Some of the smallest beetles are ‘must see’ species. Here are three of the best.
|But for its wonderful name, Microdota liliputana or as Roger Key once dubbed it, “The Lilliputian Micro-dot Beetle” would be just another member of the obscenely speciose Aleocharinae subfamily of staphylinids, albeit quite a small one (1.6 – 1.9 mm). However, I have wanted to see it since I first heard about it maybe 15 years ago, and now I have. It was named by Brisout in 1860, 134 years after the publication of Gulliver’s Travels. This female flew into a pan trap in the reedbeds at the RSPB’s Ham Wall reserve in June/July 2009 – the first for Somerset. The traps were run by Donna Harris and Anna Doeser as part of a project on reedbed management for Bitterns.|
Sphaerius acaroides (0.7 mm) probably ought to be called “The Full Stop”, though to be fair there are quite a lot of candidates for that name. It is, taxonomically, the most unique British beetle, being our only member of the sub-order Myxophaga. All our other beetles are either in the Adephaga or the Polyphaga. It has been recorded from a scatter of sites north to Westmorland (map here) but in recent decades has only been found on the wonderful undercliffs at Eype, Dorset and is listed as a Red Data Book species. The trick is to find trickles of water, agitate the mossy vegetated margins knocking any Sphaerius into the water where they become a lot easier to spot and then try to pick them off before they float away downstream. As the name implies, they look very like mites, but have a beetle’s gait. It must be overlooked elsewhere in the country, surely? Finding one is challenging but as the photo shows, carding one with all its appendages on show is even more so!
Finally, Britain’s smallest beetle at 0.55 – 0.65 mm is the ironically named Nephanes titan, or as I like to think of it “The Titan”. It is one of the feather-winged beetles, family Ptiliidae. It’s not supposed to be a rare species but I have only ever noticed it once, while sieving the top layers of a steaming manure heap in the woods north of Isle of Wight Farm, Denham in November 2008.
Ignore the scale bars on the pictures – something went wrong!