‘Moor’ Large Heath

No sooner a request than a response.  This is excellent and appreciated as we would like to build up a library of images of the range of markings exhibited by the species across Thorne and Hatfield Moors.  Please keep the images coming in.

This example from Crowle Moor is different to the Thorne one but only in so far as the spotting is notably more marked.  It shows stronger spotting and is similar to the image shown in Kirk & Melling (2011).  It exhibits the davus’ characteristic of a full contingent of six large hindwing eyespots with the sixth being a double eyespot.

150611 Large Heath Crowle Moor pl

Large Heath, Crowle Moor: June 11 2015. 

Image: Phil Lee

South Yorkshire populations were traditionally considered ‘polydama’ but Geo. Hyde, an experienced Lepidopterist considered by many to have unparralled experience of the species, considered them more akin to ‘davus’.  The Hyde collection of Large Heath can be viewed at Doncaster Museum.

Thomas & Lewington (2010) illustrate the three ‘subspecies’ and the map does show the South Yorkshire population, but disappointingly they fail to mention it in the text despite reference to Tim Melling whose work they acknowledge the account in their book is based upon (as it was in Emmett et. al.)   Large Heath compared to other butterfly species is short lived, Frowhawk offers between fifteen and twenty days whilst Thomas & Lewington offer three to four days, so clearly the window to see these iconic species is now.  The flight period generally extends to the end of July and into August but for the species to do well it needs good weather and the recent spells of prolonged rain can pose a threat to the adults breeding performance.   In addition to weather risk, and the adults avoids too many losses to Meadow Pipit its main predator it will hibernate as a larva which is quite resilient to flooding and and even to being frozen but prolonged immersion for three to four months is considered harmful.  As if all these risks were not enough there is the parasitic wasp Casinaria petiolaris (Gravenhorst) it is also vulnerable to.

Whilst we recognise the usefulness of photography in our quest for identification and particularly in the ‘library’ aspect of Large Heath data, Atropos published an article by Lewington (2011) Artwork versus Photography, Set Specimen versus Natural Posture which offers useful discussion about the merits of the various forms of ‘record’.  In the interim please keep those digital images particularly of Large Heath coming in.



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