Studying Arachnids All Over the World

aula Cushing is senior curator of invertebrate zoology on the Denver Museum of Nature and Science. Over the course of her profession, she has studied a wide range of arachnids—not solely spiders, but in addition a number of the stranger lineages reminiscent of solifugids, extra generally often called camel spiders (though Cushing notes that the identify spider is a deceptive misnomer on this case). Cushing started her profession learning the antipredator behaviors of spiders. As a grasp’s pupil, she obtained two Sigma Xi Grants in Support of Analysis to finish this analysis. Cushing spoke with American Scientist editor-in-chief Fenella Saunders earlier this 12 months. This interview has been edited for size and readability.

How do you describe how you slot in your subject of examine?

I’m a generalist arachnologist. I’ve printed on spiders, scorpions, and a number of other teams of arachnids. I’ve printed a variety of taxonomic work, some biogenetic analysis, some conduct analysis, in addition to morphological work. I’m a generalist in that sense. Since my grasp’s work, I’ve branched out to a bunch of various subdisciplines past the behavioral points that I researched again then.

What acquired you interested by biology?

I keep in mind distinctly as a bit of lady pondering how bizarre it was that we dwell on this planet that has all this life on it, and but so far as we all know it’s the one planet in our Photo voltaic System, possibly the universe, with life. I began pondering, How did that come to be? In my very logical little lady mind, I assumed, ‘Effectively, if I need to perceive why life exists on this planet, then possibly I’ll examine nature.’ I went to certainly one of my older siblings and requested if there was a phrase for an individual who wished to review nature. My smart older sibling stated, ‘Why sure, a naturalist.’ They pulled out a dictionary, as a result of again within the day you had dictionaries, and opened it to naturalist. I used to be amazed that someone else had considered that earlier than me. And I assumed, okay, that’s what I need to do.

How did you begin learning spiders, particularly?

I grew up within the Washington, DC, space. In highschool I grew to become a volunteer naturalist at a park. After which I interned on the Smithsonian Nationwide Museum of Pure Historical past. I spotted that I used to be extra taken with animals than crops. And by way of animals, one way or the other I knew that there have been much more fascinating inquiries to ask about arthropods than there have been about vertebrates: There’s much more species variety. And so I utilized and acquired to be an intern on the Smithsonian’s insect zoo. I gave my first spider program at a park as a highschool pupil.

I went to varsity at Virginia Tech, and I came upon from a good friend that as a school pupil, you might volunteer to do analysis in a professor’s lab. I assumed that will be a good way to see if I favored it and if I had the talent set to be a researcher and a biologist. There have been two professors within the biology division who did analysis on arthropods. One was a butterfly individual, and I spotted that butterflies are just like the birds of the arthropod universe, in that they’re highly regarded. So plenty of individuals wished to review butterflies. I wished to steer clear of that. The opposite professor was Brent Opell, who studied spiders. I made an appointment and met with Brent. He was very open to having this nice dialogue with me and welcomed me into his lab. He grew to become my grasp’s diploma mentor. He was an excellent mentor, mild and supportive. That’s how I acquired began within the subject of arachnology. He took me to my first assembly as a freshman the place I gave my first presentation.

What drew you to the sphere of arachnology?

The sphere of arachnology is a really small, intimate subject. The sphere may be very supportive of amateurs, or what we’d name non-PhD researchers. They’re very supportive of scholars and anybody who’s within the subject. I actually favored that setting. I’ve at all times felt like science strikes ahead sooner in that form of a supportive setting than it does when everyone seems to be competing towards each other. Being at that assembly made me blissful about my selection of subject.

So it was each a fascination with the animals, but in addition simply feeling welcomed into this subdiscipline of biology [that drew me to this field of study]. I believe that’s an excellent necessary message to get throughout. Science nonetheless suffers from a scarcity of variety. We discuss loads about DEAI [diversity, equity, access, and inclusion], however generally enhancing and growing variety is so simple as making individuals really feel welcome, making them really feel like their concepts are being listened to.

It is fascinating that your GIAR grant was associated particularly to predator response conduct in spiders, as a result of individuals often consider spiders as predators, not as needing defensive mechanisms.

Plenty of birds that eat arthropods, even hummingbirds, will eat spiders readily, as will plenty of mammals and reptiles. It was intriguing to me to flip the query. As an alternative of specializing in how spiders hunt their prey, I thought of how they escape predation.

On this case, once I was a grasp’s pupil, I observed that whenever you would brush previous the webs of sure spiders, they might bounce out of the webs. That appeared like an odd response. It was in all probability an antipredator response, however nobody had examined that apparent speculation. It was intriguing to me to attempt to determine methods to check it. I did check it, and for me, that was actually satisfying, from the very starting of deriving the query to the top product.

The Grant in Support of Analysis typically is what offers you the self-confidence to know that your concepts are legitimate. I believe that alone is such a treasure and such a strong message.

What’s your pet peeve, the factor that folks consider about spiders that you just want they might cease believing?

As a museum curator I reply just about a query a day, and nearly all of them are, ‘I discovered a spider in my home. Is it toxic? Is it going to kill me? I’ve a baby! Is my baby going to die?’ So my pet peeve is that folks have this irrational worry. We’re giants in comparison with these tiny little organisms.

I’ve this speculation that you just see this irrational worry of spiders largely in well-developed nations like the USA and western Europe, the place nature is separated from our lives by concrete and asphalt. Due to that disconnect between our lives and nature, people in these nations develop this irrational worry of organisms, 99 p.c of which can’t harm us. Once I journey to tropical nations you don’t see that form of overwhelming, irrational worry of arthropods, spiders, and different organisms, as a result of nature is way more part of day-to-day life in these tropical nations. Usually properties don’t even have screens on their home windows. Nature actually does come inside. I could possibly be completely fallacious, however that’s only a sample that I’ve observed by touring world wide.

Spiders are themselves prime predators of bugs, providing an infinite profit by controlling insect populations.

There’s a variety of research about how most individuals get their science information from casual studying, reminiscent of at museums. How did your museum expertise differ from working in academia, and the way has it affected your profession?

It looks as if there’s a disconnect between lecturers and most people. That’s the position that I believe pure historical past museums are ideally suited to play, to attach the teachers, the scientific message, with most people. These casual mechanisms for science training are ideally suited to take very advanced scientific ideas and translate them in a approach that most people can perceive and respect—and hopefully perceive how these ideas are connecting with their on a regular basis lives.

So all through my profession, I’d been doing work in museum collections. When this museum job got here up, I felt like this job was an ideal match for me.

Do you handle a group?

Sure, two collections. Once I began on the museum in 1998, I used to be employed because the entomologist. I in a short time satisfied them that I ought to add curator of bugs and spiders to my title. Then I grew to become division chair for a number of years and was capable of rent an entomologist. The 12 months after I joined the museum, I began up the arachnology assortment. We didn’t have an arachnology assortment in 1998. We’ve grown to about 50,000 or 60,000 vials. The info from 40,000 of them are on-line and extensively accessible. At one level I used to be curating that assortment and the entomology assortment, in addition to a marine invertebrate assortment, which was largely a shell assortment. That was a bit an excessive amount of. I employed an entomologist. However now I curate the arachnology assortment and the marine invert assortment. And from the very starting I made certain that each one the info from each these collections is accessible on-line. They’re printed and pushed out to the International Biodiversity Data Facility so the world can see our information, which has helped by way of growing entry and mortgage exercise.

How are camel spiders, or Solifugae, totally different from different spiders?

They’re arachnids, which means they’re within the class Arachnidae however in their very own order. There are 12 orders inside that class. Spiders are the order Aranea. Solifugae are their very own order. There are 12 totally different households. My lab is concentrated totally on a kind of 12 households that’s discovered from southern Canada all the way in which down by way of southern Mexico, the Eremobatidae. There’s in all probability 4 households which can be present in North and South America. They’re discovered primarily in xeric [dry], semi-xeric, or desert environments. They’re prime predators in these environments. As a result of they’re restricted to these habitats, they’re typically an indicator of the well being of these environments whether or not that’s true or not. Camel spiders seemingly diversified as these desert environments themselves got here to be. Because the desert environments diversified, you see a diversification of those desert-adapted species.

By understanding the variety and pure historical past of Solifugae, you possibly can typically translate that into a greater understanding of how these desert environments advanced. I work intently with one other colleague, Matt Graham, who’s a biogeographer at Japanese Connecticut State College, and he’s this precise marriage between solifugid variety and the evolution of those desert habitats. My lab is doing the molecular work and the morphological work to search out out the place the species boundaries are.

Solifugids don’t seem like typical spiders. How do you describe them?

The explanation that they’re within the class Arachnida is that they have sure morphological options in widespread with different arachnids. Their jaws are known as chelicerae. The construction of the jaws is similar to what you see in all the opposite arachnid orders. Like all arachnids they’ve 4 pairs of legs. They’ve a pair of entrance appendages known as pedipalps. They’ve two main physique elements, not three. They don’t have any antennae. All of these traits unite them with different orders of the category Arachnida.

However by way of what they seem like, they’re form of a cross between a weird-looking spider and a scorpion. However they’re their very own beasties.

The smallest grownup could be possibly a centimeter, as much as about six to 10 centimeters. Fairly massive. The biggest species are discovered within the Center East.

The place they fall by way of which of the opposite orders is their closest relative is anyone’s guess. There are research that place them as intently associated with pseudo-scorpions. Different research place them as extra intently associated with one lineage of acarines, of mites. Totally different colleagues are wanting on the greater stage relationships between these totally different orders of arachnids. That’s not my work in any respect. However with each totally different information set that’s used, the position of solifugids appears to shift. We don’t actually know who they’re most intently associated to and what their ancestor might have seemed like proper now. That’s nonetheless a transferring goal.

How did you start learning the Solifugae, these camel spiders?

Once I acquired my job on the museum in 1998, one way or the other both I came upon {that a} man named Jack Burkhardt—who’s been publishing on camel spiders because the Sixties—lived in Denver, or he came upon that there was an arachnologist on the museum, or each. Neither certainly one of us can work out precisely how we related. However he contacted me. I knew his identify from the literature. He stated he was taken with working within the assortment. After all, I used to be very welcoming of that, as a result of I knew he was a world professional on this group of arachnids.

Jack is now in his late 80s. He’s an excellent scientist, very educated about camel spiders, and a delicate soul. He’s additionally very persuasive. When he first began coming into my lab, at first he stated, ‘Effectively, let’s collaborate. I don’t draw effectively, so why don’t you draw the diagrams and the morphological figures, in order that I can proceed my taxonomic work?’ And so I began illustrating his publications. Then he stated, ‘Effectively, you’re a scientist, so why don’t you assessment these papers and put in your 25 cents value of enter?’ I grew to become a extra energetic collaborator. Then we came upon that there was one other colleague who was engaged on an enormous NSF [U.S. National Science Foundation] grant targeted on camel spiders. I wrote to that colleague and stated, ‘Hey, we’re doing all this taxonomic work. We should be plugged into this grant.’ I grew to become co-PI [co-principal investigator] of that grant, and Jack was instrumental in that grant. That was a five-year NSF grant. I acquired a four-year NSF grant to proceed our work. That second grant I largely acquired as a result of I used to be capable of say, ‘There’s one world professional, Jack Burkhardt. He’s in his 80s. We have to get extra individuals into this subject, extra college students educated up underneath Jack, earlier than we lose his wealth of information.’ That was a big a part of why I managed to get the second grant. That’s how I acquired into camel spiders.

Jack by no means instructed me how brutally laborious camel spiders had been to work on. They’re laborious to gather, laborious to search out, and unimaginable to maintain alive within the lab. We’ve discovered that any time we write up a manuscript, we have to clarify within the introduction that these are horrible animals to work with. You’re fortunate in case you get 5 animals on an evening of eight hours of subject work. That’s an excellent evening. We have now to preface the paper with all of this data. You’ll be able to’t preserve them alive within the lab, and that’s why our N worth [sample size] is 10 and that’s it. As a result of in any other case the peer reviewers, who’re largely arthropod individuals, say, ‘Why didn’t they’ve extra?’

You stated solifugids are prime predators of their environments?

Solifugids consider nothing however meals. They’ve an excellent excessive metabolic fee. Largely they’re nocturnal. They solely come out of their underground hiding holes or burrows within the night after sundown. Then they’re searching from sundown till dawn. They transfer by way of the setting at very speedy paces. After they encounter an insect or one thing smaller than them—it could possibly be one other solifugid—they seize it with their pedipalps, convey it to their jaws, tear it aside, after which devour it. Then they’re on to search out the following factor to eat. They’re actually energetic predators they usually eat something. They eat ants. They eat one another. If they might, they might eat scorpions. There are documented circumstances of scorpions consuming solifugids and solifugids consuming scorpions.

So solifugids don’t construct webs or anticipate prey to return to them, as spiders do?

Right. They’re very energetic predators. Actually, that top exercise stage is actually uncommon for arachnids. Most arachnids are sit-and-wait predators with a really low metabolic fee, even ones which can be energetic hunters like wolf spiders, which might do a fast run to take down prey, however then they should cease. Metabolically they only can’t maintain that top exercise stage for very lengthy. Similar factor with scorpions: Scorpions come out of their burrows and simply anticipate one thing to stroll previous.

All these different arachnids have fairly low metabolic charges, however not solifugids. We’re not likely certain why that’s. I’m working with one other colleague who’s a physiologist to attempt to perceive extra about how they will preserve this excessive metabolic fee and maintain it for therefore lengthy. I had a colleague, Yael Lubin, who as soon as adopted a solifugid within the Negev Desert in Israel. She stated she adopted it for over an hour to see how lengthy it took earlier than the solifugid stopped and needed to relaxation. It by no means did. It simply constantly moved by way of that setting. It’s extra like a flying insect’s metabolic fee than some other arachnid. Very uncommon.

What did you discover out in regards to the biogeography of the Solifugae?

In a paper we printed in 2015, Matt Graham demonstrated we may have a look at the timing of once we suppose totally different lineages of Solifugae appeared within the setting, and will mainly match that to when these habitats had been approaching the scene as effectively. Because the glaciers retreated and desert habitats began appearing in North America, you see a concurrent diversification and growth into these new habitats of those desert-adapted arthropods, together with Solifugae.

Matt has additionally accomplished some subject work within the Baja Peninsula with my college students final 12 months. They know what the hypothesized evolution of that peninsular habitat is, and that it was inundated by inland seas and divided up into a number of totally different islands. Then, because the seas dissipated, the peninsula appeared. He’s been capable of present in very latest work that this look matches the genetic diversification of some solifugids in these totally different elements of the peninsular habitat of the Baja Peninsula. That matches fairly effectively with what we take into consideration how that peninsula itself advanced.

You stated they couldn’t dwell within the lab very effectively. Is that due to the circumstances they usually dwell in?

No thought. There are a variety of points of their pure historical past that we simply don’t perceive. It might be that there’s a really slim vary of temperature and humidity that permits them to dwell. What appears to occur is whenever you convey them into this synthetic lab setting, they only—I don’t know methods to say it besides anthropomorphically—they only appear to offer out. I’ve had ones run across the circumference of a cage till it lastly simply dies. It had a bit of coronary heart assault and died. They simply don’t like being in captivity. Perhaps you possibly can preserve them alive for a month, and that’s fairly good. However often they die inside every week or two. And that additionally could possibly be that their life span as adults may simply be fairly quick. We simply don’t know sufficient about them to know.

To different tasks, how did you find yourself learning orb weaver spiders in area?

There’s this nice firm in Boulder, Colorado, known as BioServe Area Applied sciences. BioServe works very intently with NASA. It’s a form of conduit between lecturers and NASA in growing life science experiments that may be packaged and transported as much as the Worldwide Area Station (ISS). If a scientist or anyone else has an thought about one thing they need to ask about area environments that has to do with worms or fruit flies or spiders or any form of life sciences, BioServe has sufficient expertise that they will work with the scientist, get an understanding of the speculation, after which develop the protocol and the tools required to move that experiment safely as much as the ISS. And so years in the past, I believe it was when the Columbia explosion occurred, BioServe had been working with a highschool pupil who wished to ship orb weaving spiders as much as area. This had already been accomplished since Skylab again within the Seventies. They simply wished to repeat this experiment utilizing orb-weaving spiders. They discovered that there was a spider biologist, an arachnologist, within the state. They’d despatched the experiment up on Columbia.

They had been making an attempt to restructure the habitats and requested to fulfill with me to go over the plans for the redesign. So, we met, and I went over that spiders want a prepared provide of water. They’re water restricted, not meals restricted. So long as they’re well-fed whenever you ship them up, they need to be wonderful for some time, however not in the event that they don’t have water. And so we designed the habitat that will enable them to get a drink of water. Then I pulled in one other colleague, however by that point it was November, in order that they had been solely capable of ship juveniles of Colorado species. However I contacted a colleague who lives in Florida and he was capable of ship some wild-caught grownup spiders, orb weavers of a special species, which can be sufficiently small to slot in a really small habitat.

That’s how I acquired concerned, serving to them design the habitat. Then I acquired to go to the launch. I acquired to be concerned within the handoff the place we did the ultimate preparation of the habitats, after which the NASA personnel come into the laboratory all wearing scrubs. The scientist palms off the experiment to the NASA personnel. At that time we will’t contact it anymore as a result of it must be sterile. That was simply so thrilling. Who would have thought I’d be concerned in that? I acquired to go to the VIP viewing platform to look at the launch. The concept one thing I touched was flying as much as the ISS was simply&mdasy;oh my God—that was a spotlight of my profession.

Later, I helped them with one other experiment to ship leaping spiders as much as area, and one other experiment to ship a special form of orb-weaving spider as much as area, known as Nephila. Then I used to be capable of join BioServe with colleagues who had been capable of do some information evaluation and truly get a few of these information from two of the orb-weaving experiments. One in all my colleagues, Samuel Zschokke, was capable of take the info and get it printed. I used to be on that paper. I used to be capable of join BioServe with someone who focuses on spider webs and internet development. Then there’s a professor, a robotics professor at College of Colorado Boulder, Kaushik Jayaram. He has a pupil who’s actually taken with leaping spider conduct and the mechanics of leaping spider conduct. I’ve related him with BioServe in order that his pupil can analyze the info from the leaping spider experiment. Hopefully sometime we’ll have the ability to get these information on the market and get it printed as effectively.

I really feel like I’m extra of a connector between BioServe and my colleagues, who I do know have the capability and the potential to do the fine-tuned evaluation of conduct. I don’t have that experience.

Have been there any surprises popping out of those research in area?

When BioServe despatched these habitats up there, with a purpose to take footage of the habitats, they needed to be illuminated. They’d it on a 12-hour mild, 12-hour darkish cycle, and naturally the lights had been shining down on the net from the identical course daily.

What Samuel was capable of doc is that on Earth spiders use gravitational cues to know methods to orient of their internet and place themselves on the net and methods to construct the net. In area, what they had been utilizing is the sunshine cues. The gravitational cues had been nonexistent, however the spiders had been capable of exchange the gravity cues with mild cues. When the lights had been off, the spider was each which approach on the net. However when the lights had been on, they had been at all times going through downward like they might on Earth. They had been capable of adapt to this setting. We knew they might adapt to lack of air present and lack of gravity cues and nonetheless construct absolutely practical webs.

For leaping spiders, they’re nonetheless capable of hunt. For the orb weavers we knew they’d have the ability to try this, as a result of we’d seen that in Skylab. And we knew the construction of the net was extra even. On Earth there are extra seize spirals beneath the hub than above the hub. In area it’s extra symmetrical. The hub is kind of proper within the center. And there are another refined variations. In area the spiders are capable of simply carry the silk from level A to level B, as a result of they don’t have any air currents to depend on to hold the silk. However what we didn’t know is they might use these mild cues within the absence of different cues. They may exchange the gravity cues with mild cues and know methods to orient themselves. That’s fairly cool.

One final query: What has come out in your analysis on ant-spider symbioses?

I’ve checked out spiders that both are ant specialists, feeding simply on ants, or that dwell in very shut affiliation with them, generally inside ant nests. In my spider line of analysis, I attempt to perceive how spiders cross that species boundary, how they turn into built-in with this very advanced social dynamic that’s represented by ant colonies.

One in all my colleagues, Norm Horner, is an unimaginable naturalist who’s in his late 70s. Norm has been on the market within the Huge Bend space of Texas. Years in the past, certainly one of his college students found a spider that none of us may establish. It was simply weird, a tiny little factor. Weird morphology. He despatched it to me, in addition to a number of colleagues all around the world. None of us may even establish the household.

A colleague in 2019 lastly acquired some specimens, ran a DNA evaluation, and located that it got here out as its personal lineage. There have been many authors on that paper. Martin Ramirez, my colleague who did the molecular work, positioned this spider in its circle of relatives.

We knew it was a very uncommon spider. Norm had solely discovered it in affiliation with ant nests. He and I went down throughout the pandemic to Huge Bend. We had been pondering it is a spider—like a number of different species which have been documented—that’s in all probability residing inside ant colonies. It’s in all probability consuming different little arthropods that dwell within the ant colonies.

We wished to search out out extra in regards to the pure historical past of this very weird spider. We went all the way down to Huge Bend and managed to gather two dwell spiders proper subsequent to a nest. We introduced these dwell spiders again to the laboratory in Huge Bend. We launched them to a Petri dish with a number of ants from that very same colony, including the ants to the dish the place the spiders had been hiding, and lo and behold, what do we discover out? These spiders are ant eaters. They specialise in searching ants, which nobody had identified about their biology earlier than. We had been capable of movie them dashing up behind the ants, biting the ant’s rear leg, backing off, ready till the ant succumbed to their venom, re-approaching, grabbing the ant behind its head, carrying it off, after which if a dwell ant approached the spider that was holding on to the lifeless ant, the spider would maneuver its physique and twist round in order that it was presenting the lifeless ant to the residing ant as a protect. This type of conduct had been documented for different specialist ant predator spiders, spiders in a household known as Zodariidae, which additionally specialise in searching ants. Virtually equivalent searching conduct. It’s clear that this very totally different lineage has advanced very related searching methods when searching such a harmful prey. We had been capable of get sufficient information to investigate it and to submit it to the Journal of Arachnology.

Now we need to discover out if the spider resides within the neighborhood of the nest, which is what I believe is occurring. However Norm thinks they really dwell contained in the colonies. If that’s the case, that’s form of weird. You’re speaking about mainly an ant assassin that lives amongst its personal prey. That may be completely weird.