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Black-spotted Longhorn Beetle

An occasionally found longhorn beetle who feed on flower pollen and whose larva feed on rotting  tree stumps.



  • Rhagium mordax: the black-spotted pliers support beetle

    Post date: Friday, 26 June, 2015 - 00:00
    Longhorn beetles are not that common so it is always a bit of a thrill to find one, especially one you have not seen before. This one, that goes under the catchy name of Rhagium mordax, was on rowan blossom at the Arne RSPB reserve. 
    It was amazing that this beetle, once aware of my intruding camera lens (and I admit it was very close), just dropped off of the flower to the ground and there, against the moss, it was so well camouflaged it took me a little while to find it again. This seemed to be a pretty effective safety device. I felt a bit guilty at first thinking it had a long climb back up to the blossom but of course it can fly so I am sure it was not long before it was tucking in to its lunch again.
    This species lays its eggs on stumps and fallen trees and that is precisely why you will see a lot of dead wood as you walk around the Shipstall area of the reserve. Conservation measures do work!
    Wikipedia suggests the common English name for this species is the black-spotted pliers support beetle! I think Rhagium mordax is easier to remember!


Common Name Black-spotted Longhorn Beetle
Alternative Name(s) blackspotted pliers support beetle
Scientific Name Rhagium mordax
Species Group Longhorn beetles
Interest Level
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Identification Notes
Primary Habitat
Preferred Environment
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Additional Identification Notes
Similar Species

The records for this species have been organised into reports, charts, maps and photos. Click a pic below to see the detail:

Notebook Distribution Map Sites List Some Charts Some Photographs Recent Records Guidance Notes

To see related species click here: 

Longhorn beetles