Dicyrtoma dorsosignata

Dicyrtoma dorsosignata

Dicyrtoma dorsosignata is a globular springtail in the Dicyrtoma genus.

Dicyrtoma dorsosignata, Heesch, Netherlands Update: Matty Berg has confirmed this is indeed a new species report for the Netherlands. We're discussing if specimen collection is possible, and possibly the find may be included in a new article.

Update 2: Specimen collected and confirmed successfully:
https://www.jungledragon.com/image/105252/dicyrtoma_dorsosignata_specimen_netherlands.html
Two weeks ago, I photographed my first springtail:

https://www.jungledragon.com/image/104612/dicyrtomina_ornata_heesch_netherlands.html

...which I found on the water surface of a mini-pond in our back yard. A few days ago, I checked it again, and this time found 10 individuals. I first speculated perhaps wind got them into the pond, but now think they walk or fall into it from the edge, with no way to crawl out of it again. This morning I added some branches and leafs so that they do not get permanently trapped.

As before, I collected them into a petri dish for inside photography.

To my joy, the 10 individuals showed some diversity in appearance and size: probably multiple species as well as singular species at multiple instars. To solve the puzzle of which individual is which species, I contacted Frans Janssens, the man behind http://collembola.org/. This seems to be the ultimate in-depth springtail taxonomy reference that Frans has been working on longer than I exist, since 1976.

I'll be sharing a series of photos from this session over the coming days, yet this particular one has some priority. It is speculated to be Dicyrtoma dorsosignata. According to Frans, this is intriguing as it is known thus far as a mediterranean species, typically reported from France, Portugal, Malta, etc. Now that it is online, we hope Matty Berg (the authority on this group in the Netherlands) will confirm it as a possible new species for the Netherlands.

I'll conclude with some "making of" notes, for the interested. From the earlier session 2 weeks ago I learned that handheld 5:1 photography is extremely difficult, as is obvious. So for this 2nd session I experimented a bit with a proper support system:
https://ibb.co/YNg8RXN

The metal frame in the bottom is not a tripod, it's a light stand, the Manfrotto 003. You can't adjust the height of it, it's just a super solid stand. Very heavy, and stays in place. It's shockingly inexpensive given the material and quality. Normally, you'd put an extension pole into the stand, and then add lights or light shapers (umbrellas) to it.

Not this time. I added the spigot (the golden-colored connector, Manfrotto 013) after which you can put anything to it that accepts a standard thread size. In this case, I added a super heavy duty tripod head, the Manfrotto MHXPRO-BHQ2. I normally avoid recommending gear in this place, but gladly make an exception for this jewel. This ballhead tripod head allows for a massive 10kg of load. And it takes it effortlessly. Even when under heavy load, you have fine grained control over movement and friction, in any direction. The ball is fully enclosed and therefore there is no grease. Given the class it competes in, this product is inexpensive and an absolute top performer.

With this support system in place, most of my own movement is negated. Not to mention that it takes a lot of weight out of my hands, making possible a longer session. Focusing at the proper depth still is a challenge. My main method here is to use focus peaking via the live view screen. This paints a red overlay at the area in focus. Yet is tiny in this situation. I've learned that the beginning of their antennae is the proper focal point. Combined with f/8, there's a reasonable chance the head is in focus. Still about only 1 in 8 shots are passable this way, so the strategy is to just shoot lots and hope for the best.

The last challenge is light. With the end of the lens almost hitting the water, it's tricky to light the front of the animal. In this case I used the Godox AK-R11 Dome and positioned it to the side of the petri dish. I don't even own a Godox flash, this is just a cheap yet useful accessory. Next, I place a very strong flash unit in front of it. This effectively floods the scene with light that is strong yet spread. At 5:1 combined with f/8, the effective aperture is f/48. This means the Speedlight needs to fire at full power. Since no speedlight can sustain that for any length of time, I used a flash power pack.

For now I have tentatively identified it as Dicyrtoma dorsosignata. I will update this post once experts have confirmed/rejected this proposal. Dicyrtoma dorsosignata,Europe,Extreme Macro,Fall,Geotagged,Netherlands,Springtail,World

Naming

Stach, 1924.

References:

Some text fragments are auto parsed from Wikipedia.

https://fr.wikipedia.org/wiki/Dicyrtoma

Taxonomy
Kingdom	Animalia
Division	Arthropoda
Class	Entognatha
Order	Symphypleona
Family	Dicyrtomidae
Genus	Dicyrtoma
Species	Dicyrtoma dorsosignata

Photographed in
Netherlands