Southern Marsh Orchids

Southern Marsh Orchids

Sunday, 12 July 2015

Belated Post

This is a very belated post; delayed by the need to revisit the site in question and verify things with people of more expertise than me.

Having run my moth trap for the bioblitz, at Gwyl Taf nature reserve,  Edwardsville, near Merthyr Tydfil, on the 11th June, I took a couple of micro moths home for a closer look and then on the morning of the 12th, took them back to the site to release and photograph them. Having had only 90 minutes sleep, I didn't stay there long, but took a few of photos of some things I noticed, including a dark, bluey green planthopper.

Original Adult, on Dock 

With the photos up on the computer, I went onto the British Bugs website to try to identify the bug, but the only one that resembled it at all and in fact was a close match, was Sonronius dahlbomi. Checking the distribution, it seemed that there  were no records for Wales, the main distribution being confined to the central belt of the country, from the South coast to the north east.

Map Courtesy of the NBN Gateway

I contacted the authors of British Bugs and received a reply from Joseph Botting, who agreed with my identification and said that he finds them at a site in Llandrindod (Welsh records after all). The given foodplants are Willowherbs and Raspberry, but Joseph was finding his on Hogweed, as were a couple of German experts he was in contact with, so he asked me if I could perhaps revisit the site and look for nymphs, to try and establish an association with a particular foodplant at my site.
On the 21st June, I managed to find the time to pay the site a visit and quickly found both adults and a small number of what I thought were probably the nymphs of that species (none illustrated on the British Bugs website) and as I had not been asked to collect specimens, I just took photos and made notes.
The nymphs were found on various plants, including Rosebay Willowherb, Raspberry and Bramble. I searched for Hogweed, but there didn't appear to be any on the site. Having spent a couple of hours searching the vegetation at the original site, I saw more Raspberry and Willowherb growing fairly close by and closer to the river Taff, so I wandered down there and found a path with mainly bracken on one side and a mixture of Bramble, Raspberry, Rosebay Willowherb and some bracken on the other, but immediately bordering both sides of the path were lots of small plants (up to 20cm tall) of Himalayan Balsam, and it was on these that I found dozens of adults and nymphs of S. dahlbomi. I checked the Raspberry, Bramble and willowherb, but found none on them. It was obvious, that where Himalayan Balsam was present, S. dahlbomi preferred it to whatever else might be on offer.

Adult on Himalayan Balsam

Adult on Himalayan Balsam

Nymph on Bramble

Nymph on Himalayan Balsam

Path with small plants of Himalayan Balsam

A discussion ensued between Joseph Botting, Tristram Bantock (British Bugs) and Alan Stewart, the national recorder for this group, about food plant preference and habitat requirements, the conclusion bein that it is prbably fairly polyphagus, with habitat being more important, as it seems to prefer damper sites.

So Sonronius dahlbomi: new for VC41 and only the second known site for it in Wales. Not bad for a quick photo, taken on a bleary visit.

As a bonus, while searching for S. dahlbomi nymphs, I came across this nymph of Speckled Bush Cricket, the only cricket I have ever found up here in the valleys, which is a little puzzling.

Speckled Bush Cricket Nymph


  1. Very interesting Mark and certainly one to look out for - posting all those photos will be helpful to the rest of us. Given the habitat and foodplant associations one would expect it to be fairly widespread, unless it has only just arrived.

  2. I've looked for it at a few sites in the Cynon valley that looked similar and seemed suitable, but without success.

  3. Ditto in Hailey Park, Cardiff this lunchtime. Plenty of balsam, hogweed and bramble but no sign of the bug.