#jumping spiders

[artifacts-and-arthropods]

Brenthia Moths: these moths can mimic the appearance and mannerisms of a jumping spider so convincingly that actual jumping spiders will sometimes attempt to court them

The markings, posture, and movements of a Brenthia moth (genus Brenthia, also known as a metalmark moth) all contribute to its disguise; the moths move around in short, jerky motions that mimic the movements of a jumping spider, and their hindwings are covered in black-and-white bands that strongly resemble the tucked-in legs of a salticiid spider, especially when the moth displays its unique wing position. The disguise serves as a defensive strategy, enabling the moth to avoid being preyed upon by actual jumping spiders.

In some cases, that disguise may work a little too well, as jumping spiders may actually mistake the moth for a potential mate and then attempt to engage it in a courtship/mating dance (which must be a pretty awkward and bizarre experience for the moth, tbh).

The resemblance between a Brenthia moth and a jumping spider may not seem terribly convincing to us, as human beings, but as this article explains:

When discussing animals mimicking their predator, it is important to remember that we humans are not the target audience. This means that the imitator may not look too convincing in its mimicry to us, but still manages to trigger a desired response from said predator.

Jumping spiders have also been known to respond to Brenthia moths by exhibiting a territorial display, which is yet another behavior that the spiders generally reserve for other spiders.

This study expands on the adaptive benefits of the moth's disguise:

In controlled trials, Brenthia had higher survival rates than other similarly sized moths in the presence of jumping spiders and jumping spiders responded to Brenthia with territorial displays, indicating that Brenthia were sometimes mistaken for jumping spiders, and not recognized as prey.

The illustration below shows the basic/general resemblance between a Brenthia moth and a jumping spider:

Sources & More Info:

New Scientist: Moth's Disguise is so Good, Spiders Love it Instead of Eating it

Animal Behaviour: Sheep in Wolf's Clothing

Science: This Moth Could Pass for a Spider

PLOS ONE Journal: Metalmark Moths Mimic their Jumping Spider Predators

Gil Wizen: Jumping Spider Mimicry in Brenthia Moths

Moths of North Carolina: Brenthia pavonacella

[ratbugs]

it is once again

little guy time

[gardeneticist]

I think one of my favourite jumping spiders is Opisthoncus necator just because its common name is just “The Murderer” for some reason, so if I ever go to look at it on iNat, I am greeted with this very accusatory title and what is essentially its mug shot

[jigglypuffstoz]

well maybe if you looked at some jumping spiders wearing water droplets as hats you’d calm down

[kedreeva]

Willow having a little sippy from water I put down for her.

Willow's breeder caught up with me at the last expo and asked if I still had her. She was surprised when I said yes, and that she's doing just fine. She came to me in May of 2023 as an i8, which means she hatched in fall of 2022. They normally live about 3 years total, so she's definitely getting up there now. Apparently most of the others from her clutch have passed, and the breeder was having multiple people report deaths after owning their spiders for just a short while. She was very frustrated about it and asking about what I'm doing for care.

The thing is, I don't do anything special. Willow has a little bioactive setup with a plant and some springtails. She lives on the window sill of my south-facing window over my kitchen sink, and gets a spritz of water when I do dishes, which isn't every day. She suns herself on the ledge of her mailbox daily, and comes down to the side when she wants to visit or eat. The window is cold in the winter- most care sheets describe a need to keep them at 80F their entire lives but I just don't believe that does anything but shorten their lifespans. Florida is warm, sure, but it's not like it never gets cold. A slight brumation or slowdown of metabolism over cold months is very likely to help them extend their lifespan.

And she's still here, right? She's still here when the rest of her 80F siblings are gone.

Anyway, here's to another year with my little fuzzy friend. To Willow

[ljsbugblog]

we finally found another Myrmarachne ant mimic, in our bathroom of all places.

I've been itching to get some more photos of these spiders since getting my speedlite, but they're very elusive and almost constantly in motion. thankfully this lady was content to explore a sheet of cardboard while I took a million photos of her like a madman.

special shoutout to my wonderful partner for a) spotting the spider in our house and b) wiggling their fingers in front of her to keep her attention while I got these photos (it seems jumping spiders are the wayward cats of the arthropod world lol).

I'll link my other Myrmarachne post here, as its interesting to compare the colouration of the two individuals. likely the same species, but my previous sighting had a much brighter gold on her abdomen.

Red-headed Ant-mimic Spider, female (Myrmarachne erythrocephala).

[celestialmacros]

Been holding out for better IDs from iNaturalist for the jumping spider photos I took in Costa Rica, but I guess it's not gonna happen anytime soon. I can't let this beauty sit in my files any longer

Genus Frigga

November 6, 2024

Playa Conchal, Guanacaste Province, Costa Rica

[luxiiien]

Had the pleasure to bump into this wonderful creature ✨️

[platycryptus]

Two male Platycryptus undatus I saw having a territorial dance-off

I think the one on the right might’ve backed down because he’s holding prey and would rather enjoy his meal in peace

(Massachusetts, 8/5/24)

[memories-of-ancients]

One of this year's Olympic long jump competitors from the country of Arachnistan.

[razehider]

upon finding an Evarcha jucunda that didn't seem particularly shy, i chased her along a wall for a bit in an attempt to get a frontal shot. she was still not very fond of my presence, but the only thing more powerful than a jumper's cowardice is their curiosity, so i got a couple of reluctant glances

she lost interest very quickly, but the difference in color on the AMEs in these last two pics compared to the first two is a nice example of retinal movement. "i pretend i do not see it" type shit

(October 13th, 2024)

[great-and-small]

Opinions on jumping spiders?

Perhaps the MOST charming family of spiders in the world? I love em!

I distinctly remember getting a lot more into the identification of invertebrates when a white-jawed jumping spider happened to scurry across a book I was reading while sitting outdoors. It was an unfamiliar face to me, but I got a positive ID from the iNaturalist app. Since then, I’ve made a significant effort to post bugs I don’t recognize whenever I can. Doing this has literally changed my entire worldview! How lovely to get to know my neighbors better while also contributing to citizen science.

[uncharismatic-fauna]

Uncharismatic Fact of the Day

Orsima ichneumon is a master of optical illiusions: look at it one way, it's an ant; look at it another way, it's a spider! This species has likely evolved its unique appearance as a way to deter predators, as many ants-- especially brightly colored ants-- can be highly toxic.

(Image: Orsima ichneumon, whose head is on the left, by Caleb Nicholson)

[rattyexplores]

S. violacea, a very round species of jumping spider.

14/01/24 - Simaethula violacea

QLD:WET

[kedreeva]

Willow, asking for Uppies!

[video id: a female regal jumping spider with pink chelicerae is standing on a hand tapping her front legs on the person's skin and then raising them up while also looking up. She puts them down and then looks around, then walks down the person's arm closer to them and turns to raise her arms again like a small child asking to be picked up.

End ID]

[ljsbugblog]

exciting find today!! I believe this is a Red-and-Black Ant Mimic, a species of jumping spider evolved to mimic Strobe ants (family Opisthopsis). While I dont have a positive ID, this female looks like she's mimicking the Black-Headed Strobe Ant (Opisthopsis rufithorax).

Ant mimic spiders (Salticids or otherwise) are so fascinating to me, but I rarely get to see them, let alone get a clear photo. This girl was moving around so quickly (also mimicking the quick, jagged movements of Strobe ants) and I didn't have my macro on me, so sorry for the photo quality! she's too cool not to share anyway imo :,)

🕷!!!

Red-and-Black Ant Mimic, female (Myrmarachne bicolor).