Bwlch Corog, Glaspwll. 28th & 29th June 2024.

 Another two night survey was conducted by myself at Bwlch Corog last weekend, surveying two different aspects of the site.

Friday night was on the higher part of the site, around 300m. This area is degraded peat bog with very small patches of regenerating heather/bilberry and encroaching bracken around the edges. It is severely overrun/smothered with Molinia grass which thrives in the acidic but drier conditions than a healthy bog would provide. Mixed in with this are scrapes and pits for re-establishing bog species communities. It is very difficult to walk across!

Skinner's synergetic trap swimming in Molinia grass. PMcG

One Skinner's 125w MV and three Skinner's 15w Green synergetic were set up for a full night survey. There was a cold breeze blowing and patchy light rain from 2am so conditions were not ideal.

Orthoteania undulana and Mottled Beauty, drawn in from fringe woody/forested areas. PMcG

Glyphipterix thrasanella, associated with rushes, indicating the wetter parts of the bog. PMcG

37 species were recorded, 7 being micro. Emphasising the current grassland state of the reserve was a very large number of Zelotherses paleana (Timothy Tortrix). Straw Dot and Chrysoteuchia culmella were also present.

Saturday night was wet throughout but milder so only three, waterproof green synergetic traps were deployed, located lower down the site where Purple Moor-grass gives way to even lower wood pasture and broadleaf woodland.

Pristine Large Emerald caught in Purple Moor-grass area. PMcG

60 species were  recorded, 7 being micro. Crowd pleasers being the Large Emerald, Lilac Beauty, Green Silver-lines and Gold Swift. The latter three from the wood/pasture area.

Lilac Beauty. PMcG

Green Silver-lines. PMcG

Gold Swift. PMcG

An unusual, dark form of Peppered Moth f. carbonaria was also recorded.

Peppered Moth f. carbonaria. PMcG

An attempt was made on both days during the mornings to attract Welsh Clearwing, using lures at promising Birch trees. They have been recorded at the site but only by exit hole and casing evidence. Unfortunately the weather was not good enough and none were recorded. 

Despite the tricky weather, 25 new species were added to the site record.

Hopefully, another autumn survey will be possible.

Phil McGregor.