andyk's picture

Formica cunicularia ?

Observed: 25th February 2011 By: andyk
London Natural History Society
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Ant - lateral view
Head - dorsal view
Head - ventral view
Propodeal spiracle
Frontal triangle
Hairs on top of prothorax
Ant - dorsal view

Found as a single specimen under dead wood laying on the ground surface. My first live ant of the year!

  • Formica cunicularia
    Confidence: It's likely to be this, but I can't be certain.
    Likely ID
    Formica sp.
    Confidence: I'm as sure as I can be.
Species interactions

No interactions present.


leenestofvipers's picture


Reminds me of watching the film Them! as a child...great shots.

andyk's picture


According to my key (Skinner & Allen, 1996, Naturalists' Handbooks 24), fusca is a black species lacking any hairs on the thorax and lemani, although similar, is found in the north and on moorland in the south. None of the pics of F. fusca show the abdomen to be as pale as this specimen. I agree that this specimen does not have long hairs on the femora of 2nd legs, which would indicate fusca.
As far as I can see, lemani is very rarely found in Surrey, so seems unlikely.

Andy Keay

Syrphus's picture

Both fusca and lemani can be

Both fusca and lemani can be this pale, Andy. It looks absolutely normal to me. The characteristic of cunicularia is red on the head and thorax - they look a bit like mini-wood-ants - though the amount varies. The number of erect hairs on the pronotum of fusca and lemani does vary, which is why it is usual to make an ID on c.5 workers from a single nest.

I don't exclude the possibility it is a very dark cunicularia (it is not a beast I see often), but no-one should give the ID on a single - possibly aberrant - specimen. That is why I made the revision to genus only.



recording wildlife with The Recorder's Year on

andyk's picture

Thanks for that Murdo. I'll

Thanks for that Murdo. I'll see if I can find more specimens.

Andy Keay

norwegica's picture

General appearance

The abdomen appears pale as it looks distended to me - ie probably expanded with fluid (water, sap, honeydew etc, being carried back to the nest) which is stretching the segments apart. If you keep the specimen it may shrink back as it dries out. fusca/lemani vary in colour from almost black to light brown and alomst reddish in some cases. Often some book descriptions generalise to save space.

andyk's picture

Thanks norwegica - perhaps

Thanks norwegica - perhaps the books should make it clear that these species are variable?

Andy Keay

norwegica's picture

All species vary to a

All species vary to a lesser/greater degree, but in a key it needs to be kept brief. A general description of say dark brown or brown-black etc would cover the vast majority of specimens of fusca/lemani, and is usually enough to separate them from say cunicularia in a key (dark forms aside). Also, don't forget different lighting conditions and colour bias in digital images/pc screens can make a marked difference in how colour/tone is perceived in an image. Something to bear in mind when identifying species from photos.

PhilA's picture

Coming late to the party

Coming late to the party here! I agree with Murdo and norwegica, and would also add, to help distinguish the very dark cunicularia specimens from fusca/lemani, that even the darkest cunicularia show veins of lighter (reddish) colouration within the thoracic articulations and on the cheeks ("genae") of the head. Low magnification may sometimes be needed to check this, but the specimen pictured looks completely uniform.