... after the break, Taxonomy & Diversity. Stay tuned!


This is the #arachnids15 Taxonomy & Diversity session, moderated by Shawn Wilder

First up, Sandra Brantley on 4 families of spiders in adjacent conifer forest sites in northern New Mexico

Brantley: ... or how to get around frustrations in spider ecology

Brantley: worked at Valles Caldera National Preserve since 2011 & adjacent Bandelier National Monument for almost 20 years

Brantley: many species from Caldera I'd never collected from Bandelier, altho habitats are similar: mostly conifer 2500-2700m

Brantley: habitat specificity ranged from the greatest in Linyphiidae & Thomisidae, followed by Gnaphosidae

Brantley: longitudinally a lot of variation in abundance year to year in Bandolier, with rel low counts being common

Brantley: discussion of the value of databases in such work; they use SCAN, which has useful mapping functions

Brantley: can use the data for niche modeling together with climate data & identify what will be suitable-habitat predictions

Brantley: so get your specimens databased "Let us work to overcome the phrase 'Known only from the type locality'!"

Binford: & we see different genetic structure across short geo distances among cave populations

Binford: taxa within Caribbean islands are not monophyletic... but 28 mya Cuba was a series of different islands

Next: Mia Spaid on spiders of the Everglades National Park: changes in species composition

Spaid: the Everglades is right on the border of biogeographic areas; they looked at 4 habitats

Spaid: the Everglades are much reduced from their original extent, & w v different water flow due to diverting by man

Spaid: was able to use the Jim Berry collection from the late 1960s, & compare to recently collected material

Spaid: hardwood hammock habitat was the most diverse, followed by pinelands, then sawgrass, & willowhead last

Spaid: the greater diversity in 2000 vs 1960s may be largely accounted for by collection differences

Spaid: faunal-community structure was v different between the 2 collection periods & among the 4 habitats

Next: Marc Milne with a new species of Liocranoides (Tengellidae) from Alabama

Milne: this study began, like so many do, with rumors of rare spiders, in some cave

Milne: Anvil Cave is a "maze cave" w almost 13 miles of passageways; entrance reached via canoe trip

Milne: Ingram Cave is just a hole in the ground, which opens up into a big room

Milne: saw some troglobitic fauna, altho did not find the rumored rare spiders, but ...

Milne: discovered a cohabiting male & female Liocranoides in Ingram Cave

Milne: Liocranoides Keyserling 1881, btw, contains 5 species of mostly cave-dwelling, medium-sized spiders

The last presentation of this session will be my talk on LinEpig & online taxonomic reference resources...

Nina Sandlin I did not get a chance to tweet it, but my talk is here and the demo is here.


We're about to start the 2nd Behavior session at #arachnids15, moderated by Kelton Welch

First up, Jonathan Coddington, a last-minute addition to the lineup because the planned talk by George Uetz fell through

Jon Coddington is talking about the biodiversity of life on Earth. He leads the Global Genome Initiative #arachnic

Coddington: Remember there is really only one genome

Coddington: "For protein-coded genes, we are only about 50% different from a banana"

Coddington: There are about 10,000 total families of life on earth

Coddington: the best-known families of life on earth, based on online data, are plants & a minnow family

Coddington: ... and just lots of interesting info from the Global Genome Biodiverstiy Network

Next: Rachael Mallis on the courtship in Tengella perfuga, w all that strumming, stroking & stilting

Mallis: male courtship - preening & grooming, abdomen shaking, stroking, & "stilting" up on his long legs & silking over her

Mallis: the deed itself is v quick - and then you get a big egg sac w "a thousand babies"

Btw, in Mallis' video, the male's stroking was v focused, & the female proved quite eager

Next: Colton Watts on diel patterns of courtship in the subsocial spider Anelosimus studiosus...

Watts: ...& how they may not be driven by female aggression

Watts: A. studiosus males prefer to court docile females; & females have diel patterns of aggression

Watts: used half-light to mimic dawn & dusk; looked at females from single-female & multi-female webs separately

Watts: male courtship did vary w time of day, but only w females from multi-female webs

Watts: clock shifted females from multi-female webs were less aggressive toward prey at dusk

Watts: but males treated clock-shifted females differently than clock-normal females

Watts: those females were more aggressive; clock-shifting can have a wholesale effect on behavior

Watts: clock-shifting probably really stresses them out, so what we had was jet-lagged spiders

Next: Anne Danielson-Francois with evidence for sexual selection on spider fangs and behavioral cost

Danielson-Francois: males of the long-jawed orb-weaver Tetragnatha elongata live about as long as females do & eat

Danielson-Francois: but the male's chelicerae & fangs are subtly but definitely different from female's

Danielson-Francois: is natural or sexual selection fashioning the more delicate but longer fangs of the males?

Danielson-Francois: 24-hr fly-catching efficiency is lower for adult T. elongatga males than for females

Danielson-Francois: after mating, males like to steal the female's food item

That was the last talk #arachnids15 of the day. After thebreak, we will go to the poster session

Monday, June 22

Good morning from #arachnids15. Getting a late start, as a storm knocked out Internet here...

This session is Webs & Silk, moderated by Sandra Brantley

1st: Brent Opell on evolutionary & environmental plasticity in the material properties of orb-weaving spider glue droplets

Opell: Glue droplets in web viscous capture thread differ in hygroscopicity, adapting to habitat humidity

Opell: glycoprotein material properties can vary 630-fold in toughness across the 3 species studied

Opell: and can vary 2- or 3-fold within a species depending on the ambient humidity

Next: Sean Blamires on property variation in spider silks: ecology, evolution & biomimic implications

Blamires: major ampullate silk aka dragline silk is the spider silk studied for its high strength properties

Blamires: silk production sequence step 1 protein secrection; protein mix determines strenght vs extensibility

Blamires: post-secretion step 2 = crystalline structure

Blamires: step 3 involves effect of exposure to water (humidity) & wind

Blamires: amorphous alignment had the greatest influence on material properties of the silk

Next up: Sarah Stellwagen on intra-orb-web capture spiral adhesive droplet distributions

Stellwagen: a triad of spigots on the posterior lateral spinneret make the sticky threads in an orb web

Stellwagen: Brent Opell had noticed a difference in stickiness between top & bottom as well as outside vs. inside of webs

Stellwagen: collected fresh webs in the morning to measure properties of droplets from different parts of the web

Stellwagen: as in Brent's work, I use angle formed when pulling on droplet to calculate Young's Modulus (measure of toughness)

Stellwagen: spiders run down in the web more easily than up, & they fill in the bottom first

Stellwagen: droplets at the bottom of the web are larger & extend for twice the length of time in the lab

Stellwagen: there is a 44% difference in toughness of the droplets between v top & v bottom of the same web

Next: Milan Rezá c asks, Do the proportions of the spinning duct influence the material properties of major ampullate fibers?

Rezá c: the toughest dragline silk known is produced by the orb weaver Caeostris darwini from Madagscar

Rezá c: the spinning duct has an S-shaped curve; silk passing thru it is elongated by shear forces

Rezá c: comparing stress-strain curves & length/width measures of each leg of the duct in several species...

Rezá c: we found counsiderable variation between species in the length of the loop or curve of the duct

Rezá c: toughness significantly correlated w duct width

Rezá c: duct length increase out of proportion to spider body size across species

Rezá c: larger spiders produce stronger & tougher fibers, likely due to the elongation of spinning ducts

That was it for this year's scientific talks

Now Paula Cushing talks about the 2016 ISA/AAS joint meeting in Golden, Colorado

Cushing: Golden is a cute little town about 40 min from Denver Intl Airport

Cushing: Ingi Arnarsson & Linda Rayor are organizing the program; they're organizing symposia

Cushing: the meeting will be at the School of Mines (NOT "mimes")

Cushing: expecting ~350 attendees, & planning 2 concurrent tracks

Cushing: meeting will be July 2nd to the 9th, w BBQ & fireworks for the Fourth

Cushing: planning lots of fun & beautiful excursions & things to do...

Cushing: (btw, the International Society of Arachnology - has its congress every 3rd year)

Cushing: registration will be $300-$350 per member (a bit more than usual bec it's the Intl); but dorms will be v cheap)

After the #arachnids15 banquet, we had the annual & auction raised $1,103 for arachnology student research

This cute but baffling alleged spider, for example, went for $7 to Laurén Fogg at the #arachnids15 auction

@sc_evans: Last item: shirt stolen off Marshal Hedin's back just last night. Sold for $57. #arachnids15 #thatMarshalScent

@sc_evans: The famed shirt, now proudly owned by Greta Binford. (right, w/ @nsandlin)

In the #arachnids15 student competition, Robert Kallal won 2nd place for his talk on systematics of the Australian leaf- curling spider

Sarah Stellwagen was the #arachnids15 student competition winner w her talk on top-vs-bottem differences in web silk adhesion

High schooler Jihoo Kim beat out college students with his winning #arachnids15 poster on Dysdera crocata not limiting its diet to pill bugs

Congratulations #arachnids15 student competition winners!

#arachnids15 poster competition winner Jihoo Kim is working on the arthropod collection at the @fieldmuseum this summer

Tuesday, June 23 and beyond

Ready for the field trip. On the way, we had to wait for a passing house. In South Dakota, you see whole lots full of houses ready to take to the road

The field trip was at the Madison Waterfowl Production area. Here are some fauna and other things to be aware of out there

It was a lovely spot w a native prairie

One thing we saw in the prairie was some thriving ant nests. Here is how to spot them

@sc_evans: Rounding up tidbits from #arachnids15. Cool clouds on the drive in from Sioux Falls:

@sc_evans: Mitchell is a classic hokey American town. World's only corn palace (read: corn gymnasium)

RT Sam Evans @sc_evans My collab @8legs2fangs saw @nsandlin's LT of my talk, emailed me in SAME SESSION w/ new insights. #arachnids15 + Twitter = progress!

And finally, a lot more meeting pictures from Jack Owicki.

About this document

By giving multiple highlights from almost all speakers, I have exceeded the size that can readily be handled by the Storify platform, which I had used in earlier years. This is thus a custom-gathered collection of tweets; those not identified are by me. I have taken the liberty of tidying the content by correcting misspellings and filling in some missing information. If any errors or ommissions remain, please let me know and I will set them right. My contact info is here. I also added a few images that never got tweeted, as well as linking to the pictures Jack Owicki from Stanford took throughout the meeting.