The BENHS meeting at the University of Bath went ahead on the weekend of 20-21st April as planned. This was very well supported by over 20 students representing several universities including Bath, 20 BENHS members including the 7 leaders and 3 visitors. The moth component involved both an indoor presentation and outdoor light-trapping for adult moths and beating for caterpillars overnight. This fieldwork took place in Limekiln Wood, which is on the south-east corner of the University campus. This wood looks out over superb rolling countryside with pasture and additional copses. We found carpets of Wild Garlic/Ramsons Allium ursinum along with Wild Arum Arum maculatum and Dog’s Mercury Mercurialis perennis, suggesting that these steep banks have been continuously wooded for generations. Ian Sims and I set up five lights between us, in a line down a muddy track along the east edge of the wood, protected by a boundary hedgerow predominantly of Common Hawthorn Crataegus monogyna and Elder Sambucus niger. Within the strip of woodland we found some large Oaks Quercus robur as well as a big Yew Taxus baccata, together with Hornbeam Carpinus betulus and Sycamore Acer pseudoplatanus. The night sky was clear, with a bright moon which was almost full, and the temperature quickly fell to 6°C once it was dark, with a minimum of 2°C during the night, but at least it was dry and calm. We captured a total of 69 moths, of which 63 were macro-moths of 11 species, and the others were all the Oecophorid Diurnea fagella. The catch included a Water Carpet Lampropteryx suffumata, which arrived early in the night (21.50hrs), an Oak Beauty Biston strataria and 7 Brindled Beauty Lycia hirtaria as well as a March Moth Alsophila aescularia and an Early Thorn Selenia dentaria amongst the geometrids and a hibernated Satellite Eupsilia transversa amongst the more numerous Orthosia species or Quakers (Common Quaker Orthosia cerasi 17, Hebrew Character O. gothica 17, Clouded Drab O. incerta 9, Small Quaker O. cruda 3). Interestingly the lights at the two ends of the line of traps caught notably more moths - 24 macro-moths of 8 species in my Robinson trap with 125W MB/U bulb highest up the hill and 15 macro-moths of 5 species in Ian’s 125W MBF/U bulb on a short pole over a sheet at the bottom of the hill. My identical Robinson trap next down the hill caught only 8 macro-moths of 5 species, my 6W actinic Heath trap in the centre of the line took 9 macro-moths of 4 species and Ian’s Robinson trap below it with a 125W MBF/U bulb took 7 macro-moths of five species. Also of interest, five of the seven Brindled Beauty moths occurred in the trap furthest up the hill and the other two in the actinic trap, showing that species can be localised in abundance within woodland. All of the Brindled Beauty and the Oak Beauty arrived after midnight when Ian and I inspected our traps, topped up the generators and crawled into our cars to sleep until dawn. The students who turned up to inspect the catches in the morning were pleased with the number of moths we had, but these were low catches for the time of year, though not the temperatures. Like other mothing results at this time the catches were evidence that the spring was running at least a couple of weeks later than average, with all but the Satellite in freshly emerged condition and the Quakers still building to peak numbers which are often reached before the end of March.
Ten minutes spent beating for larvae once the traps were set up and running proved futile. The Hawthorn and Elder was only just coming into leaf and any caterpillars on them already would have been mostly in their first instars. The canopy of trees above us was hardly showing any foliage at all, only bare twigs.
During the night we had a Tawny Owl Strix aluco calling, and in the morning a Common Buzzard Buteo buteo mewing and a Chiffchaff Phylloscopus collybita in full song, while a pair of Coal Tits Periparus ater foraged near the upper traps and a pair of Long-tailed Tits Aegithalos caudatus searched the shrubs near the lower ones.
Our grateful thanks to the University of Bath for allowing us to meet at the University and to carry out fieldwork on campus.
Paul Waring
