Springtails, Spinothecinae and neck organs

A few years ago, after having spent years watching and photographing countless globular springtails in the UK, I'd become aware of a highly unusual family of Collembola after reading Steve Hopkins' book, 'Biology of the Springtails'. The family was limited to a few genera and species in a few countries in the southern hemisphere.
Unlike every other globular springtail, the Spinothecinae uniquely had two tubular neck organs, probably for oxygen transfer, though no-one really knew for sure.  I was especially intrigued by the Australian Adelphoderia regina, as it had a huge, strongly defined pair of neck organs, and four ocelli in each eye patch, very different to the other members of the family., with thin tubular organs and three ocelli.  
I found the 1982 paper online, authored by Dr. Penny Greenslade, describing the as then new genus, as well as a revision of the entire family. Excitingly for me, it described how the Tasmanian animal was bigger and strongly coloured than the mainland specimens. That decided it. I would try and find it in Tasmania.

Within a few days of arriving, beneath the tree ferns at St Columba Falls in the east of Tasmania, I'd found and photographed my first Adelphoderia regina, a juvenile, complete with those bizarre neck organs. They were unmistakable. I also saw my first Acanthanura, the genus of famous Australian 'giant' springtails and got a leech in my eye. That was a great day.

Adelphoderia regina, St. Columba Falls, Tasmania

Watching its slow movements put me in mind of the Arrhopalites species I liked so much from the UK. And I wasn't far off the mark. The Arrhopalitidae are closely related. 
 But it wasn't until I found it again Tasmania's Southern Forests that I really saw how colourful and big the adults could be.

A. regina, found near Geeveston, Tasmania

The day after finding A. regina, I was out in the bush down a forestry track as the trucks kicked up dust into the heat, carting away another giant tree, destined for chipping, with that famous Tasmanian disregard for their amazing rainforests. Under some deeply buried stones I found another Adelphoderia species, this time without pigment. After some research I found that it had been recorded in Australia as a cave species before, but still waited to be described. And it still waits, along with another eyeless species existing in a cave somewhere in the north of Tasmania, as well as a possible two or three more species in Tasmania and on the mainland. 

Adelphoderia species, Tasmania.

After the excitement of seeing the Adelphoderia species, it was a little disappointing not to have found Spinotheca in New Zealand, as I had been there for a month before heading for Tasmania. But after going back over all the photos I had taken in Tairua, NZ, I found that I had already taken some bad pictures of Spinotheca magnasetacea. An adult is only 0.6mm, which was why I hadn't noticed the small neck organ in the photos before.

Spinotheca magnasetacea, Tairua, NZ Feb 2014

So when I returned to New Zealand after a month of Tasmania, I decided to try and take better photos of the species and once again, just for fun, try and find Adelphoderia there too, despite the fact that according to the description, the genus was endemic and limited to Tasmania and the southern parts of mainland Australia.
And, crazily enough, I did find it, in the first week of being back on South Island. A brickish-coloured adult and a juvenile in a cave, as I balanced on a wet rock above a river, with my camera in the dark. I failed to get a specimen though, which was frustrating.

Adelphoderia species, from a cave near Nelson, NZ

I then amazingly managed to find and photograph yet another Adelphoderia species a few weeks later, looking very purple, and very much like A. regina from Tasmania. By this point, I was in Punakaiki on the west coast of South Island. Just one animal, wandering slowly on some fallen bark amongst a multitude of S. magnasetacea.

I also failed to get that specimen, though I did get better shots of S. magnasetacea. 

And soon after, a cave Spinotheca species, again, as yet unrecorded or described. I never took specimens there either.

Close up of Spinotheca species' thin, tube-like neck organ

When I returned back to Australia, it was partly to meet up with the author of the Spinothecinae paper I'd read the year before: Dr. Penny Greenslade, a force of nature, irascible and glorious. We became friends over the next year, both linked by an unstoppable love for Collembola. During one of our conversations, the possibility of Adelphoderia existing in New Zealand was summarily dismissed, despite my insistent complaining. Even with photos, without specimens it was just a Spinotheca species, not Penny's beloved Australian A. regina. 

So after returning back to the UK, and more travelling, I arrived back in New Zealand the next year, determined to collect my Adelphoderia specimens and prove to Penny that I was right...
Once again, I found a juvenile, this time on North Island, in some regenerating bush in Thames.


This time, I got a specimen, but my tube leaked, the specimen dried out and it was lost.
It was beginning to feel impossible.

I finally returned to Punakaiki and walked the six kilometres into the bush to the spot that I'd discovered them before. And there under a rotting log was a big adult specimen and a juvenile which I at last succeeded in collecting.

When I met up with Penny again, I presented the tube of Adelphoderia specimens to Penny with great glee. Probably too much. After she had cleared the specimens, she told me that the animals had dissolved, so as far as she was concerned, Adelphoderia was still an endemic Australian genus. She let me suffer for a few extra minutes before relenting and agreeing that I was right. Officially, the genus was in New Zealand too. Ha.

Often, it's the smallest things that make you the happiest.