# Ep 219 The Brown Recluse: Fearsome foe or slandered spider?

An episode of [This Podcast Will Kill You](https://invisiblenetwork.ai/podcast/1299915173), 18 Aug 2026, 59 min.

Audio: https://podtrac.com/pts/redirect.mp3/traffic.omny.fm/d/clips/e73c998e-6e60-432f-8610-ae210140c5b1/e0709a39-232b-4483-8e4f-b24c0111ae2c/3d3f4c8d-b3ad-48bb-9bbc-b4a301513369/audio.mp3?utm_source=Podcast&in_playlist=64b4c224-562e-4b2f-9f31-b24c0111ae53

Few spiders hold the dubious honor of name recognition among the general public. Most that do, like black widows, Australian funnel-web, the Goliath birdeater, are renowned not for their cute colors or weaving skills but for being fearsome, dangerous predators. The brown recluse is no exception. A bite from one of these arachnids can send someone to the hospital with a painful necrotizing wound and weeks of recovery. But do these spiders actually deserve all the hatred they get? In this week’s episode, we argue no. Breaking down not just the bite of thebrown recluse but also its behaviors, its distribution, and its lore, we present a more complete picture of this vilified arachnid. Tune in for the low down on this shy spider. Support this podcast by shopping our latest sponsor deals and promotions at this link: https://bit.ly/3WwtIAu See omnystudio.com/listener for privacy information.

## Transcript

[0:00] Speaker 1: Missus CS, aged twenty four, entered the hospital because of
[0:03] Speaker 1: a spider bite on the ulnar side of the right
[0:05] Speaker 1: elbow and a rash over the entire body, with the
[0:08] Speaker 1: exception of the face. She stated that while riding in
[0:11] Speaker 1: an automobile November fifth, nineteen twenty eight, she suddenly felt
[0:15] Speaker 1: a sticking sensation on her right elbow. She removed her coat,
[0:18] Speaker 1: ran her hand into the sleeve, and withdrew a small object,
[0:21] Speaker 1: which dropped to the floor of the car and which
[0:24] Speaker 1: when recovered, was found to be a rather small taan spider.
[0:28] Speaker 1: Her arm began to pain at once, the pain becoming
[0:31] Speaker 1: progressively worse. On returning home an hour later, she examined
[0:35] Speaker 1: her arm and found a dark red spot surrounded by
[0:38] Speaker 1: an area of pallor. She slept well until three am
[0:41] Speaker 1: without a sedative, when she awakened with pain in her
[0:44] Speaker 1: right arm and a generalized rash which was most pronounced
[0:47] Speaker 1: on the abdomen and back. Her arm at this time
[0:50] Speaker 1: was aching and had swollen somewhat. The next day, the
[0:54] Speaker 1: swelling was very pronounced. Four days later, the rash seemed
[0:57] Speaker 1: to be fading, but the following day it was as
[0:59] Speaker 1: bad before. Before entering the hospital. The patient had a
[1:03] Speaker 1: rapid pulse, but her temperature reaction was mild, never much
[1:06] Speaker 1: over one hundred degrees fahrenheit. She entered the hospital five
[1:10] Speaker 1: days after having been bitten. The patient was anxious and restless.
[1:14] Speaker 1: The arms, legs, abdomen, and chest were covered with a
[1:16] Speaker 1: scarletiniform rash with a few small pustules on the legs.
[1:20] Speaker 1: On the inner surface of the right elbow was found
[1:22] Speaker 1: a small reddened area with a yellow center resembling a
[1:26] Speaker 1: small pustule. The area around the elbow was swollen and tender.
[1:30] Speaker 1: The entire abrasion was not more than one fourth inch
[1:32] Speaker 1: in diameter.
[1:33] Speaker 2: The treatment was.
[1:34] Speaker 1: Essentially palliative, consisting of sedatives internally and starch and sodium
[1:38] Speaker 1: bicarbonate baths. A solution of point five percent lead acetate
[1:42] Speaker 1: was used in wet packs applied to the area of
[1:44] Speaker 1: the bite. The spider was identified by Professor C. R.
[1:47] Speaker 1: Crosby of Cornell University as the specimens of Loxicele's refessens,
[1:52] Speaker 1: a species usually found in Texas, Florida, Mexico, Costa Rica, Europe,
[1:56] Speaker 1: and Japan. As Yet, little reference has been made in
[1:58] Speaker 1: the literature regarding its toxicity. So far as my search
[2:01] Speaker 1: of the literature enables me to judge, no case of
[2:04] Speaker 1: poisoning from its bite has been reported from this region.
[2:53] Speaker 2: Well well, well, well, well, well how about it?
[2:58] Speaker 1: How about that.
[3:01] Speaker 2: That was excerpted from a paper in nineteen twenty nine
[3:06] Speaker 2: by the by a doctor lf Schmouse and it's called
[3:12] Speaker 2: case of a rachnoidism spider bite, spider bite in jama
[3:16] Speaker 2: And this is what a lot of papers point to
[3:18] Speaker 2: as the first likely reported scientific clinical case study of
[3:24] Speaker 2: a bite from a brown recluse. And if you are
[3:27] Speaker 2: a spider nerd and you heard the scientific name in
[3:31] Speaker 2: the first hand locks of Cell's refesseens, that I think
[3:34] Speaker 2: is what it initially was called before they changed it
[3:36] Speaker 2: to reclusa. I don't know the timeline.
[3:39] Speaker 1: There's also there's another species that's like the Mediterranean recluse
[3:43] Speaker 1: that's like refusines now today, So like who knows which
[3:47] Speaker 1: species it actually was at the time, but right they're similar.
[3:50] Speaker 2: But yeah, yeah, there you go. So we go. Hi.
[3:54] Speaker 2: I'm Aaron Welsh and I'm Erin alman Updite and this
[3:57] Speaker 2: is this podcast will kill you.
[3:59] Speaker 1: Today we're talking brown recluse bites. We are I'm really
[4:05] Speaker 1: excited about this.
[4:06] Speaker 2: Actually you too. It's so interesting how large the fear
[4:13] Speaker 2: looms in many places and infamous I think is like
[4:19] Speaker 2: that's a correct I think, yeah, that's a correct and
[4:21] Speaker 2: like I can't wait to tell everyone how undeserved the infamy. Really. Yes,
[4:26] Speaker 2: we're going to dispel some myths here. We're going to
[4:29] Speaker 2: try to do a little bit of like reputational rehab
[4:31] Speaker 2: for these spiders, but also acknowledge that, like you know,
[4:35] Speaker 2: they as you will learn, the bite can be quite.
[4:39] Speaker 1: It can be bad. Yeah, it can be bad.
[4:41] Speaker 2: But there's a lot to cover. So you're excited. We
[4:44] Speaker 2: should finish our intro exactly.
[4:48] Speaker 1: First up, it's quarantin any time.
[4:50] Speaker 2: It is this week we are drinking a tangled web,
[4:54] Speaker 2: A tangled web. Yeah it is. Hold on, I wrote
[4:57] Speaker 2: in my notes because we picked this out cherry juice,
[4:59] Speaker 2: limed soda, water and marish, you know, cherry syrup.
[5:03] Speaker 1: A little bit reddish, a little bit bloody maybe.
[5:06] Speaker 2: Sure, sure, Yeah, it's delicious, it's refreshing, you know.
[5:11] Speaker 1: Check it out the full recipe on our website, This
[5:13] Speaker 1: podcast will kill you dot com and on all of
[5:15] Speaker 1: our social media channels. So make sure that you're following
[5:18] Speaker 1: us there if you're not already.
[5:19] Speaker 2: Yes, website has lots of good resources, including actual resources
[5:25] Speaker 2: for our Each episode transcripts links to various things like
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[5:35] Speaker 2: out for all of your This podcast will kill you needs.
[5:39] Speaker 1: Rate, review, and subscribe. We'd like to remind you. Shall
[5:43] Speaker 1: we get into this.
[5:44] Speaker 2: Let's do it after this quick break.
[5:59] Speaker 1: So to episode is not about all spiders by any means,
[6:05] Speaker 1: because spiders are incredibly varied. There are somewhere between forty
[6:10] Speaker 1: and fifty thousand species that we know of, and probably
[6:13] Speaker 1: another ninety thousand species we have yet to discover or name,
[6:17] Speaker 1: and they exist in every ecosystem on the planet except
[6:20] Speaker 1: for Antarctica, etc.
[6:23] Speaker 2: But what we are.
[6:24] Speaker 1: Talking about today is one specific spider, which is the
[6:29] Speaker 1: brown recluse loxo Cell's reclusa. Now, this is one of
[6:36] Speaker 1: a handful, literally just a handful of spiders that are
[6:40] Speaker 1: considered medically important. In fact, there are at least one
[6:44] Speaker 1: hundred related species of lox of cells. Many of the
[6:48] Speaker 1: venoms of these different los oficell species all act very similar.
[6:52] Speaker 1: So I'm going to focus on the brown recluse today.
[6:55] Speaker 1: Because this is like one of the most infamous spiders
[6:57] Speaker 1: aside from the black widow black widow, which I couldn't
[7:02] Speaker 1: remember the name of real quick in the US. I
[7:04] Speaker 1: feel like the black widow is like the most famous,
[7:07] Speaker 1: and then the brown recluse is also the most famous.
[7:10] Speaker 1: I feel like they're equal. Sure, I don't know, I
[7:13] Speaker 1: have no I don't have a statistic on that. Yeah,
[7:17] Speaker 1: but the brown recluse is actually not found in very
[7:19] Speaker 1: much of this country. It's really only found across the
[7:22] Speaker 1: south central US, from like the lower Midwest, like halfway
[7:26] Speaker 1: through Illinois and then down into the Gulf. It goes
[7:30] Speaker 1: as far east as like Tennessee and then as far
[7:34] Speaker 1: west as like just to the edge of Texas.
[7:37] Speaker 2: Kind of yeah, it's like not quite in Colorado, for example,
[7:41] Speaker 2: the very.
[7:41] Speaker 1: Edge not coldo. It's not here in California. There are
[7:46] Speaker 1: a few other species in the US. One that is
[7:49] Speaker 1: called blocks of Cell's deserta that is in like Arizona,
[7:52] Speaker 1: New Mexico and a little bit of California. And there
[7:56] Speaker 1: are a number of other species of again medical importance
[7:59] Speaker 1: throughout Central and South America, including Locoicelli's intermedia gaucho, Latia
[8:05] Speaker 1: and refusins, which is actually the Mediterranean spider that has
[8:08] Speaker 1: been invasive in a number of areas as well. So
[8:12] Speaker 1: all of these recluse species are these kind of smallish
[8:18] Speaker 1: brown spiders. There may be like one to two centimeters
[8:22] Speaker 1: in total including their legs. Some of the older ones
[8:25] Speaker 1: could get up to like three centimeters, so they're really
[8:27] Speaker 1: not large.
[8:28] Speaker 2: That's very small.
[8:29] Speaker 1: Yeah, yeah, I think we're going to have to find
[8:32] Speaker 1: some pictures to post of these two, so we will,
[8:34] Speaker 1: we will. But their legs are very long and slender,
[8:40] Speaker 1: and they don't have one of those real globe like
[8:43] Speaker 1: abdomens that we see in black widows. Their abdomen is
[8:46] Speaker 1: a bit more elongated, and their whole body, the cephalothorax,
[8:50] Speaker 1: the top part and the abdomen. They're quite a bit
[8:53] Speaker 1: flatter than other, like real hefty looking spiders, and they
[8:58] Speaker 1: tend to sit with their legs quite outright. They're not
[9:02] Speaker 1: all bent up, and that's because they like to hide
[9:05] Speaker 1: in teeny tiny little cracks and crevices, So they're really
[9:08] Speaker 1: a flatter spider than some big like you know.
[9:11] Speaker 2: Right tarantula looking right exact.
[9:16] Speaker 1: They can vary in color from a like lightish yellowy
[9:19] Speaker 1: brown to almost a gray, or as they get older
[9:24] Speaker 1: they darken, which I think is really interesting, so they
[9:26] Speaker 1: can be quite dark brown if they're an older spider.
[9:30] Speaker 2: Yeah, and they're.
[9:31] Speaker 1: Very famous for having this so called violin pattern on
[9:35] Speaker 1: their cephalothorax or fiddle or a fiddle, a violin or
[9:39] Speaker 1: a fiddle, so they're often called violin or fiddleback spiders.
[9:42] Speaker 1: I don't see a violin as hard as I try
[9:44] Speaker 1: in theory. It's like the neck of the violin points
[9:47] Speaker 1: towards their abdomen and the body of it is towards
[9:49] Speaker 1: their head. I don't think it looks like a violin
[9:52] Speaker 1: at all. And there's plenty of other spiders that have
[9:56] Speaker 1: similar like violin patterns, so really that's not a good
[9:58] Speaker 1: way to identify them. What is a good way to
[10:01] Speaker 1: identify them is that number one, their abdomen and their
[10:07] Speaker 1: legs are one color. They don't have patterns on their
[10:10] Speaker 1: abdomen or on their legs. So if you see a
[10:13] Speaker 1: spider that has a pattern on their belly or their
[10:16] Speaker 1: legs have speckles and splotches, that's not a round reckless.
[10:20] Speaker 1: And they have six eyes.
[10:23] Speaker 2: I have that as a fun fact.
[10:25] Speaker 1: So fun and they're arranged in three pairs, so they
[10:28] Speaker 1: have these two in the middle and then two on
[10:30] Speaker 1: either side. Is kind of cute and ridiculous sleeping, and
[10:34] Speaker 1: so that's how you can kind of identify them. They
[10:37] Speaker 1: make webs like pretty much most spiders, but they don't
[10:40] Speaker 1: make those beautiful like Charlotte's Web kind of webs like
[10:45] Speaker 1: or Siker type or weaverery types. In fact, they make
[10:48] Speaker 1: these really tangled, mish mush sheet webs that they use
[10:53] Speaker 1: to just kind of cover little cracks in bark or
[10:56] Speaker 1: under rocks or holes in the ground or maybe in
[10:59] Speaker 1: a pie of lumber in your backyard or bookshelf or
[11:05] Speaker 1: in your basement, whatever it is, and they can live
[11:08] Speaker 1: for a number of years.
[11:11] Speaker 2: That's another of my fun vats to talk about.
[11:16] Speaker 1: I won't say anything more.
[11:17] Speaker 2: Okay, no, no, it's okay, you can keep going.
[11:20] Speaker 1: That's not literally all I have arin that's the spiders themselves. Okay.
[11:24] Speaker 1: So the most important thing about spiders for humans is
[11:29] Speaker 1: that they make venom. All spiders make venom. And the
[11:34] Speaker 1: last time that we talked about venom was in our
[11:36] Speaker 1: Snake Venom episode.
[11:38] Speaker 2: Wow, yeah, a really long time ago to venoms.
[11:41] Speaker 1: I know, and to distinguish a venom from a poison,
[11:46] Speaker 1: which I feel like is important. A poison is a
[11:49] Speaker 1: toxic substance that's produced in nature, so by a plant
[11:52] Speaker 1: or an animal that usually can produce symptoms via any
[11:56] Speaker 1: kind of contact, so contact with mucus membranes or via ingestion,
[12:00] Speaker 1: whereas a venom is a specific type of poison that
[12:04] Speaker 1: is delivered via this specialized system where it has to
[12:06] Speaker 1: be injected. Okay, most venoms are used either for prey
[12:11] Speaker 1: capture or as self defense. Yeah, and while all spiders
[12:17] Speaker 1: have venom, and venoms are by no means unique to
[12:20] Speaker 1: spiders or even arthropod's, lots of animals make venoms. Spider
[12:25] Speaker 1: venom is really interesting because it can vary really widely
[12:29] Speaker 1: across the spiders all spiders, but in all of them,
[12:33] Speaker 1: they're housed in this specialized pair of appendages called the chiliserae,
[12:37] Speaker 1: which I think are very cute, and they're basically they
[12:42] Speaker 1: they I think people think of them as the fangs
[12:45] Speaker 1: because it's what sticks out from a spider's little face.
[12:48] Speaker 1: But if you think of like your hand as the
[12:50] Speaker 1: actual chilisra, and then your fingers are the fangs, fangs
[12:54] Speaker 1: sit tucked up underneath their chillisserae, and then the venom
[12:57] Speaker 1: glands are located in the chilisrae.
[13:00] Speaker 2: They have a duct that.
[13:02] Speaker 1: Goes down to the tip of the fang, and they're
[13:05] Speaker 1: surrounded by muscles and nerves, So the spider can actually
[13:07] Speaker 1: control how much venom it releases with each bite, or
[13:11] Speaker 1: whether it releases any venom at all.
[13:15] Speaker 2: Interesting mm hm.
[13:17] Speaker 1: And so basically, when a spider is ready to it
[13:19] Speaker 1: flicks its things out and then stabs them in and
[13:22] Speaker 1: then releases whatever type, whatever mixture of whatever amount of
[13:26] Speaker 1: venom they decide to do.
[13:28] Speaker 2: What are the things made of? Oh, I don't know.
[13:33] Speaker 2: Kit I don't know, I know, just like is it
[13:35] Speaker 2: specialized kiten? Like why, you know, how do they actually
[13:39] Speaker 2: penetrate human skin for instance, or you know, does it?
[13:43] Speaker 1: And yeah, that's a great question. I don't know. I
[13:47] Speaker 1: didn't look that much into detail of it. Most, I mean,
[13:49] Speaker 1: spider exoskeletons in general and made of mostly kiten, so
[13:52] Speaker 1: I imagine it's just like a specialized extra hard in kiten.
[13:55] Speaker 1: They do have to be large enough in diameter and
[13:58] Speaker 1: sharp enough to be able to penetrate human skin. Most spiders.
[14:01] Speaker 1: Their fangs are not sharp enough or large enough to
[14:03] Speaker 1: penetrate human skin.
[14:04] Speaker 2: Which is it is? And this is where I didn't
[14:06] Speaker 2: even get in. I didn't look into this at all.
[14:08] Speaker 2: But it's it's interesting to think about, like brown recluse
[14:11] Speaker 2: spiders being quite little. Yes, why why do they have
[14:15] Speaker 2: fangs that are capable can do that?
[14:17] Speaker 1: Yeah? It is interesting. Yeah, I don't have an answer
[14:19] Speaker 1: for that. Little little beetbops. I mean, black widows are
[14:22] Speaker 1: real small too, Yeah they are. Yeah, so I don't know, huh.
[14:27] Speaker 2: But then similarly sized or larger spiders don't.
[14:30] Speaker 1: Don't necessarily yes, or maybe their venom is just not as.
[14:34] Speaker 2: Part their venom is not as poet right, I mean,
[14:37] Speaker 2: can penetrate spider bites? Yeah?
[14:38] Speaker 1: Yeah, So let's talk about the venom of the brown recluse,
[14:42] Speaker 1: shall we.
[14:43] Speaker 2: Let's do it.
[14:44] Speaker 1: It is a lot like there are a lot of
[14:48] Speaker 1: different enzymes contained in this venom. It is not just
[14:51] Speaker 1: one thing, but the most important of which we think
[14:55] Speaker 1: for human like the kinds of symptoms that we see
[14:58] Speaker 1: from a human bite is called sphingle myelinase D, which
[15:03] Speaker 1: is just one type of enzyme. But what it does
[15:06] Speaker 1: is it attaches to our cell membranes, especially on our
[15:09] Speaker 1: red blood cells, but also on our endothelial cells, so
[15:14] Speaker 1: that's the cells that line our blood vessels and lots
[15:16] Speaker 1: of other cells kind of indiscriminately. And what it does
[15:19] Speaker 1: is disintegrate these cell membranes, so it causes our cells
[15:23] Speaker 1: to lice and break open. That not great, and that
[15:28] Speaker 1: in our body is going to cause the release of
[15:30] Speaker 1: a huge amount of inflammatory markers. Right, It's going to
[15:33] Speaker 1: stimulate our immune system because we're like, why are our
[15:36] Speaker 1: cells breaking open. It's also going to trigger our clotting cascade,
[15:41] Speaker 1: which see our hemophilia episode for all the details on.
[15:45] Speaker 2: That four or five years ago.
[15:47] Speaker 1: Who knows lost is not more? And so what this
[15:50] Speaker 1: means is that things like our red blood cells are
[15:53] Speaker 1: being hemalized, they're breaking open, the stuff that's in our
[15:56] Speaker 1: red blood cells are spilling out, and our clotting cascade
[16:01] Speaker 1: is being activated. And so this can cause both bleeding
[16:06] Speaker 1: and a coagulopathy, so blood clots that can form. So
[16:10] Speaker 1: then what we can see is surrounding the area of
[16:14] Speaker 1: the bite where this venom has penetrated, we can see
[16:16] Speaker 1: tissue death or necrosis. And as this venom diffuses through
[16:20] Speaker 1: our bloodstream. We can see more serious symptoms depending on
[16:24] Speaker 1: kind of how far it goes and how rampant the
[16:27] Speaker 1: immune response really is.
[16:29] Speaker 2: And does that depend on location of bite. It's such
[16:33] Speaker 2: a good question.
[16:34] Speaker 1: It probably depends on a lot of different things, the
[16:37] Speaker 1: location of the bite, how much venom was injected, or
[16:40] Speaker 1: whether venom was injected at all. And I tried to
[16:42] Speaker 1: get a sense of like how much venom does a
[16:44] Speaker 1: spider bite give you? And I couldn't. I don't know
[16:48] Speaker 1: if you found that anywhere. I found one paper that
[16:51] Speaker 1: said that the approximate amount of venom per bite was
[16:53] Speaker 1: two thousand nanograms, but the citation on that was like
[16:56] Speaker 1: a personal communication with some dude who raises spiders.
[17:00] Speaker 2: Also, like that number has no meaning, It has.
[17:02] Speaker 1: No meaning, exactly like how many millileaters?
[17:05] Speaker 2: I have no idea.
[17:06] Speaker 1: It's a very very small amount, right, this is a
[17:09] Speaker 1: teeny spider. It's injecting a very small amount, but it's
[17:11] Speaker 1: very potent venom, right, So it's going to depend probably
[17:14] Speaker 1: on the amount, on the location, on the age of
[17:18] Speaker 1: the person. So kids seem to be more adversely affected
[17:21] Speaker 1: than adults when they get bitten, And then probably other
[17:25] Speaker 1: things too, especially when we talk more about the symptoms.
[17:27] Speaker 1: If you have something like diabetes, that's going to delay
[17:30] Speaker 1: your wound healing to begin with. Right, So there's going
[17:32] Speaker 1: to be a lot of individual factors that play into
[17:34] Speaker 1: how bad this bite ends up being. And the thing
[17:38] Speaker 1: is that as scary as that venom sounds, right, this
[17:40] Speaker 1: venom is diffusing into your skin and blood vessels and
[17:45] Speaker 1: disintegrating cells as it goes. It sounds pretty bad.
[17:48] Speaker 2: I just leave in a trail of destruction. Right.
[17:52] Speaker 1: You are so unlikely to be exposed to this venom, right, Yeah?
[17:57] Speaker 1: Because first of all, these spiders are nocturnal. They're not
[18:00] Speaker 1: out and about wandering around when we are. They're holed
[18:04] Speaker 1: up in teeny tiny cracks and crevices. They are not
[18:08] Speaker 1: aggressive spiders.
[18:10] Speaker 2: They're really not. These are reclose for a reason.
[18:13] Speaker 1: Right, They are really not aggressive. Like there are spiders
[18:15] Speaker 1: in Australia that will chase you around the room or
[18:18] Speaker 1: like rear up and attack you, and these spiders really don't.
[18:22] Speaker 1: They really really try to avoid contact with you, and
[18:26] Speaker 1: they will bite you if they are, for example, wrapped
[18:29] Speaker 1: up in your summer towels that you finally take out
[18:32] Speaker 1: and then wrap yourself around in and they get squished
[18:35] Speaker 1: between you and a towel. Those are the kinds of
[18:37] Speaker 1: situations that they bite with in. Yeah, but despite their
[18:42] Speaker 1: quiet nature, their venom can pack quite a punch, so
[18:46] Speaker 1: it's often called necrotic aracnetism or gangreno cutaneous aracnism, or
[18:53] Speaker 1: even lucks of sellism. Yeah, I've seen that a lot
[18:56] Speaker 1: when you get envenomated by a brown recluse, And most
[19:01] Speaker 1: of the literature kind of splits the array of symptoms
[19:04] Speaker 1: that we can have into four kind of categories. One
[19:08] Speaker 1: is no symptoms at all, One is minor injury. I
[19:12] Speaker 1: guess that's number two. Three is like a slightly worse
[19:16] Speaker 1: skin lesion that may leave a scar. And then finally
[19:20] Speaker 1: you can have systemic symptoms. So we can kind of
[19:22] Speaker 1: go through all of those. Often the bite itself is
[19:26] Speaker 1: not necessarily painful, which can mean that it's hard to
[19:29] Speaker 1: know right away if you got bitten. You don't necessarily
[19:32] Speaker 1: feel the moment that those fangs puncture your skin. But
[19:36] Speaker 1: usually within a few hours of a bite, you might
[19:38] Speaker 1: see redness or swelling, and you might have a kind
[19:42] Speaker 1: of burning pain or itching, not dissimilar to any other
[19:46] Speaker 1: insect bite. Really and then at some time over the
[19:50] Speaker 1: next few hours or couple of days, you might see
[19:54] Speaker 1: a central area of kind of necrotic tissue or this
[19:58] Speaker 1: dead kind of tissue that starts to deve. It might
[20:01] Speaker 1: look just like a kind of duskier color that doesn't
[20:06] Speaker 1: necessarily look like dead skin. It's just sort of like
[20:08] Speaker 1: a duskier color with like a reddish ring around it.
[20:12] Speaker 1: Or it could look like kind of a blood blister
[20:14] Speaker 1: in the center.
[20:15] Speaker 2: These are all googleable pictures if you would like to see
[20:18] Speaker 2: for yourself.
[20:19] Speaker 1: Just although so many pictures on Google are like, probably
[20:22] Speaker 1: not actually a brown recluse bite.
[20:24] Speaker 2: Wow, yeah, that is also the story of brown recluse.
[20:28] Speaker 1: And then this can progress to basically like a necrotic
[20:32] Speaker 1: area of tissue that's usually really well defined and then
[20:36] Speaker 1: surrounded by redness, which depending on the area, could spread
[20:39] Speaker 1: like a good ways up say your arm or something,
[20:42] Speaker 1: over the course of a few days, or it might
[20:44] Speaker 1: just be right around where that wound is. And even
[20:48] Speaker 1: though this can result in an ulcer that eventually kind
[20:51] Speaker 1: of sluffs off and takes quite some time to heal,
[20:56] Speaker 1: it generally will heal on its own even without any
[21:00] Speaker 1: major medical interventions and I think it's easy for us
[21:03] Speaker 1: to hear the word necrotic tissue and think that's really bad,
[21:06] Speaker 1: I'm going to need surgery, et cetera. But it's usually
[21:08] Speaker 1: just the first couple of layers of skin and that
[21:11] Speaker 1: like a little bit of dermis that gets affected, and
[21:14] Speaker 1: so this usually heals completely on its own.
[21:16] Speaker 2: It's interesting. I was going to ask about, like, which proportion,
[21:20] Speaker 2: you know, how do all bites fall into these different
[21:23] Speaker 2: categories of no, you know, minor symptoms, et cetera. But
[21:28] Speaker 2: I would imagine that it's really difficult to get accurate
[21:30] Speaker 2: numbers given how many bites are misdiagnosed or how many
[21:35] Speaker 2: you know, wounds are misdiagnosed as brown recluse bites.
[21:38] Speaker 1: Yes, the number that I saw over and over in
[21:40] Speaker 1: the literature. And I don't know how they came up
[21:42] Speaker 1: with this, but they said that ninety percent of the
[21:44] Speaker 1: time there's like no need for medical intervention at all.
[21:47] Speaker 2: So it's only ten.
[21:48] Speaker 1: Percent of the time that a bite from a brown
[21:50] Speaker 1: recluse would need some kind of medical intervention. And even
[21:52] Speaker 1: that doesn't necessarily mean it's severe. It might just mean
[21:54] Speaker 1: wound care. Right, Yeah, there can be more systemic symptoms
[21:58] Speaker 1: like was described in our stand account. This like generalized rash,
[22:03] Speaker 1: This like red, splotchy, little little bumpy kind of rash
[22:07] Speaker 1: that almost looks like an allergic reaction or something. Even
[22:11] Speaker 1: that is usually self limited, so even that you usually
[22:14] Speaker 1: don't necessarily need to seek medical care or people don't
[22:16] Speaker 1: need a lot of medical intervention. However, there can be
[22:20] Speaker 1: more severe systemic symptoms from a brown recluse bite. As
[22:25] Speaker 1: this venom diffuses through the bloodstream and causes this immune
[22:28] Speaker 1: system activation and the hemolysis, the breaking open of our
[22:31] Speaker 1: red blood cells. We can start to see signs like fevers, chills, nausea,
[22:37] Speaker 1: or vomiting. People might show signs like jaundice and dark urine,
[22:42] Speaker 1: which means like massive level hemolysis or red blood cells
[22:45] Speaker 1: breaking open, and that eventually can lead to renal damage,
[22:49] Speaker 1: so kidney failure, even cardiovascular failure like edema in your
[22:54] Speaker 1: lungs which makes it really hard to breathe, and this
[22:58] Speaker 1: can In the literature it says lead to death. However,
[23:03] Speaker 1: as it we don't really know. Because there were eight
[23:08] Speaker 1: reported deaths in the US that were attributed to brown
[23:11] Speaker 1: recluse bites between nineteen eighty three and two thousand and four.
[23:15] Speaker 1: None of these were actually confirmed by spider identification. Okay,
[23:22] Speaker 1: there are reports in the literature of brown recluse bites
[23:25] Speaker 1: being fatal, but I couldn't find any that were like,
[23:29] Speaker 1: really really confirmed that there was a brown recluse. Either
[23:33] Speaker 1: we saw a bite or there was a spider recovered
[23:35] Speaker 1: shortly after these symptoms started, and that spider was identified
[23:38] Speaker 1: to be a brown recluse. Right, So it's a little
[23:41] Speaker 1: unclear if those systemic symptoms really were from a brown
[23:45] Speaker 1: recluse bite or not. And that's the thing that makes
[23:47] Speaker 1: this so hard. Yeah, it's really hard to definitively diagnose
[23:53] Speaker 1: a brown recluse.
[23:53] Speaker 2: Bite or any kind of spider bite, any spider bite
[23:57] Speaker 2: without having and like, you want to make the right diagnosis, right,
[24:02] Speaker 2: but how do you do that?
[24:03] Speaker 1: How do you do that? And technically to actually diagnose
[24:07] Speaker 1: a spider bite properly, you have to save the spider,
[24:10] Speaker 1: So you have to have the spider with you. That
[24:12] Speaker 1: spider needs to be identified by somebody who actually has
[24:15] Speaker 1: some degree of expertise in identifying spiders, because us as
[24:18] Speaker 1: the general public are really not good at it. There's
[24:20] Speaker 1: some interesting papers about people sending in brown recluses. Most
[24:24] Speaker 1: of them are not brown recluses, And a lot of
[24:27] Speaker 1: times you might not feel the bite initially, So if
[24:29] Speaker 1: you didn't witness the spider bite, or if you didn't
[24:32] Speaker 1: find a spider very close to you, or like in
[24:35] Speaker 1: your bed when you woke up with a bite or
[24:37] Speaker 1: something like that, it's really hard to directly connect those
[24:42] Speaker 1: two things. And there are so many other conditions that
[24:47] Speaker 1: can mimic.
[24:48] Speaker 2: These bites, my gosh, so many.
[24:49] Speaker 1: A staph infection, a strep infection, cutaneous anthrax, a vasculitis,
[24:53] Speaker 1: some kinds of cancers, atypical mycobacterial infections, diabetic ulcers, septic emboli,
[25:00] Speaker 1: other bites, and venom stings from other kinds of insects.
[25:04] Speaker 1: The list really does go on. And brown recluses are
[25:08] Speaker 1: not ubiquitous across this country, so they're often diagnosed in
[25:13] Speaker 1: areas that they don't even actually exist, which is wild
[25:17] Speaker 1: to me. Yeah, but because we don't learn the distribution
[25:20] Speaker 1: of spider species in med school, so just.
[25:23] Speaker 2: Right, you just learn about brown recluse bite.
[25:25] Speaker 1: Bron recluse bite. And so you see a thing and
[25:27] Speaker 1: you're like, and someone comes in and says, I think
[25:29] Speaker 1: this was a spider brighte spider bite. Yeah, right, so
[25:33] Speaker 1: it's they're really hard to diagnose. We also don't have
[25:35] Speaker 1: any like specific treatment or any specific diagnostics to be like,
[25:38] Speaker 1: can I identify brown recluse venom in your blood? We
[25:41] Speaker 1: don't have that. Yeah, And there's really no consensus on
[25:44] Speaker 1: how we actually treat this, so it's really just depending
[25:47] Speaker 1: on what someone's symptoms are what you're going to do
[25:50] Speaker 1: to treat it, which I think is interesting too.
[25:53] Speaker 2: Okay, let's say that you have some sort of necrotic
[25:56] Speaker 2: skin lesion. Does your course of treatment differ based on
[26:01] Speaker 2: whether that's caused by a spider bite versus something else?
[26:03] Speaker 2: I mean, yes, it could, but like it is kind
[26:07] Speaker 2: of interesting, like how I don't know, like does does
[26:10] Speaker 2: it right? When? When would you? I mean maybe if
[26:13] Speaker 2: it's like Mercy, you're using antibiotics and stuff exactly.
[26:15] Speaker 1: But like I think that's the biggest thing, is like
[26:18] Speaker 1: whether we need to use antibiotics If it's just a
[26:19] Speaker 1: spider bite, you probably don't, but it might really look
[26:22] Speaker 1: like something that you would want to use antibiotics for.
[26:25] Speaker 1: So it is it is it's one of those that
[26:27] Speaker 1: just is going to need monitoring, right right, right.
[26:31] Speaker 2: Did you say anything about immunity. I did not, did
[26:35] Speaker 2: you I did? I mean only minorly, And I don't
[26:39] Speaker 2: know if I actually wrote it down anywhere. But there
[26:41] Speaker 2: was a study that looked at exposure to like of
[26:45] Speaker 2: rabbits to spider bites, multiple spider bites. Okay, so they
[26:48] Speaker 2: did say, like, okay, yes, this can kill a rabbit.
[26:51] Speaker 1: Yes, but I have a lot of good animal studies
[26:53] Speaker 1: on the effects of the venom in animals.
[26:56] Speaker 2: Yeah, but then they also said that those rabbits that
[26:58] Speaker 2: did not die from this bite then re exposed tended
[27:01] Speaker 2: to have less severe reactions. Oh, that's so interesting. It
[27:05] Speaker 2: was also like it was not I don't think. I
[27:06] Speaker 2: don't think this was a recent paper, and I don't
[27:08] Speaker 2: think this was like a super It was just sort
[27:10] Speaker 2: of like disgusted. So I don't know the degree of
[27:14] Speaker 2: immunity or like whether that was demonstrated clearly or just suggested.
[27:19] Speaker 1: That's so interesting. Yeah, well, Aaron, that's brown recluses. Can
[27:24] Speaker 1: you tell me about these spiders and our long I
[27:29] Speaker 1: assume it's a long history with these although.
[27:31] Speaker 2: I don't know what is it. You know, that's a
[27:34] Speaker 2: great question. Okay, let's let's see what we can find out.
[27:53] Speaker 2: Brown reckless fighters, like we said, are infamous. They are
[27:57] Speaker 2: widely feared, they are hated, even I would say there
[28:01] Speaker 2: are not a small number of people who actively hate
[28:04] Speaker 2: not just not just brown cliders. But it is it
[28:09] Speaker 2: is fascinating that of the fifty three thousand or so
[28:11] Speaker 2: species of spiders on this planet, they're they are only
[28:15] Speaker 2: one of a handful with name recognition. We could probably
[28:18] Speaker 2: name a few other ones wolf spiders.
[28:20] Speaker 1: Wolf spiders. But does do you I feel like I
[28:22] Speaker 1: can say wolf spider. I don't know that I can
[28:24] Speaker 1: picture well, probably.
[28:26] Speaker 2: I think I can. Yeah, to rantle us, you know,
[28:29] Speaker 2: like but like for weavers or weavers, but then there
[28:32] Speaker 2: are different types of weavers, jumping spiders, like eye spiders.
[28:36] Speaker 1: They're my favorite.
[28:37] Speaker 2: They're very, very cute. But but yeah, these are these
[28:41] Speaker 2: are definitely one of the few celebrities of the spider world.
[28:46] Speaker 2: And based on what you told us, Aaron about these
[28:49] Speaker 2: painful necrotic wounds that their bites can cause, that fear
[28:54] Speaker 2: is understandable. Like I'm not going to say it's completely
[28:57] Speaker 2: unreasonable to fear spiders, but it is also out of
[29:01] Speaker 2: proportion to the actual risk that they pose. To most people. Yeah,
[29:05] Speaker 2: Like we said, if you compare a map of the
[29:08] Speaker 2: range of brown recluse spiders with one of diagnosed bites,
[29:13] Speaker 2: a bunch of those bites are well outside the range.
[29:15] Speaker 2: Like there was I think a paper that was describing
[29:18] Speaker 2: brown recluse bites in Colorado saying that they are common
[29:21] Speaker 2: seasonal currents and it's like they don't exist.
[29:25] Speaker 1: They don't exist here.
[29:27] Speaker 2: And if they if they do exist here, they're like transient.
[29:30] Speaker 2: And I'll get into why they're spread is not it's
[29:35] Speaker 2: not very likely, but anyway, they're scapegoats for a lot
[29:39] Speaker 2: of different things. Like you mentioned, there have been diagnosed
[29:43] Speaker 2: brown recluse bites that are actually strap chicken pox, diabetic ulcer,
[29:48] Speaker 2: chemical burns, syphilis, lime disease, Stephen Johnson syndrome, fungal infection,
[29:52] Speaker 2: and even in that two thousand and one anthrax bioterrorism
[29:55] Speaker 2: that's when it was misdiagnosed as a brown recluse bite.
[30:00] Speaker 2: That's wild and it didn't happen like the person who
[30:03] Speaker 2: who had this anthrax cutaneous anthrax did not live in
[30:07] Speaker 2: an area where brown recluse exists. But if you don't.
[30:11] Speaker 1: Have anyone who knows that on your medical team. Then why,
[30:16] Speaker 1: I mean, anthrax isn't exactly common either, so why would
[30:19] Speaker 1: that be the first thing that you think of, So like, yeah.
[30:22] Speaker 2: And this is it's sort of like it's like when
[30:24] Speaker 2: you hear hoof beats, you think horses, not zebras. But
[30:27] Speaker 2: I do feel like a lot of the time zebras
[30:29] Speaker 2: are brown recluse and everyone thinks zebras and don't thinks
[30:34] Speaker 2: don't think zebras.
[30:34] Speaker 1: And horses they're actually zebras.
[30:37] Speaker 2: Yes, yeah, but yeah, there's there's one report that I
[30:42] Speaker 2: thought was really interesting showed that of the six hundred
[30:44] Speaker 2: people they did like a survey who sought help for
[30:46] Speaker 2: a spider bite at hospitals in La and Arizona, eighty
[30:51] Speaker 2: percent of those bites were caused by other arthropods entirely,
[30:54] Speaker 2: So like not spiders, not spiders. But the reputation of
[30:58] Speaker 2: brown recluse spiders is these dead beasties just like laying
[31:01] Speaker 2: in wait to necross your limbs. That's actually a relatively
[31:05] Speaker 2: recent reputation that they got so reckless. Spiders were suspected
[31:10] Speaker 2: of causing necrotic skin lesions as early as the nineteenth
[31:13] Speaker 2: century in the medical literature. At least no doubt people
[31:16] Speaker 2: had made the connection long before and been like, spider
[31:19] Speaker 2: bite is not good, spider bite avoid no one, yeah,
[31:23] Speaker 2: no one, No one wants a spider wright. But the
[31:26] Speaker 2: brown reckless itself was first implicated in that nineteen twenty
[31:29] Speaker 2: nine case report that was in our first hand account,
[31:31] Speaker 2: that twenty four year old woman in Kansas who sought
[31:34] Speaker 2: medical care after being bitten. And in that case report,
[31:38] Speaker 2: like at the very end, he says the well, you know,
[31:41] Speaker 2: no case of poisoning from its bite has been reported
[31:44] Speaker 2: from this region. So that's that's not that long. It's
[31:47] Speaker 2: less than one hundred years ago. And occasional reports trickled
[31:52] Speaker 2: in in the years that followed, and nineteen fifty seven
[31:55] Speaker 2: is kind of when things really shifted. So a case
[31:59] Speaker 2: there was a case that confirmed that a bite from
[32:01] Speaker 2: locks of Cell's reclusa could cause necrotic scan lesions, so
[32:04] Speaker 2: that kicked off a slew of others. And you can
[32:08] Speaker 2: actually see the rise in how often the phrase brown
[32:11] Speaker 2: recluse was used starting in about nineteen sixty. So if
[32:14] Speaker 2: you're reused Google's and gram tool, it's like a tool
[32:20] Speaker 2: that shows you how often a certain word or phrase
[32:23] Speaker 2: or whatever is used over time. So you plot it
[32:25] Speaker 2: and it's like a little bump and then it's like
[32:27] Speaker 2: nineteen sixty, it starts to rise and it's like sotill.
[32:30] Speaker 2: Not very commonly used, but it is interesting. Suddenly the
[32:34] Speaker 2: world had begun to take an interest in this shy spider.
[32:38] Speaker 2: So nineteen sixty and beyond led to this uptick in
[32:42] Speaker 2: fear of this spider. But what else did we learn
[32:46] Speaker 2: in this time? I've got a few spider fun facts few,
[32:48] Speaker 2: I think I have a couple of remaining six eyes.
[32:51] Speaker 2: Got got that terrible vision their nests or not? They
[32:54] Speaker 2: had terrible vision, not very great. Their nests are not
[32:58] Speaker 2: super impressive. They can't balloon so the way other spiders
[33:02] Speaker 2: use their silk to like catch a breeze and they'll
[33:05] Speaker 2: traverse some distances. So if you think of spider's web,
[33:08] Speaker 2: I think Darwin even called them little aeronautsky something like that.
[33:12] Speaker 2: But this this actually keeps their potential for dispersal pretty low.
[33:16] Speaker 2: So when specimens are found outside of their typical range,
[33:19] Speaker 2: it usually means that they were transported by human activity.
[33:23] Speaker 2: So like here's a load of lumber, here's a shipping container,
[33:25] Speaker 2: here's whatever, and so is it likely for them to
[33:29] Speaker 2: get established in that new area? Also probably not based
[33:32] Speaker 2: on just environmental conditions. And so actually I found a
[33:36] Speaker 2: paper looking at what people think the distribution might shift
[33:40] Speaker 2: to as climate change happens, and that out it's north.
[33:43] Speaker 2: It doesn't. It's not range expansion, it's range just shift. Yeah,
[33:49] Speaker 2: let's see what else. They're super shy. Naturally, it's in
[33:52] Speaker 2: the name. But even among other brown recluses, there's not
[33:56] Speaker 2: a whole lot of aggression. Like, they're not social spiders
[33:59] Speaker 2: by any means. There are some spiders that are more social,
[34:01] Speaker 2: but they're not going to cannibalize each other if there's
[34:04] Speaker 2: if there's enough food to eat and enough crevices to
[34:07] Speaker 2: hide in, which is kind of interesting, they can grow
[34:11] Speaker 2: quite abundant within dwellings. So there's a there was a
[34:15] Speaker 2: house in Kansas that was two hundred and seventy meters
[34:19] Speaker 2: squared or about twenty nine hundred square feet, where two
[34:24] Speaker 2: and fifty five spiders were recorded over six months. So
[34:29] Speaker 2: one researcher caught more than eighty spiders in under an
[34:32] Speaker 2: hour by hand. Yeah. Yeah, so they do quite well
[34:39] Speaker 2: in human habitats, and sometimes you will find that in
[34:42] Speaker 2: the edges of their ranges, like of their geographic range.
[34:45] Speaker 2: They're only found within dwellings like human dwellings. Outside maybe
[34:50] Speaker 2: it gets too cold or not great for them, Yeah,
[34:54] Speaker 2: and so they're harder to detect in nature. They also
[34:57] Speaker 2: can live for a surprisingly long time, even though they
[35:00] Speaker 2: are quite fragile, and many throughout their lives will become
[35:03] Speaker 2: injured while capturing prey, so they will lose limbs and
[35:06] Speaker 2: they don't grow back in subsequent molts.
[35:10] Speaker 1: Oh yeah, babies.
[35:12] Speaker 2: There was an experiment that showed that in under house
[35:16] Speaker 2: like environments or conditions with like temperature control and stuff,
[35:21] Speaker 2: male spiders lived on average six hundred and forty six
[35:24] Speaker 2: days and females lived on average seven hundred and ninety four.
[35:28] Speaker 2: So that's like two three years. But twenty five percent
[35:33] Speaker 2: of females lived for more than one thousand days and
[35:36] Speaker 2: the record was one thousand, seven hundred and fifty five.
[35:41] Speaker 2: It's a long time. They are long lived. They are
[35:44] Speaker 2: long lived, very long lived.
[35:45] Speaker 1: But just hanging out in your bookshelf, in.
[35:47] Speaker 2: The book you never reach, it's chilling, yeah, because there.
[35:50] Speaker 2: They also do really well under with very low resources.
[35:55] Speaker 2: So that was with food and water. That's seventeen hundred beyond.
[36:00] Speaker 2: But another experiment found that spiders, these spiders can live
[36:03] Speaker 2: for six months in air tight containers without food, water,
[36:06] Speaker 2: or air.
[36:07] Speaker 1: What So they just like shut down metabolism entirely. I think, so,
[36:13] Speaker 1: just like we will rest, you will really good at that, yep, yep.
[36:18] Speaker 2: But when they do dine, they prefer dead prey over
[36:22] Speaker 2: live prey. And that dead prey could be freshly killed
[36:26] Speaker 2: several months old. Maybe it was killed by insecticides or
[36:29] Speaker 2: another brown recluse. They that's what they like.
[36:32] Speaker 1: Okay, sorry, Then why do they have such intense venom?
[36:37] Speaker 2: I don't know that I really tried to find like
[36:42] Speaker 2: evolutionary blobby blah about venom ecological role for brown recluses specifically,
[36:48] Speaker 2: and maybe my search terms were off. I don't know.
[36:53] Speaker 2: Maybe we are just unlucky that like there's like the
[36:56] Speaker 2: compatibility that venom just happens to be really compatible with
[37:00] Speaker 2: us blood. I don't know, like.
[37:02] Speaker 1: Breaking that's just so interesting if they're mostly eating dead
[37:05] Speaker 1: stuff and they're not aggressive even to other spiders. Yeah,
[37:08] Speaker 1: or is it like because I know and I wish
[37:10] Speaker 1: that I had looked into this more, but I know
[37:12] Speaker 1: there's like you know, the the people who want us
[37:15] Speaker 1: all to be less afraid of spiders will say how
[37:16] Speaker 1: much more potent certain spiders venoms are, but they can't
[37:20] Speaker 1: penetrate our skin right like legs and stuff. And I
[37:24] Speaker 1: don't I've never looked into the veracity of those claims,
[37:26] Speaker 1: but like, maybe that is the case, and so it's
[37:28] Speaker 1: just like combo of bad luck. They've got super sharp little.
[37:32] Speaker 2: I wish I knew more. So interesting, but yeah, they're
[37:35] Speaker 2: very much sit and wait, even if so they'll like
[37:38] Speaker 2: kill something and then weight come back to it later
[37:40] Speaker 2: or whatever. But ninety two percent motionless of their lives
[37:45] Speaker 2: not motionless, motionless, imagine it's quite relatable. Yeah, just like
[37:51] Speaker 2: many days, I feel like ninety two percent. On the
[37:55] Speaker 2: reproductive front, they're not very prolific compared to other spiders,
[37:58] Speaker 2: so their eggsacs can like fifty eggs, about half of
[38:02] Speaker 2: which hatch. But there are other spiders that hundreds to
[38:05] Speaker 2: thousands of eggsack or that of eggs and their eggsacs.
[38:09] Speaker 1: Yeah, yep.
[38:11] Speaker 2: So these spiders, as you can see, have rich lives
[38:14] Speaker 2: beyond their venomous potential. But I will acknowledge that, yes,
[38:18] Speaker 2: their venom is one of the more interesting things about them.
[38:22] Speaker 2: So let's talk about it in a little bit more detail. So, Aaron,
[38:25] Speaker 2: you covered all the ins and outs of this specific
[38:28] Speaker 2: venom of the brown recluse, And so what about spider
[38:31] Speaker 2: venoms more broadly? Again, they are incredibly varied. They all
[38:36] Speaker 2: spiders produce them. Well, sorry, the vast, vast majority of
[38:39] Speaker 2: all spiders produce venom. There are there's one family that
[38:42] Speaker 2: has lost that had once had apparently ability, but they've
[38:47] Speaker 2: lost the ability.
[38:48] Speaker 1: To make fun I'm missting, yep.
[38:51] Speaker 2: And across the over fifty thousand spider species that make venom,
[38:55] Speaker 2: they make a bunch of different kinds. How many we
[38:58] Speaker 2: have no idea because spider VSA is relatively understudied compared
[39:02] Speaker 2: to things like snake venom or even scorpion venom, and
[39:06] Speaker 2: most research looking at spider venom has been directed towards
[39:10] Speaker 2: these handful of species that are medically important. So why
[39:15] Speaker 2: do spiders make venom? Why does anything make venom? It
[39:18] Speaker 2: usually falls into one of three reasons. There's defense, there's competition,
[39:22] Speaker 2: and there's predation. So most spiders make venom to incapacitate
[39:27] Speaker 2: and kill their prey. But defense also, of course plays
[39:29] Speaker 2: a role. So, for instance, some research has found that
[39:33] Speaker 2: in some species, males and females make different kinds of
[39:37] Speaker 2: have different types of venom profiles, with females making more
[39:41] Speaker 2: complex but less toxic venoms. In one situation, this might
[39:46] Speaker 2: be due to how males and females of different species live.
[39:50] Speaker 2: So maybe males of a species are more likely to
[39:52] Speaker 2: encounter a wide range of prey, maybe they have more
[39:56] Speaker 2: generalist venom. For example, maybe females of the species move
[40:01] Speaker 2: around more and carry an eggsack, need to eat more,
[40:04] Speaker 2: so they might have a more powerful venom for defense.
[40:08] Speaker 2: Venom composition can also change from individual to individual and
[40:11] Speaker 2: across the spider's lifespan. Venom is costly to make, so
[40:15] Speaker 2: they're typically going to be very economical with Like, there's
[40:18] Speaker 2: been studies that show that the amount of venom injected
[40:21] Speaker 2: by a spider or deployed by a spider correlates sometimes
[40:25] Speaker 2: to prey size. So if this prey is smaller, they're
[40:30] Speaker 2: going to use less. If the prey is bigger, they're
[40:31] Speaker 2: going to use more.
[40:32] Speaker 1: So they're like really making a decision and controlling those.
[40:36] Speaker 2: Well decision is yeah, okay, they modulate how much venom
[40:40] Speaker 2: is used. How interesting, And they typically will only deploy
[40:44] Speaker 2: it as a last resort, So, especially in a defensive situation,
[40:47] Speaker 2: they're like, can I can I just run away without
[40:51] Speaker 2: wasting all of this venom? Or do I have to
[40:54] Speaker 2: use it? And so that's why like brown recluse, it's
[40:56] Speaker 2: like only in the last resort they're trapped. Oh my god.
[40:59] Speaker 1: Yeah, do we have any evidence do they dry bite
[41:02] Speaker 1: the way that sometimes snakes do?
[41:04] Speaker 2: I think that they do. Yeah, I think that's what
[41:06] Speaker 2: I read. So interesting, But yeah, spiders can inject their
[41:10] Speaker 2: venom with a bite. They can imbue it into their
[41:12] Speaker 2: silk so that if a little critter comes, it can
[41:15] Speaker 2: start acting to either immobilize it or kill it. What
[41:19] Speaker 2: And there's even some spiders that can spray it defensively,
[41:23] Speaker 2: similar to like spitting cobras.
[41:26] Speaker 1: Out of their fangs.
[41:27] Speaker 2: Yes, oh wow, exactly. But however, they deliver the venom,
[41:31] Speaker 2: whether it's specialists or general spiders do it well. They
[41:35] Speaker 2: are some of the most successful and abundant predators on
[41:39] Speaker 2: this planet. Each year, this is if you walk away
[41:43] Speaker 2: with one fun fact, this is okay. Each year, spiders
[41:46] Speaker 2: consume between four hundred and eight hundred million tons of
[41:50] Speaker 2: insects around the globe. Whoa. By comparison, humans consume around
[41:56] Speaker 2: four hundred tons of meat and fish every year. Seriously,
[42:01] Speaker 2: that's what I read.
[42:05] Speaker 1: I am. I am astounded bios numbers.
[42:07] Speaker 2: I know, that's a lot of biomass. That's a lot
[42:10] Speaker 2: of a lot of bio and most of that is
[42:12] Speaker 2: other insects, including those characterized as agricultural pests. A healthy
[42:18] Speaker 2: ecosystem means lots of spiders. They play a big role
[42:22] Speaker 2: in food webs, as both predator and prey food webs.
[42:25] Speaker 2: But exactly, I mean, we use web for so many
[42:29] Speaker 2: different things, I really know, but they and in cultivated
[42:33] Speaker 2: areas like farms and orchards, they are of tremendous importance
[42:37] Speaker 2: in keeping down numbers of critters like aphids or any
[42:42] Speaker 2: other any other like pests. None are coming to mind
[42:45] Speaker 2: right now, but they're especially helpful in areas that are
[42:48] Speaker 2: pesticide free because if you're if you're like, if you
[42:50] Speaker 2: can avoid just like spraying and spraying and spraying, right,
[42:53] Speaker 2: spiders are your friends.
[42:55] Speaker 1: Yeah, they are.
[42:56] Speaker 2: They've also been used in other contexts for biological control pests. So,
[43:00] Speaker 2: for instance, some studies have explored the use of spider
[43:03] Speaker 2: species that prey on brown reclus to keep numbers down
[43:07] Speaker 2: within dwellings. So they're like brown recluse do have natural predators.
[43:12] Speaker 2: If you don't want a house infestation, that's understandable.
[43:15] Speaker 1: They do.
[43:16] Speaker 2: They do pose you a medical risk, and so you could.
[43:21] Speaker 2: So there's been some studies saying, what if we introduce
[43:24] Speaker 2: or have present the other spiders that occur in this
[43:28] Speaker 2: area that prey on brown recluse, it's a great idea.
[43:32] Speaker 2: Another study found that they when they introduce spiders. It's
[43:36] Speaker 2: an old study, but they introduced spiders and houses in
[43:39] Speaker 2: South Africa that preyed on flies. And this is not
[43:41] Speaker 2: brown reckless related, but they found that cases of GI
[43:46] Speaker 2: infections declined with the declining fly population, interesting because as.
[43:51] Speaker 1: They would move around to be gross around.
[43:55] Speaker 2: Yeah, but spiders are on the decline, like in populations
[44:01] Speaker 2: of iraqnids also seemed to be decreasing over the past
[44:04] Speaker 2: decades across the entire globe, and what that will mean
[44:07] Speaker 2: for ecosystems is unclear. Can't be good. One of the
[44:11] Speaker 2: major hurdles though, in conservation of spiders, just like in
[44:15] Speaker 2: conservation of parasites, is the widespread dislike and fear that
[44:19] Speaker 2: surrounds this group of animals. So there's one study that
[44:23] Speaker 2: found that between twenty and thirty percent of people in
[44:26] Speaker 2: the UK felt anxious or fearful around spiders, and an
[44:31] Speaker 2: estimated three to six percent of the global population has
[44:34] Speaker 2: a rachnophobia.
[44:36] Speaker 1: That's actually lower than I expect. Three to six percent.
[44:39] Speaker 2: Well, I think it's to have it be characterized, like
[44:42] Speaker 2: I think, as an actual illness, as an actual illness. Yeah,
[44:45] Speaker 2: it has to reach a certain threshold. There are questionnaires
[44:47] Speaker 2: that try to assess this and like yep, physiological responses.
[44:51] Speaker 2: But I do think that like that twenty thirty percent
[44:54] Speaker 2: of people was specifically in the UK, I think that
[44:56] Speaker 2: that's probably fairly standard, if not like under low, Yeah,
[45:01] Speaker 2: in some areas, higher in others. Yeah, fear of snakes
[45:05] Speaker 2: is up there too, as well as like one of
[45:07] Speaker 2: the other common phobias. But I would guess that more
[45:10] Speaker 2: people know the word a rachnophobia than they do the
[45:14] Speaker 2: phobia for snakes. Do you know the one for snakes?
[45:17] Speaker 1: Nope?
[45:17] Speaker 2: Oh see, I didn't love phobia. No, that's too general,
[45:21] Speaker 2: it's oh video folly, phobia, fideophobia.
[45:24] Speaker 1: Yeah, I didn't know that.
[45:25] Speaker 2: Yeah, me either fear of spider, Like, why do we
[45:29] Speaker 2: fear spiders? Right? And it's been suggested that it is
[45:32] Speaker 2: evolutionarily ingrained within us because the spider bites can be harmful, right,
[45:40] Speaker 2: but the number of spiders that actually pose threat to
[45:42] Speaker 2: humans is pretty low. This is kind of a false equivalency.
[45:46] Speaker 2: But you are twenty five hundred times more likely to
[45:48] Speaker 2: be killed by a human than a spider as an example.
[45:54] Speaker 2: This fear is also heavily tinged with disgust, yeah, which
[45:59] Speaker 2: is is kind of interesting in the context of other
[46:02] Speaker 2: animals that we fear right, Like, I don't think snakes
[46:05] Speaker 2: is highly associated with disgust, right, it's just fear fear, yeah,
[46:09] Speaker 2: And some researchers have suggested that this presence of disgust
[46:13] Speaker 2: points toward it being a learned fear, like carried down
[46:17] Speaker 2: in cultures over the years, and historically in many regions
[46:22] Speaker 2: of the world, spiders were thought to carry disease and
[46:25] Speaker 2: transmit disease. Huh. And so maybe fear and disgusting towards
[46:31] Speaker 2: spiders lingers because we thought that they caused disease disease. Interesting,
[46:37] Speaker 2: It could be both, It could be partially evolutionary evolutionarily
[46:40] Speaker 2: and grained, it could be learned.
[46:44] Speaker 1: I always just thought it was the way that they move.
[46:47] Speaker 1: I was scared, you know, I was very scared of
[46:50] Speaker 1: spiders for most of my entire life and had to
[46:54] Speaker 1: unlearn that fear in Panama, in actually even before Panama,
[46:59] Speaker 1: like in part just doing entomology, having to be able
[47:01] Speaker 1: to hold a tarantula to show to little kids. Yeah,
[47:06] Speaker 1: and then yeah, and then it was just like I
[47:07] Speaker 1: didn't I was embarrassed to be an entomologist in training
[47:12] Speaker 1: and be afraid of spiders. And then having kids, I
[47:16] Speaker 1: was like, I don't want them to be afraid, and
[47:18] Speaker 1: so yeah, so now I like really have to be like,
[47:21] Speaker 1: I'm not afraid at all.
[47:22] Speaker 2: But there is just something linger that.
[47:24] Speaker 1: Lingers where when I like, I will always pick them
[47:27] Speaker 1: up and take them outside. We'll look at them. Oh,
[47:28] Speaker 1: these are so fun and cool, look at their little
[47:30] Speaker 1: body parts. But there's just something inside you're freaking out. Yeah,
[47:35] Speaker 1: hide it very, hide it concealed. Don't feel Yes, I
[47:41] Speaker 1: don't feel.
[47:42] Speaker 2: I liked. I've never had an issue with spiders, cockroaches
[47:45] Speaker 2: and how centipedes have really been my interesting my absolute
[47:50] Speaker 2: terror creep out. Yeah, just vomit, like feeling like nauseous
[47:55] Speaker 2: and cold sweats all over. How interesting apecially, Yeah, but
[47:59] Speaker 2: I mean growing up in we would have the palmetto
[48:01] Speaker 2: bugs and they I was one that like crawled into
[48:05] Speaker 2: my shirt and so like I just I have I
[48:08] Speaker 2: don't like that. Still to this day, Panama was rough
[48:11] Speaker 2: on the cockroach front. I would find them on my toothbrush,
[48:13] Speaker 2: on my pillow, everywhere in my life. On my one
[48:17] Speaker 2: crawled up my naked leg anyway. So, but we all
[48:21] Speaker 2: have spider stories, and it turns out, yeah, and spider's
[48:24] Speaker 2: loom large in many cultures around the world. In Navajo
[48:28] Speaker 2: and Pueblo creation stories, spider woman wove into existence the
[48:32] Speaker 2: world and everything in it, and everything she created remains
[48:36] Speaker 2: connected to her through spider silk, ensuring continued access to
[48:41] Speaker 2: her wisdom and her protection.
[48:43] Speaker 1: That's really nice.
[48:45] Speaker 2: There's the Greek myth of a Rackney, a talented weaver
[48:48] Speaker 2: who was turned into a spider by the envious goddess Minerva.
[48:53] Speaker 2: Mm hmmm mm hmm. She was like, you want to weave,
[48:56] Speaker 2: here you go. You think you're better than me. Ever,
[49:01] Speaker 2: but do spiders show us this? So many different things,
[49:04] Speaker 2: like there's no one word or personality trait that we
[49:09] Speaker 2: ascribe to spiders continuously, right, Like sloths are lazy, foxes
[49:15] Speaker 2: are sly. Spiders are everything. They're there. This is interaction,
[49:21] Speaker 2: this intersection between horror and beauty. They're solitary, they're treacherous,
[49:27] Speaker 2: so many different things. She lob in Lord of the Rings,
[49:32] Speaker 2: it in Stephen King's It is a spider. Oh. They're
[49:36] Speaker 2: also women like yeah, often they are feminine. They are
[49:41] Speaker 2: evoked in stories of fatales. These treacherous and deceitful women
[49:45] Speaker 2: who lay their spiders are also recognized for their creative
[49:50] Speaker 2: talent and their hard working nature. They've given us phrases
[49:53] Speaker 2: like web and network, spinning a tail, and spiders teach
[49:58] Speaker 2: us resilience, like in the nursery rhyme of the Itsy
[50:01] Speaker 2: bitsy spider then crawled up the spout again, and then
[50:05] Speaker 2: every single time, every single time. You just got to
[50:08] Speaker 2: keep doing it. Ebie White, the author of Charlotte's Web,
[50:12] Speaker 2: wrote quote, once you begin watching spiders, you haven't time
[50:16] Speaker 2: for much else. The world is really loaded with them,
[50:19] Speaker 2: Isn't that cute? The story of how he got the
[50:23] Speaker 2: idea for spider for Spider's Web for Charlotte's Web is
[50:27] Speaker 2: he had a like, found a spider in a barn,
[50:31] Speaker 2: brought her in a shoe box to his apartment in
[50:34] Speaker 2: New York. She hatched a ton of spiders and he
[50:37] Speaker 2: just let them like chill, and he was just like
[50:39] Speaker 2: wanted to see them, and he was enthralled and entranced
[50:42] Speaker 2: little spiders. Yeah, and even I think Darwin at one
[50:46] Speaker 2: point on the voyage of the Beagle, became infatuated with spiders.
[50:50] Speaker 2: He said something like, I am red hot with spiders.
[50:55] Speaker 2: He was like just loved watching them and loved watching
[50:58] Speaker 2: them balloon across the the ship. But it is kind
[51:02] Speaker 2: of cool. It's true the world is loaded with spiders.
[51:06] Speaker 2: And I used to do this a lot, especially in Panama.
[51:09] Speaker 2: But I highly recommend next time you're somewhere in nature
[51:13] Speaker 2: at night, could even just be a backyard, take out
[51:16] Speaker 2: a flashlight, headlamp, shine it on the ground. Those glittering
[51:20] Speaker 2: sparkles that you see scattered throughout the grass, throughout the trees,
[51:24] Speaker 2: throughout the bushes, many of those are spider eyes. Yea.
[51:28] Speaker 2: And it kind of is like, maybe that's scary at first,
[51:32] Speaker 2: and maybe it's comforting because how often do you actually
[51:35] Speaker 2: see them. How often do you interact with them? These
[51:38] Speaker 2: things are doing so much work for us. We don't
[51:40] Speaker 2: have to roll out the welcome mats for the brown
[51:43] Speaker 2: reck close to black widows of the world.
[51:45] Speaker 1: Take them out of your house if you don't want
[51:47] Speaker 1: them inside.
[51:48] Speaker 2: Yes, doing this episode, I think I've never had an
[51:51] Speaker 2: issue with spiders, but it did make me kind of
[51:53] Speaker 2: take a step back and go, oh, there is a
[51:55] Speaker 2: lot of work that these spiders do for us, and
[51:58] Speaker 2: they are cute and they are one and so that's
[52:02] Speaker 2: all I've got about brown reckless bites do we have
[52:06] Speaker 2: and spiders in general? I don't know what I'm gonna
[52:08] Speaker 2: do for other Spider Venom episodes.
[52:09] Speaker 1: Hey, we'll have more, don't you worry.
[52:11] Speaker 2: We'll figure it out. But do you have any for
[52:13] Speaker 2: me about the.
[52:16] Speaker 1: No Eric? I think what's interesting is that, unlike almost
[52:44] Speaker 1: every other disease we've ever covered, we probably overestimate rather
[52:52] Speaker 1: than underestimate how often we're bit by spiders in General's so.
[52:55] Speaker 2: Funny, right first, is that the first time I can't.
[52:58] Speaker 1: Remember another time that we maybe someone who knows our
[53:02] Speaker 1: podcast better than we do.
[53:04] Speaker 2: Can tell us.
[53:06] Speaker 1: But especially when it comes to spiders like brown recluses,
[53:09] Speaker 1: like most of the time, if you think it is that,
[53:12] Speaker 1: it probably isn't, which is so interesting. There was a
[53:16] Speaker 1: paper from two thousand and six that went through all
[53:20] Speaker 1: of the case reports that they could find of supposed
[53:23] Speaker 1: brown recluse bites in the US, and of nine hundred
[53:26] Speaker 1: and eight case reports, only eight percent of those were
[53:30] Speaker 1: actually confirmed with a spider and confirmation that that spider
[53:34] Speaker 1: was a brown recluse. So it's really hard to say
[53:38] Speaker 1: how often people are actually being bitten and how often
[53:41] Speaker 1: those bites are bad enough to really need medical care well.
[53:45] Speaker 2: And it's also interesting it's probably both underdiagnosed and overdiagnosed
[53:48] Speaker 2: because how many people get bitten and never realize it.
[53:51] Speaker 1: Never even realize it exactly. Although there was that paper
[53:55] Speaker 1: that you said where they found two thousand spiders over
[53:57] Speaker 1: the course of six months in a house, no.
[53:59] Speaker 2: One was No one was ever bigg Yes, I forgot
[54:02] Speaker 2: to mention that that is a pretty cool.
[54:04] Speaker 1: Two thousand spiders all around your house. Although that was
[54:07] Speaker 1: a big house, you said, twenty nine, twenty undreds big.
[54:10] Speaker 2: It's a big house, big house. It is reassuring, though,
[54:13] Speaker 2: it is very.
[54:13] Speaker 1: Reassuring, right, they're just living among thousands of brown recluses
[54:17] Speaker 1: and never having any issues with it. That being said,
[54:21] Speaker 1: I read that in Brazil, where there's a different species
[54:24] Speaker 1: of los Oficell's, that's most important. There there's about three
[54:27] Speaker 1: thousand annual reports of los Ofcell's bites. Are those all
[54:32] Speaker 1: for sure confirmed? I don't know. That's the data that
[54:36] Speaker 1: I have, And like you said, it is not unlikely
[54:40] Speaker 1: that the distribution of these spiders could change due to
[54:44] Speaker 1: future climate scenarios, not necessarily expand, but who knows. It
[54:50] Speaker 1: just makes it more important that people who work in
[54:53] Speaker 1: the medical profession know where these spiders live, if they
[54:58] Speaker 1: live near you, or have somebody on staff who's able
[55:02] Speaker 1: to help identify spider race, which I think we don't
[55:04] Speaker 1: have enough of. So here's shout out to your local
[55:07] Speaker 1: rachnologist or entomologist.
[55:09] Speaker 2: Does poison control do spider bites?
[55:13] Speaker 1: I imagine that they, but like they're not. You're not
[55:16] Speaker 1: going to be able to like send them your specimens necessarily, Yeah,
[55:21] Speaker 1: as far as I know, so take a picture, but
[55:24] Speaker 1: I don't. I don't know. It's it's a great question,
[55:29] Speaker 1: but that's that's all I have. Aaron for brown recluses.
[55:32] Speaker 2: Brown reckluses. Hopefully we did a little bit of yeah,
[55:36] Speaker 2: pr uplift of the spars.
[55:39] Speaker 1: Don't seek them out, just leave them be.
[55:43] Speaker 2: And that's that's yes, it should we tell the people
[55:49] Speaker 2: where to learn more about me? Definitely, Okay. I have
[55:52] Speaker 2: a bunch of different kind of an assorted collection of
[55:54] Speaker 2: papers by Sandage at All from twenty two thousand and five,
[55:58] Speaker 2: Brown Recluse Spiders over View of Biology, life history and
[56:01] Speaker 2: pest Management was an interesting one. Just an overview of
[56:05] Speaker 2: them by Lytica from twenty twenty two, The Biology and
[56:09] Speaker 2: Evolution of Spider Venoms if you want to know more
[56:11] Speaker 2: about venoms broadly, and then by Davy from nineteen ninety four,
[56:17] Speaker 2: The Disgusting Spider, The Role of disease and illness and
[56:21] Speaker 2: the Perpetuation of Fear of Spiders.
[56:23] Speaker 1: Oh, I love that. I also loved that Biology and
[56:26] Speaker 1: Evolution of Spider Venoms paper. That was my first one
[56:28] Speaker 1: on my list. There's also a chapter in the Handbook
[56:31] Speaker 1: of Clinical Toxicology of Animal Venoms and Poisons from twenty
[56:35] Speaker 1: seventeen that was on the biology and distribution of spiders
[56:37] Speaker 1: and medical importance. There's also a paper that was really interesting,
[56:41] Speaker 1: super recent twenty twenty six in the Journal of Medical Entomology.
[56:44] Speaker 1: That was Recluse spiders Contesting myths on distribution, bye behavior
[56:48] Speaker 1: and medical risk in Florida.
[56:49] Speaker 2: I saw that one. Yea so interesting.
[56:51] Speaker 1: They only have invasive Mediterranean recluse species in Florida and
[56:55] Speaker 1: even those are very low abundance. And they did super
[56:58] Speaker 1: interesting like trying to force these things to bite and.
[57:01] Speaker 2: They just didn't, right, they just wouldn't. They're like, I
[57:04] Speaker 2: don't why this meeting costs me tonight?
[57:08] Speaker 1: Want to keep it?
[57:09] Speaker 2: Yeah?
[57:09] Speaker 1: Anyways, that was great. There was a New England Journal
[57:11] Speaker 1: Medicine paper from two thousand and five, Bites of brown
[57:13] Speaker 1: recluse spiders and Suspected necrotic Arachnittism.
[57:16] Speaker 2: Listen.
[57:17] Speaker 1: There's so many more. Check them out on our website
[57:20] Speaker 1: This podcast will Kill You dot com under the episodes
[57:22] Speaker 1: Tap Yes.
[57:23] Speaker 2: Thank you to Bloodmobile for providing the music for this
[57:25] Speaker 2: episode and all of our episodes.
[57:27] Speaker 1: Thank you so much. Thank you to Leanna and Tom
[57:31] Speaker 1: and Mark and Pete and everyone at Exactly Right for
[57:34] Speaker 1: everything that you do to make this podcast and our
[57:37] Speaker 1: YouTube Hello Possible.
[57:39] Speaker 2: Yes, thank you, thank you, and thank you to listeners
[57:42] Speaker 2: for listening. Watchers for watching whatever, people who do stuff
[57:46] Speaker 2: with this podcast. I need to find a better way
[57:48] Speaker 2: to say this. Thank you. We do this for you
[57:51] Speaker 2: and we hope you like it and it means everything
[57:54] Speaker 2: it does.
[57:55] Speaker 1: We will do more spiders by the way, so tell
[57:57] Speaker 1: us the spiders that you want to hear next. And
[58:01] Speaker 1: a special shout out to our patrons, thank you so
[58:03] Speaker 1: much for your support over on Patreon. It really does
[58:05] Speaker 1: mean more than we have good words to tell you truth.
[58:09] Speaker 2: Until next time, wash your hands you filed the Animals

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