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You can choose your friends but not your family, right?

On this site there is a brief guide to families of UK beetles which we think includes a lot of information and might even be useful when trying to place a specimen in the correct family. We are actually proud of this little page because it is a compromise which, once decided upon, saved us a lot of stress and work. The original intention was to write a key to the families, suitably illustrated and with lots of practical advice for beginners etc, but this, we soon realized, was not the way to place beetles into the correct family. Even a superfamily key is difficult, or maybe not so for those well-versed in the jargon and with a good understanding of insect morphology, but for the rest something of a nightmare. A fundamental difference between Adephaga and Polyphaga, and this is basic stuff for coleopterists, is the presence or otherwise of notopleural sutures. (Ok, so Myxophaga have them as well, but that’s just being pedantic) Well, that’s handy, what more do you need? On the other hand most of the adephagan families are straightforward and easily recognized, and the last thing you need to do is look for notopleural sutures. If you just want to ident stuff it really is not necessary. And if you are working with photos then forget it. They are useless. Most other things that look like Adephaga have different tarsi or antennae or whatever. Furthermore all the adephagan families look distinctive so no problem. The situation is much more involved with Polyphaga, but there are very good pointers such as long palps or close-together antennae or pseudotetramerous tarsi and all the rest of it. Phylogeny being what it is, it should be straightforward to construct a key based on evolutionary divergence, but it ain’t, because of evolutionary convergence and stuff like mimicry and sexual selection and all the other stuff. So at some time in the past weevils and rhynchitids emerged from a common ancestor, but they remain stubbornly similar in appearance and need to be separated by obscure characters. Tough, but they are readily identified from pictures and this is a lot easier than using keys, especially for the beginner. The need to include species into genera and families and a whole load of other groupings appeals to us, and especially to collectors who can label cabinet drawers to reflect the phylogeny of the various groups. Until things change; changing a family name only involves changing a label, but when the limits of a family change it can be more of a problem, and if the cabinet drawers are laid out to cover the Staphylinoidea, then problems will occur with monotonous regularity. Linnaeus used family groupings, and in 1837 Darwin produced an impressive generalized evolutionary tree in his Notebook on Transmutation of Species. And so the stage was set for the next two hundred years or so, and morphological studies have allowed us to produce a very convincing ‘tree’ of life on earth. The UK beetles fit very cosily into genera and families but in the wider world there are many species and genera that do not fit so comfortably into the accepted scheme of things and. for obvious reasons, they are left as ‘incertae sedis’. But families are artificial constructs which, in theory at least, have limits based on either a single character or a group of characters, they sometimes need to be modified but on the whole they are generally inclusive. But what use is this for ident work? Knowing which species belongs to which family is really useful for those with more than a superficial interest in beetles, but constructing a family key in order to place them is often, or even usually, a waste of time when said time would be better spent picture matching. Laricobius erichsoni is a good example of when picture matching would save a lot of anguish, so is Murmidius ovalis, and how many times have I seen Osphya bipunctata described as a cantharid by a well-meaning beginner? There is no short cut to recognizing UK beetles, but the best way to become familiar is to look at photographs of set specimens, and once a basic familiarity is gained then get the hang of things like antennal clubs and which groups have 5-5-4 tarsi etc. The knowledge will come but it really does involve a level of nerdiness that comes naturally to beetle people. Anyway, if you can really appreciate that families are diverse as well as artificial, then you are well on your way. You can then be smug about knowing your families. But the really brave beetler will take families with a pinch of salt because as at the moment we are sequencing genomes like our lives depend on it (and in the longer term they might actually do so), and once we get to grip with what the results tell us there are likely to be a few changes at all levels of classification. And the really good thing about this molecular biology approach is that the results are objective and relatedness can be seen in an absolute sense. But this is still a few years away because we still need to develop frameworks to accommodate the results, the grouping will still be called families because it would involve too much work to change that, but at least the limits of the families would be, dare I say it, absolute, and we would in theory at least be able to place even the most awkward of specimens. So look forward to a few changes and don’t obsess about family keys, it’s not worth the stress.


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