COLLEMBOLA > SYMPHYPLEONA > Katiannidae

I've read that this particular family is badly in need of taxonomic revision and that the British list is rather outdated, which obviously makes it somewhat difficult to understand the classification currently being used.

On the face of it, Katiannidae includes around 14 species yet, when you start digging deeper, it becomes apparent that only four have actually been recorded in recent years: Sminthurinus aureus (possibly a group or aggregate of species), Sminthurinus elegans and Sminthurinus niger, all three of which are common native species of variable appearance. The other is Katianna schoetti, which is an accidental import from the southern hemisphere that is now associated with the horticultural industry. A further closely related species in the same genus, Katianna australis, has also been discovered, but not as yet officially recorded.

Sminthurinus aureus is a very common terrestrial springtail that frequently occurs on low vegetation and is particularly abundant in the autumn in both wet and dry leaf-litter. It's tiny, barely a 1mm long, and is characterised by having a wholly fused rear end, whereas other British species in this genus have a visible division between the final segments abd5 and abd6. The described form of the species has a uniformly coloured body without dark longitudinal bands or white spots. The colour though is extremely variable, being either greyish-yellow as the individual featured here, or brown or even black.

The variation in colour and degrees of any pigmentation have given rise to named forms and, I have to say, this is where I get confused as this particular specimen was identified as form reticulatus by Frans Janssens who is one of the leading authorities on Collembola. However, another well-known expert refers to Sminthurinus reticulatus as a separate, albeit very closely related, variety with distinctive patterning consisting of three or four bands across the top of the abdomen plus dark lateral bands, which are discontinuous around the posterior end. To my eyes, the specimen here has some vague markings, but none that I would call distinctive. So, I'm not sure if they're the same, or that one is now regarded as a separate species and the other, as featured here, is a variant form that sits between the two.