above: Dewick’s Plusia, a new county record © Mike Bailey

2023 has seen an active season for the Bath Nats Moth Study Group. Overnight temperatures are of interest to us as warmer conditions generally result in higher catches in the moth traps and are reflected in the table below.

April was rather unsettled although May temperatures were above average and we had the warmest June on record. However, this was in contrast to July which was the wettest since 2009 followed by an ‘indifferent’ August. This was due to the jet stream being positioned above the UK producing low-pressure systems coming off the Atlantic for us and high pressure in southern Europe. This meant we had to contend with wet and windy conditions whereas southern Europe suffered record high temperatures and forest fires. September though saw a great improvement and equalled the highest average monthly temperature previously reached in 2006.

Until visit 13 the group had encountered 2,239 moths of 286 species.

Visit Date Site Total
1 19/04/2023 The Friary, 10
2 06/05/2023 American Museum, Claverton 30
3 11/05/2023 Paulton 19
4 10/06/2023 Bath City Farm, Twerton 276
5 16/06/2023 Elm Farm, Burnett (visit 1) 295
6 01/07/2023 Great Chalfield Manor (visit 1) 417
7 26/07/2023 Chew Valley Lake 57
8 12/08/2023 Manor Farm, Biddestone 143
8A 12/08/2023 Long Dean, West Yatton 144
9 25/08/2023 Compton Dando 309
10 02/09/2023 Elm Farm (visit 2) 236
11 15/09/2023 Great Chalfield Manor (visit 2) 212
12 21/09/2023 Winsley day search for micros 25
13 25/09/2023 Timsbury 66
Porter's Rustic 10-9-23.jpg

Porter’s Rustic, another new county record © Mike Bailey

Dark Spectacle 30-08-23 .jpg

Dark Spectacle, until recently regarded as quite rare © Mike Bailey

Moths of note included:
Dewick’s Plusia. This is a new county record for this very attractive moth and about 20 were noted in August and September.

Porter’s Rustic. Another new county record but, in contrast to the Dewick’s Plusia, is one of the most non-descript moths that one might come across!

Dark Spectacle. Regarded as quite a rare moth until recently and noticeably increased in numbers last year and this.

Mike Bailey