Friday, 10 June 2016

All-nighter at Pwll Waun Cynon.

I arrived at Pwll Waun Cynon nature reserve at just after 21:00 and got cracking, setting up my 125 watt Skinner trap and my 15 watt atinic Heath trap. I had just finished when Martin and Martin turned up. The weather conditions were almost calm and with the warmth and humidity, it promised to be a good night. Unfortunately, the midges thought so too and decided to have a rave around the trap lights. Chris Lawrence, one of Carys, the reserve warden's volunteers appeared soon after the traps were started.
Moths began coming to the Skinner as soon as it was switched on and from then until it was switched off, at 02:55, there was a steady stream of them. As well as the midges, the other unwelcome presence was thousands of tiny mayflies, which descended on the trap, only to then die and glue themselves to every surface. The same happened in May 2015 and having collected specimens, it was identified as Caenis rivulorum, by Steve Omerod and Craig Macadam.

Being one of the national Moth Nights, this year's target was the Hawk-moth and we did indeed have two species: nine Poplar Hawk-moths and seven Elephant Hawk-moths. We had a total of 36 Diamond-back Moths, but they were the only migrants.

The Miller
Female Dingy Shell, in characteristic wings closed pose.
Chris left after midnight and Martin Bevan, having work the next day, left reluctantly at around 01:00, leaving me and Martin Bell. We ran the Skinner until 02:00, then sorted through and logged the catch, finally switching it off at 02:55, when we moved on to the Heath trap to sort that out.
The final score between the two traps was 84 species, with a couple still unidentified.
Martin and I were finally staggering out of there at around 03:45 and when I got home at 04:00, I didn't bother going to bed.

Apart from the moths, as always, there were other points of interst. Earlier in the evening, Martin Bevan had mentioned mysterious holes in Hogweed leaves, so after he had gone, when going to check on the Heath trap, I spotted some small Hogweed plants with holes in their leaves. Turning them over, I found the culprits; these small beetle larvae. As a result of a quick online search, I think these may be the larvae of the Celery Leaf Beetle (Phaedon tumidulus), but stand to be corrected.

Phaedon tumidulus?
The most intriguing find of the evening for me was a yellow coating I noticed on some old pony dung. A closer inspection hinted at it being a minutely spiny fungal crust, but getting down on my belly and up close and personal with it, I could see through the camera lens that is was in fact thousands of minute slime mould fruiting bodies, each with a shiny, globular yellow top, which turn brown as they mature.

Immature and yellow.


Mature and covered with an open web of threads, the junctions of which have
tiny yellow blobs of something. 
I had high hopes of being able to identify this, but online searches have all proved inconclusive, though it may be a pin head fungus (not a slime mould) called Pilaira anomala.

All in all, it was a good and productive night and nice to have the company and assistance of the two Martins and Chris.

My particular thanks go to Martin Bell, for staying the whole night and helping me sort out the catches and pack up the traps. Cheers, Martin; much appreciated.


  1. I went over field tonight too look and found the same beetle grub .

  2. Thanks for the evening Mark, Like you I didn't bother headed off to bed, I managed a morning at work before calling it a day.