Not the prettiest jumping spider I’ve seen

I’m used to seeing spectacularly pretty Australasian jumping spiders, and this one, the genus Simaetha, isn’t exactly dazzling.

Australian representatives of the two extant Simaethina genera: A, C, E, Simaetha sp. (female); B, D, F, Simaethula sp. (female). Specimens are shown in dorsal view (A, B), lateral view (C, D) and frontal view (E, F). Scale bars: 0.5 mm (B, D, F), 1 mm (A, C, E).

This one, though, has the excuse that it’s between 11 and 16 million years old. It isn’t that old — I’d expect that the planet had lot of jumping spiders during the miocene — but it’s nice to seen an example from that period.

Simaetha sp. indet. (AM F.161027). Only known specimen: A, light microphotograph. B, scanning electron micrograph. C, morphological interpretation of light and electron micrographs. Abbreviations: LL, left leg; RR, right leg; AME, anterior median eye; PME, posterior median eye. Scale bars: 0.5 mm.

It’s also impressive that they could sort out what was what in the squashed bits of that fossil.

On the 8th of October…

…one should spend some time with one’s spiders. I know it is numerically the 10th month, but it should be the 8th month by name, if not for some silly Romans who tried to squeeze a couple more emperors into the calendar. It was feeding day anyway, so I spent a little time giving them treats in celebration.

Here’s Blue, who gobbled down her mealworm instantly, and is now dabbling her toes in her water dish.

It’s getting more difficult to photograph Blue, because she’s covering everything with silk — when you look in from the side, it’s a haze of strands everywhere, and I have to remove the lid to the terrarium to lean in and see what she’s up to.

I fed the Steatoda borealis, the Parasteatoda tepidariorum, and the Latrodectus mactans juveniles as well. I’ve isolated about 80 black widow juveniles in individual vials, and am running out of room in the incubator, so there’s about 80-100 more left in a container together, like a giant colony of black widows. It’s a Darwinian world in there — I figure I’ll let the numbers decline and then extract the biggest survivors.

One thing I’ve noticed is that the isolated individuals, in spite of getting a bounty of fruit flies twice a week, are growing more slowly than some of the black widows in the communal container. Most are small, but there’s a few that stand out as growing distinctly larger than their siblings.


(Photos were taken immediately after I dumped a lot of fruit flies into the container, so they’ve all got their faces snout deep in dinner.)

I have to speculate that maybe, just maybe, some of the spiders are eating their siblings.

Spider gynandromorph!

Arachnologists poking around in Thailand discovered a new species of mygalomorph, Damarchus inazuma. One individual was particularly unusual: it’s a gynandromorph!

Damarchus inazuma sp. nov. gynandromorph (ARA–2021–273). A dorsal habitus (live); B dorsal habitus (preserved); C ventral habitus (preserved). Scale bars: 1 cm (A, B, C).

Female side is on the left, male on the right.

Kunsete, C., Thanoosing, C., Sivayyapram, V., Traiyasut, P. & Warrit, N. (2025) New insights into Damarchus: a new species and gynandromorph description from Thailand (Araneae: Bemmeridae). Zootaxa, 5696 (3), 409–424. https://doi.org/10.11646/zootaxa.5696.3.6

I tried sorting out spiders. They were not cooperative.

This afternoon, I tried to sort out the newly emerged Bold Jumper spiderlings, with limited success. Unfortunately, they were faster and more eager to flee than I expected. I got most of them, but a few are now living in my house.

(The video will premiere tomorrow at 4pm, so you’ll have to wait to see it. Or if you’re a Patreon subscriber you can see it now.)

I didn’t even know she was pregnant

It’s Friday, feeding day in the lab, and I went in this morning to throw wingless flies and mealworms at the horde, all the Steatoda borealis and Latrodectus mactans. I also have one adorable little Bold Jumper, Phidippus audax, that I keep around not because I have experiments in mind, but because she’s cute. Jumping spiders are always adorable. Of course I have to feed her, too.

I tossed in a mealworm, which she instantly devoured, when I noticed…hey, what are all these little dark dots all over the place? She had a silky refuge that she often disappeared into, and now I know that she was nurturing an egg sac. I hadn’t seen it, but apparently it popped in the last day or two.

Here’s a baby Bold Jumper.

Suddenly, I have lots. I put a whole lot of fruit flies into the container to keep them entertained for now…later I’ll have to separate them out into vials.

I ventured into the jungle…I mean, garden

I was feeling a bit robust this morning, and managed to hobble all the way out to the backyard, where I could explore the fauna thriving there. Mary was hovering at my elbow to make sure I didn’t topple over, but I did OK — another week or two, and I might be going on real walks (as long as I don’t do anything stupid.) Things I saw that made me happy:

We spotted two monarch butterflies flitting over the garden. No photos, though, they didn’t land and pose for me.

The place is hopping with grasshoppers, which, while not normally associated with good gardens, is fine with me — the purpose of the garden is making spider food, not tomatoes. Mary may disagree with me.

Oh, and it was so bright. I’m not used to that anymore.

We also had lots of interesting pollinators, like this two-spotted longhorn bee.

Of course, the queen of the garden, the devourer of grasshoppers, the true monarch, was Argiope trifasciata.

It’s a fine crop, and congratulations to Mary on her superlative gardening skills. Maybe tomorrow I’ll make it to the front yard to see what wonders flourish there.

Baby black widows!

Finally, the black widow egg sacs have released their hordes!

Here’s a close-up of one of the spiderlings. Black widows start off with more spectacular patterns — as they mature, they’ll get red and yellow bands and racing stripes, before turning solid black with a blotch of red on the abdomen.

Pretty!