Isotomurus only has the macrosetae on the last 3 abdominal segments.

In terms of species, I’d guess that this is Isotoma anglicana given the colour, but I’d need a microscope to be totally sure!

It looks close to Vertagopus, but a subtle detail is that Vertagopus only has a coat of quite short hairs (although it’s a dense coat). Here there are some much longer hairs (macrosetae), and it looks like they’re on all abdominal segments, indicating Isotoma.

Thank you to @nmaybury4.bsky.social for support during the sampling and for accurately translating the original Latin description, and to @jstgerlach.bsky.social for permission to study @peterhousecam.bsky.social's springtail fauna!

I do think you are right with Proisotoma minuta!

Sorry for the delayed response! The mucro does look sufficiently narrow (and the anal spines sufficiently small) for me to be happy for this to be Hypogastrura manubrialis!

Congratulations! 🥳

A photo from the side would help if possible!

Regarding the mouthparts, my technique is usually to clear the specimen using NaOH or KOH, and then squash under a coverslip. Usually then, if the specimen is cleared well enough, you can see the mouthparts through the head without any fiddly work!

You're certainly right that this is in the Hypogastrura/Ceratophysella group! With small anal spines it'll be Hypogastrura, but I'm not 100% confident that the shape of the mucro is definitely manubrialis - it can be hard to judge depending on angle, but in photo 4 it looks a little broader

(S. trinotatus has these setae, while bimaculatus does not)

Finding hyper-specific details like this to back up an identification never fails to make me smile!

I will finish by sharing this beautiful and romantic video of Sminthurides courtship. One of my favourite things!

www.youtube.com/watch?v=p7IV...

🧵7/7

Finally, this is the tiny Sminthurides bifidus. These are synanthropic aquatic springtails found on the edge of glasshouse water features and fish tanks. The dorsal black marking is quite variable.

The males are smaller and have antennal clasping organs to grasp the females in courtship! 🧵6/7

This is Seira domestica, a slender springtail almost never found outdoors (in the UK, at least). Lepidocyrtus have similar iridescent scales but have 2 teeth on the mucro (furca apex), not 1.

When assembled, this will be the first reference-quality genome from the subfamily Seirinae! 🧵5/7

This is Sminthurinus igniceps, a relative but less distinctive. It can be told from dark S. aureus by having a head paler than the body, and from S. domesticus by having mostly orangey antennae.

This species is also synanthropic, but seemingly moving out more into the wider countryside. 🧵4/7

Despite its spots which seem to glow among the woodchips, S. bimaculatus is very similar to S. trinotatus. You need to look for a pair of hairs called subapical ventral setae on the dens, part of the springing organ (furca) that gives springtails their name. This arrow shows where they'd be! 🧵3/7

This beautiful species, Sminthurinus bimaculatus, has been the British springtail I've most wanted to see. As with the other 3 spp., it's primarily synanthropic, meaning it's associated with human habitats like this flowerpot. 🧵2/7

Yes, sorry for the delay!

While the data are thin for signata and flavosignata, it’s the case that minuta, saundersi & ornata can be found under the same log. Despite apparent morphological identicalness, there could be other reasons they don’t outcompete each other, e.g. physiological/metabolic adaptations to different food

That's exciting! I'm on the look out for springtail samples from across the world for a future project - I'll direct message you!