Hypogastruridae and Onychiuroidea

Contrary to Dallimore and Shaw's (2013) 'Illustrated key to the families of British Springtails (Collembola)', it is not a universal rule that distinguishing UK springtails from the families Onychiuridae and Tullbergiidae (together superfamily Onychiuroidea) from UK springtails in the family Hypogastruridae (having eliminated from consideration Neanuridae, Poduridae and Odontellidae), is a simple matter of considering all white (unpigmented) springtails as Onychiuroidea and all non-white (pigmented) springtails as Hypogastruridae.

Rather, there are a few outliers to this general rule – the relatively few but still considerable species of unpigmented Hypogastruridae. Some of these resemble Onychiuroidea, at least to an untrained eye. Of those for which there are photos listed on the global Springtail database, there are at least 5 species of unpigmented Hypogastruridae:

• Ceratophysella succinea
• Ceratophysella armata
• Schaefferia emucronata
• Xenylla grisea (juveniles)
• Mesogastrura libyca

To identifiers with experience, most of these species are quite distinctly different from Onychiuroidea, but Mesogastrura libyca in particular looks very similar to some members of the superfamily. It should also be explicated that many Hypogastruridae species lack photographs on the database and so could also easily also be unpigmented and similar in appearance to some Onychiuroidea.

I therefore urge that caution should be taken when distinguishing Hypogastruridae from Onychiuroidea on the exclusive basis of pigmentation. In cases where appropriate detail is not obvious, observations should be left at order.

Publicado el 05 de abril de 2024 por josscarr