I found more details on Platyrhinus resinosus – which featured on the Natureheads blog last year as a mystery beetle – and was quickly identified at the NHM Bug Forum. Apparently the common name is the Scarce Fungus Weevil.
Natureheads note: Weevils are a type of beetle. Beetles are the most varied set of animals on the planet.
From reading around it seems the larvae feed on fungus – I don’t know what the adults eat. On the Woodland Trust’s Ancient Tree Forum they had some key information:
“The hard black fruiting bodies of the fungi Daldinia concentrica and Hypoxylon spp are remarkably favoured by insects. The precise species of fungus appears not important, rather the hard black medium provided: the scarce fungus weevil Platyrhinus resinosus develops in Daldinia concentrica on ash trees as well as Hypoxylon fragiforme on beech, and other beetles behave similarly, eg Biphyllus lunatus, Litargus connexus, and Mycetophagus atomarius.”
Natureheads note: You might know Daldinia concentrica as the fungus on ash trees called ‘King Alfred’s Cakes’ which resemble oven-burned buns!
How scarce is it?
The Scarce Fungus Weevil is listed as being ‘Nationally Scarce’ and therefore notable. It comes under the category ‘Notable B’ which means it is uncommon in Great Britain, thought to occur at between 31-100 of the 10km squares of the National Grid – or for less well recorded groups, between 8 and 20 vice-counties.
At the NBN Gateway there is a very useful interactive map system, which I used to view the national distribution pattern.
This can’t be complete – it doesn’t have my record! Anyway, there must be hundreds more sightings that people haven’t given to their local environmental records centre, plus many more instances where the weevil wasn’t identified.
So if the nation’s records of Platyrhinus resinosus don’t reflect its true distribution, how about a concerted effort to find more? OK, they hide in fungus, but King Alfred’s Cakes are easy to find. Fancy a cake survey?
Jason Ball @ Natureheads.com