Wednesday, 23 March 2016

Great Silver Beetle

The other day I found a Great Silver Beetle Hydrophilus piceus on the footpath outside the college in Preuilly. It was distinctly poorly and I assume had been hit by a car.
Great Silver Beetles are aquatic and out of the water a dark olive green. In the water however, they are enclosed in a bubble of air which makes them look like quicksilver. The beetles are covered in fine hairs which trap the layer of air.
There are two families of large aquatic beetles, the Dytiscidae and the Hydrophilidae. The way you can tell them apart is that Hydrophilidae have a very prominent pointy keel running between their legs.
Their shape is streamlined and their legs feathered, in order to move through the water. Despite their rather predatory appearance they are mostly omnivorous scavengers (although they will tackle water snails).
They are amongst the largest beetles in Europe and this one measured 5 cm long. It's female.

3 comments:

  1. She's a beauty!
    They are never "happy" on land... she may well have tried to land on a shiny car... or perhaps a shiny plastic surface nearby... and may well have been exhausted or even chilled. In my experience of water beetles and out of water take-off, they seem to find it difficult.
    We get them landing regularly on the "Maggot" before it gets covered... usually screech beetles and water boatmen...and I find that it is necessary to carry them over to the bief...seems to happen most on nights with a strong moon.
    And I found a Great Diving Beetle once in a tiny puddle in a road pothole... again it had landed on a "pond" after a heavy shower on a moonlit night...
    Did you put her into the town pond?

    And today's sidebar advert was for bat detectors...
    in fact it was one of the "amazing Martin"'s adverts for the Anabat detector...
    https://batdetectors.uk/anabat-walkabout-google?gclid=COfwx-ut1ssCFcYcGwod3NwObw
    ...just look at that price!!
    I was in contact with Martin by email yesterday to ask his advice on cutting down the output from the IR on the camera trap.
    Nice guy and very helpful... as is Ron.

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    Replies
    1. I put her in our laundry tub/garden pond, but she has died :(

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  2. I'm not yet used to click on the ad everytime I look at your blog. Once, it was an ad for AirFrance, since I just booked my trip to France. Several times, it was about real estate in a nearby town and today it was about some kind of concrete for repairs. All local, so far.

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