Thursday, 18 September 2014

Surveying for moths in a lost world (14th September 2014)

The idea of conducting a moth survey in a "lost world" at the Centre for Alternative Technology (CAT) was something that Peter had been working on since May.  The site is part of the disused Llwyngwern slate quarry just north of the main CAT site, now only accessible through a small wet tunnel.  Ideally the survey would have taken place in mid-summer, but the availability of group members and then inclement weather precluded running the event until now.
Logistics - getting 9 traps on site
Four of us arrived on site just before 7pm, giving us about an hour to set things up.  Peter's excellent organisational skills ensured that the necessary transport was on hand to convey the trapping gear from our vehicles, namely a trolley and two rusty wheel-barrows!  

En-route to trap site

However, a fallen tree across the path meant we had to carry everything through the dark wet tunnel in order to set up the traps in the quarry beyond.  Come 8 o'clock and everything was ready for the moths: two 125w MV Skinner traps on the path short of the tunnel, then within the quarry itself two more Skinners and a Robinson trap all with 125w MV lamps, plus four Heath traps (three 6w actinic and one 15w Actinic).

Tunnel entrance
Survey site

It wasn't long before Douglas came back with the first moth of the evening - a dead Atlas Moth (Attacus atlas), a species native to South-East Asia!  We wondered whether some enterprising member of the CAT staff had left it specially for us to find? 
Atlas Moth

British moth species gradually appeared, starting with Flame Carpet, then the first of the two most prolific species of the night - Common Marbled Carpet and July Highflyer.  A single Brimstone Moth was followed by a Tissue; subsequently many of these were found over-wintering on the tunnel walls, as well as three Herald.
Over-wintering Herald
Over-wintering Tissues

The air temperature at the table was holding up quite well, between 13°C and 14°C for most of the evening, but when it rose to nearly 16 degrees surprise was expressed, until we found that Peter's mug of tea was rather close to the sensor!
Micro-moths were being outnumbered 2-1 by their macro cousins, but notable finds were Argyresthia goedartella, Epinotia ramella, Ypsolopha parenthesella and Pandemis cinnamomeana.
Epinotia ramella
Argyresthia goedartella

Ypsolopha parenthesella

Pandemis cinnamomeana

Back with macros, a very fresh Red-line Quaker was nice to see, along with a rather worn Anomalous.  Some late arrivals included a Straw Dot and Fan-foot and at about 1am, as the last trap was being emptied, we found a Purple Bar and a Hedge Rustic.  That took the species tally for the night to 36 (11 micro and 25 macro).

We mused that notable by their absence were many of the usual autumn species such as Autumnal Rustic and the Sallows, but we felt that the site holds enough promise for a re-visit, hopefully in mid-summer next time.
Survey species list
0411  Argyresthia goedartella
0460  Ypsolopha parenthesella
0858  Hypatima rhomboidella
0971  Pandemis cinnamomeana
1038  Acleris laterana
1062  Acleris emargana
1134  Epinotia ramella
1334  Scoparia ambigualis
1338  Dipleurina lacustrata
1340  Eudonia truncicolella
1344  Eudonia mercurella 

1722  Flame Carpet
1752  Purple Bar
1760  Red-green Carpet
1764  Common Marbled Carpet
1769  Spruce Carpet
1777  July Highflyer
1790  Tissue
1862  Double-striped Pug
1906  Brimstone Moth
1913  Canary-shouldered Thorn
2102  Flame Shoulder
2109  Lesser Yellow Underwing
2111  Lesser Broad-bordered Yellow Underwing
2176  Antler Moth
2177  Hedge Rustic
2178  Feathered Gothic
2263  Red-line Quaker
2361  Rosy Rustic
2364  Frosted Orange
2394  Anomalous
2469  Herald
2474  Straw Dot
2477  Snout
2484  Pinion-streaked Snout
2489  Fan-foot


  1. Great report Peter, I relived the survey with the excellent way in which you chronologically noted the evenings events – I won’t forget trudging through that long, dripping wet tunnel for a long time!

    Thanks for doing a good selection of photos too, they all look really good.

    As you have noted, I hope we can get back there next year during the summer months, I feel we have only just scratched the surface and the quarry at CAT still has a lot of mothy secrets yet to yield.


  2. Some cracking photos Peter [as usual] of a challenging but fascinating evening. I particularly like the one of Peter W heading off to the unknown with his wheelbarrow! A highlight had to be the tissue moths in the tunnels.
    Well done Peter

  3. Great report Peter, thanks for posting.

    Looking forward to retrapping the site next year in the summer!