Southern Marsh Orchids

Southern Marsh Orchids

Saturday 26 April 2014

Megabunus diadema

I came across this fantastic little harvestman at Craig y Llyn this morning - there were at least 3 individuals crawling about on the rock face in the photo below.

Megabunus diadema habitat, Craig y Llyn

Unfortunately it had already started raining at this point and the photo below was the best I could do. It doesn't show the fantastic spines on the eye turret, but I had a good look at these through my hand lens. There's a great photo showing the eye turret here.

My MapMate copy shows only 3 records in Glamorgan, all from the north of the county and within about 10km of Craig y Llyn. This seems strange as the national distribution map on the Spider Recording Scheme website has plenty of records from lowland southern England.
Glamorgan distribution inc. Craig y Llyn record (from my copy of MapMate, so probably incomplete)


  1. Very nice George! Those eye turrets are fantastic! The SRS map does make you wonder if there are two forms of the species with different habitat preferences.

    I had a Platybunus triangularis in the garden the other day, which is the very early maturing species.

  2. I'm pretty sure I had M. diadema at Parc Slip this week - I was actually going to post a picture on here for someone to id for me. Seeing George's photo it looks like that's the one. I'll post it in a bit for confirmation.

  3. I used to think of Megabunus as uncommon and in rocky places - I was first shown it in NE Carms by Ian Morgan. I now see it widely in Carms, though seldom remember to record it, and it's pretty frequent on the shaded wall of our rural cottage.

    As for SE England, I saw at least one Megabunus on a tree trunk in woodland on a chalk down above Chichester last month whilst looking for epiphytes (Ulota coarctata, George).