Temnothorax saxonicus

It's been too long since I last added anything to this blog, so it is a shame that I write this in the middle of fixing a(nother) mistake. I originally thought this specimen was Temnothorax nylanderi, collected well outside of its known range, and had started to pursue this, involving other people.

Instead it is Temnothorax saxonicus and I'm feeling quite sheepish. What's especially silly is that I collected T. saxonicus again just down the road from this specimen and had no problem with the identification.

I had taken these photographs and was sorting them out when I realised that the head was the wrong shape for T. nylanderi. On checking my measurements I discovered that I had originally incorrectly measured the head width. Thus, instead of the head length being less than 1.090 times the head width, the head was longer, which clearly made this T. saxonicus.

T. saxonicus is a rarity in Germany and is listed as 'highly endangered' (RLD2). The only place I collected it was just west of Poikham, Bavaria, though there is a slim chance that I may have other specimens unidentified. Seifert has told me that he expects this species in any comparable habitat along the river Donau (Danube).

German ant collections

Another place visited; another list of ants collected. This time the area covered is a small part of Bavaria, as a result of a visit to the University of Regensburg. This list will develop over the next few weeks, as I have numerous specimens to look at. Once I have identified everthing I will send a full list of the records to the university and to any other interested parties.

It is possible to accurately identify some of the species listed in the field, so not all were actually collected. Some of them were collected by Marion Füßl, who found many species before I did and thus proved to be a very useful person to have around! Others were collected with a group of researchers from the university, who very kindly spent their public holiday showing me around. Yet more were collected by Christiane Wanke over the past few years and passed to me to identify.

Though I was not aiming specifically to collect rare species, the letters in red relate to species the German Red Data List (from: Seifert, 2007).

Dolichoderinae
     Dolichoderus
          quadripuntatus ^RLD3
Formicinae
     Camponotus
          ligniperda
     Formica
          cunicularia
          fusca
          pratensis
          rufa
          rufibarbis
          sanguinea
     Lasius
          alienus
          brunneus ¹
          emarginatus
          flavus
          fuliginosus
          niger
          platythorax
     Plagiolepis
          vindobonensis ^RLD2
Myrmicinae
     Leptothorax
          acervorum
     Myrmecina
          graminicola
     Myrmica
          lobicornis ^RLD3
          rubra
          ruginodis
          rugulosa
          sabuleti
          scabrinodis
          schencki ^RLD3
          specioides ^RLD3
     Solenopsis
          fugax ^RLD3
     Stenamma
          debile
     Tapinoma
          erraticum ^RLD3
     Temnothorax
          affinis
          corticalis ^RLD2
          crassispinus
          interruptus ^RLD3
          parvulus ^RLD3
          saxonicus ^RLD2
          tuberum ^RLD2
          unifasciatus
     Tetramorium
          impurum

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¹ Colony found containing the myrmecophilous woodlouse Platyarthrus hoffmannseggi.

Rickia wasmannii

Fairly regularly something comes along and completely stumps me, but it doesn't normally happen with European ants.

I thought I knew Myrmica well, especially M. scabrinodis, which is one of the species I most regularly encounter. This Bavarian specimen really has caused me to do a disproportionate amount of work to resolve it's identity.

First of all I wasn't even 100% certain that it was a Myrmica. It has unusually large mandibles and, particularly, it appears to be covered with rather strange clavate hairs. I had to get my BIG eyepieces out to check the tibial spurs on the middle and hind legs (which were dubiously pectinate) and then count the palp segments, which always takes a lot of effort to get the position and lighting good enough to see anything. The result was that it is definitely a Myrmica.

By this stage I had already decided that it had the antennal scape and overall shape of M. scabrinodis, but those hairs were peculiar. I worked my mounted specimen through Seifert (1988) and his new book (2007), both of which suggested clearly that the specimen is M. scabrinodis¹.

I then really started asking questions about those hairs and, once I had thought of fungi as a possibility, I quickly found was seems to be the most likely answer: Rickia wasmannii. This was described from Germany, though I've no idea how common recorded it is. It was only recently collected from Hungary and Romania (Tartally, et al, 2007), and does not appear to be known from the UK. All five specimens in this collection are covered in these little growths on almost every part of their bodies.

I haven't actually confirmed this, but I suspect that species of Rickia are host specific and that R. wasmannii is the only one that is known from Myrmica sp. However, if anyone has any additional information on Rickia sp. I'd be very grateful to hear about it. In the meantime I will spend a lot more time looking at British Myrmica in the hope that I can get the first UK record of R. wasmannii!

I sure know how to have fun on a Friday evening.

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¹ For those who are interested in such things, the standard measurements and indices used to make the identification were as follows:
     Head length (HL) = 996 µm
     Head width (HW) = 952 µm
          HL/HW = 1.047
     Scape length (SL) = 763 µm
          SL/HL = 0.767
     Minimum distance between frontal carinae (FR) = 310 µm
          HW/FR = 3.071
     Maximum distance between frontal lobes (FL) = 443 µm
          FL/FR = 1.428
     Length of propodeal spines (SP) = 310 µm
          SP/HW = 0.311
     Petiole width (PE) = 266 µm
          PE/HW = 0.279
     Postpetiole width (PP) = 376 µm
          PP/HW = 0.395