Deri Woods Moth & Bat Event

With a week of unsettled, stormy weather it was good to see a calm dry forecast for Saturday night though temperatures we’re looking a little cool. The forecast was spot on with overcast conditions but a chill in the air. This was a joint event with the Montgomeryshire Wildlife Trust who were providing a bat walk for visitors. Dan, from the Trust said this of the event:

'The ‘moth-ers’ made sure to get in early and set up a mix of traps, including a white sheet and UV traps, placed in a variety of open and closed woodland, and alongside the river (caddisflies were not in short supply…) While we waited for the skies to darken, attendees brushed up on their bat knowledge by guessing true or false to some batty facts and running around, as well as having a go at being a bat or a moth by playing the ‘echolocation game’! Play was cut short once the first bats started flitting about, which continued to be heard on the bat detectors as we spent the remainder of the evening delicately trapping a variety of ‘worn carpets’ and other marbled dusty delights in plastic pots, and diligently bringing them forth to ‘the lab’ for identification and recording. A fantastic night was had by all, particularly as it stayed miraculously bone-dry all evening!’

Just before starting the moth traps at 7:30pm, the gap in the trees above us was being bisected by several pipistrelle bats, a good sign insects were out and about.

A quick chat to the assembled visitors, including a handful of kids, about moths and the traps we had set up, they were all immediately attracted to the white sheet with their pots at the ready. It wasn’t long before the first few moths were potted, with Red-green Carpet and Barred Sallow being the first. The intricately marked Brick was soon brought back from the white sheet and then our youngest visitor brought back ‘the big one’, a nice Copper Underwing agg. 

Not just moths attracted to light

There was a decent selection of autumnal moths caught including Yellow-line Quaker, Red-line Quaker, Chestnut and the aforementioned Brick and Barred Sallow. The latter species was potted several times and though was the only sallow of the night, it did provide its two colour forms as shown in the field guide. A stunning Canary-shouldered Thorn helped brighten up the evening and wow the crowd.

Barred Sallow - two colour forms

Carpets were further represented by Green, Common Marbled and Spruce Carpets, but it was noctuids that continued to be found. A Dark Chestnut was a nice find, and despite the photo it was heard to be quoted as the best looking Dark Chestnut they’d ever seen. But its not easy photographing moths in the dark.

Dark Chestnut

Micros were unsurprisingly thin on the ground given the cool temperatures with just 3 caught – Acleris laterana, Ypsolopha parenthesella and Pandemis cerasana. Around 10pm it was felt the temperatures had dropped sufficiently that the number of moths had completely diminished, traps along the riverside path having not claiming a single moth throughout the night. However, perhaps the most interesting moth was briefly spotted while packing up, a small bright red-brown fluttering moth landed at the base of a tree and as it continued to flutter its wings a white spot on each wing could be seen, a male Vapourer! The attempt to swipe it with a net was too slow and it was quickly off into the darkness.

So a total of 21 species (full list here) wasn’t too bad given the cool conditions and a nice way to finish this year’s season of events with some very enthusiastic kids and of course some of Sue’s cake!

Finally, a big thank you to all those involved in this year’s events. Specific thanks to Douglas for arranging the timetable and locations, Peter for keeping an eye on the new team as we found our feet and to everyone who joined us at the eight events across the county! 

Happy Autumn moth-ing!

Gavin