2nd UK record for Sciocoris homalonotus at Chipstead Downs!

Posted by Graeme Lyons , Sunday, 16 August 2020 11:32

This is the 2nd UK record for Sciocoris homalonotus, that I suction sampled from chalk-grassland at Chipstead Downs on 31st July 2020. That's the short version. Here's the long version.

To really get why it's took me 15 days to figure out that I had the closest you can get to a first for Britain without getting a first for Britain on the 31st July 2020, we really need to go back to this time last year for some background. I was researching the tachinid Gymnosoma nitens, the host of which is Sandrunner Sciocoris cursitans. It's amazing that there are more records for the fly in the North Downs on the NBN than there are the host! I guess it's a lot easier to see. Anyway, I noticed that there was a record for Sciocoris cursitans on the Sussex coast. It was from Gayles Farm by Andy Foster in 2014. A shieldbug I didn't know we had in Sussex. Given that Sciocoris sideritis had been recorded in 2018 in Essex, and given where this record was on the south coast, I thought it well worth Andy checking his specimen. He kindly did just that and it turned out to be just Sciocoris cursitans after all. I still believe this has colonised from the Continent though and not from the north. I went down and had a look last September but had no joy there.

Fast forward to summer 2020. I have been commissioned by Andy Keay to survey invertebrates of Chipstead Downs and (to a lesser extent) Banstead Woods in Surrey, on behalf of the local authority. On the 31st July, I completed my third visit and Laurie Jackson also came with me. I suction sampled what I assumed was Sciocoris cursitans from a steep, east facing patch of tightly grazed chalk-grassland with broken turf. I vaguely remember thinking it was large at the time but given that the North Downs is the known stronghold for this species, and that there is a dot on the map for Chisptead, I recklessly took some photos with TinyRecorder and published them as the Sandrunner! Will have to go back and edit that post after this! If you haven't discovered TinyRecorder yet, he's a miniature loser that started following me around at the start of lockdown (or is that the other way around?) https://www.facebook.com/TinyRecorder. This does hugely show the importance of taking specimens, even when you think you know what you've found!

That brings me to yesterday. Rained off from a survey on the Downs I had a slow morning and decided to go and look for Myrmarachne formicaria at the Crumbles. I also met up with my old friend Oli Froom and his son Thomas, I kid you not this 2.5 year old was able to identify Yellow Horned-poppy, Viper's-bugloss, evening primrose, Great Willowherb and Rosebay Willowherb on sight! To hear a toddler asking if he was going to see a Bee Orchid was magical! Anyway, I got a male Myrmarachne really quickly, then also found Neon pictus, Oonops pulcher, Malacoroeris nidicolens and best of all, a new site for Pseudeuophrys obseleta. This puts me on 334 spiders for the year. I said goodbye to Oli and soon after found a Sciocoris that I was convinced was something exciting. They were just so small, narrow, dark and variegated compared to the one that was fresh in my mind from Chipstead. There were lots of them too, in fact I found more dead ones than live ones, here is an example. After some confusing messaging back and forth to Tristan Bantock, it soon became clear that these were simply Sciocoris cursitans but I was left with that undeniable gut feeling that I had found something good. This is a new 10 km square for the site and only the second East Sussex record, not seen since 2014 either. So not too shabby.

Here is the specific habitat. Very brownfield and quite different to the chalk-grassland where the Chipstead specimen was collected.

So driving home, it started dawning on me. Maybe I have this all 'arse about tit'? Maybe these aren't small but my specimen from Chipstead was actually huge. The Sciocoris cursitans from the Crumbles were all about 4.8 mm. I rushed home and got the specimen out of vinegar and measured it, 7.9 mm! How did I miss this! Here they are side by side.

I messaged Tristan again with this photo and got back "!!!". I knew I was on to something at this point He emailed me a paper he co-authored and it slowly became clear that this was actually Sciocoris homalonotus. First recorded in Kent in 2016 by Harry Kenward on the 7th June. As Tristan told me, this is a big complicated genus in Europe. So we now have three species of Sciocoris in the UK! It's well worth looking through any you might find for the more interesting ones. Larger with pedunculate eyes being features of homalonotus. I have ordered 'Les Punaises Pentatomoidea de France' after getting in this pickle. So this is a new record for Surrey. There was me thinking I'd found something to close the gap on Surrey (East Sussex has the 4th highest species list, Surrey the 1st). 

A massive thanks to Tristan for putting up with my confusion and to Andy Keay for the work!

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