What's in a name? The Tangled History of the "Charnwood Spider"

Like it or not, we need to start with some history (and taxonomy - sorry). 

Mastigusa diversa - a troubled past   See: https://wsc.nmbe.ch/genus/776/Mastigusa

• The name Cryphoeca arietina was first used by Thorell in 1871, having been previously misidentified as Hahnia pratensis by Menge. 
• This species was then identified as Cryphoeca diversa by Octavius Pickard-Cambridge in 1893. 
• In 1908 Pickard-Cambridge renamed it Cryphoeca recisam.
• In 1913 after wandering around Sherwood Forest, A.R. Jackson renamed it again as Tetrilus recisus (On some new and obscure British spiders. Transactions and Annual Report of the "Nottingham Naturalists' Society" 60: 20-49). 
• In 1937 Eugène Simon renamed it Tetrilus diversus, and in 1953 Locket & Millidge called it Tetrilus macrophthalmus.
• In 1986 Wunderlich changed the genus (again) to Mastigusa macrophthalma, based on taxonomic priority from the species name Tuberta arietina macrophthalma used by Chyzer & Kulczyński in 1897. 
• Which brings us to the taxonomic revision by Castellucci, Luchetti & Scharff in 2024, which suggested that UK specimens were likely to be a new species, Mastigusa diversa. (See: Charnwood Confusion Continues).

Enter DNA. Based on the results of Castellucci et al, my initial hunch was that UK specimens would end up as Mastigusa arietina. But this is Mastigusa we're talking about, and it's not that simple. M. arietina was about to disappear from the UK Checklist, not having been recorded for 100 years (UK specimens having been called ... M. macrophthalma - see above!). Thanks to the Tanyptera Project at the World Museum in Liverpool, DNA barcoding has now been carried out on specimens from across the UK. One of the specimens has in fact turned out to be M. arietina, but most UK specimens are Mastigusa diversa as predicted by Castellucci et al. But what about the Charnwood Spider? The Tanyptera Project says: 

"Mastigusa (Charnwood) - the DNA was sequenced successfully and at a high quality. ... Following these results, the results of your previous Mastigusa, and the papers you provided us, we are confident that this is likely Mastigusa diversa."

You would hope that this DNA-supported moniker now persists. The spider, nor its Spanish cousins ... doesn't care. 

With grateful thanks to Richard Gallon, BAS Spider Recording Scheme, for organizing this work and the Tanyptera Project at the World Museum in Liverpool for carrying out the DNA barcoding and funding it. 

Castellucci, F., Scharff, N., & Luchetti, A. (2023) Molecular systematics and phylogenetics of the spider genus Mastigusa Menge, 1854 (Araneae, Cybaeidae). Molecular Phylogenetics and Evolution, 107833. 

https://www.sciencedirect.com/science/article/pii/S1055790323001331

 

One (OM) Lens to Rule Them All

The Olympus M.Zuiko Digital ED 75-300mm f/4.8-6.7 gets looked down on by Olympus snobs because it's "not as sharp" as some of the much heavier OM Pro lenses. I've just picked up an excellent used copy of one of these compact, light, cheap (everythng is relative!) lenses. So what do I think? 

For just over £200 I've got a 600mm full-frame equivalent lens which is capable of photographing a bird at the top of a tree, or at closest focus filling the frame with a 10cm long subject. And by clipping a Raynox DCR250 lens on the front I can get 1.5X magnification, filling the frame with a 1.5cm long subject. My reason for buying this lens is not to photograph birds though :-)  This is the lens I want for photographing flying insects - dragonflies, butterflies, hoverflies - if only there were some flying insects around at present! 

But is it sharp enough? I'll let you decide:

click for larger image

 

The Kleidocerys Conundrum - Resolved?

I've been bothered about Kleidocerys for a while - specifically, is Kleidocerys ericae a separate species from the familiar Birch Catkin Bug, Kleidocerys resedae? See: The Kleidocerys Conundrum. When I cogitated about this two years ago it was obvious that DNA was the way out of the mess. A recent paper spurred me into action - time to find an answer. 

In a nutshell, DNA barcoding is a method of identifying species by sequencing a short, conserved region of DNA. The ideal DNA barcode gene needs to have enough variation between species to tell them apart, but be conserved enough within a species so it can be easily identified. The 5' portion of mitochondrial cytochrome c oxidase subunit I (COI-5P) has become the standard Arthropod barcoding marker. A vast amount of DNA barcode data has now accumulated. At the time of writing, the International Barcode of Life (iBOL) initiative - www.boldsystems.org - has examined 26 million specimens, 21 million of them from Arthropods. Helpfully, the BOLD website makes it (relatively) easy to examine them, so I plunged into looking at the Kleidocerys data. 

CAVEAT: It's been a while since I did this professionally, and even then, it wasn't really my specialism. What follows is my interpretation. Others reading this may well know far more about it than I do, in which case, please let me know. 

A DNA dendrogram - tree diagram (if it was good enough for Darwin to sketch in his notebook, it's good enough for me) - is a visual representation of the genetic relationships between different organisms, or in this case, DNA sequences. Here's the tree for the Kleidocerys COI-5P barcodes:

(click for larger image)

In summary:

• Kleidocerys resedae and K. ericae each form sequence clusters with similar levels of relatedness. This supports the idea that they are indeed separate species.
• Kleidocerys privignus, very similar in appearance to K. resedae but which is said to occur on Alder, also appears to to be a separate species. (NB: one privignus sequence clusters within the resedae sequences (blue arrow) - presumably a misidentified specimen). 

So what does it mean for me? That I probably need to keep looking for K. ericae, although it is possible that it may not occur in VC55. I've been told that K. resedae can occur anywhere, but K. ericae is only found on Erica species (and not on Calluna), that that may help to target the search. It also means that I should probably look for K. privignus - time to target the Alders this year. 

Has this made my life simpler? Nope. When did technology ever do that?

 

DNA Barcoding - where are we, and why should I care?

"Most insects encountered in the field are initially entomological dark matter in that they cannot be identified to species while alive." The DNA revolution in entomology has been progressing diligently in the background but not making much of a splash with civilians. A new paper provides a good overview of the state of the art and makes a prediction: the big leap happens when DNA and AI start working together. 

Illuminating entomological dark matter with DNA barcodes in an era of insect decline, deep learning, and genomics. (2024) Annual Review of Entomology, 70: 185-204 https://doi.org/10.1146/annurev-ento-040124-014001

Abstract: 

Most insects encountered in the field are initially entomological dark matter in that they cannot be identified to species while alive. This explains the enduring quest for efficient ways to identify collected specimens. Morphological tools came first but are now routinely replaced or complemented with DNA barcodes. Initially too expensive for widespread use, these barcodes have since evolved into powerful tools for specimen identification and sorting, given that the evolution of sequencing approaches has dramatically reduced the cost of barcodes, thus enabling decentralized deployment across the planet. In this article, we review how DNA barcodes have become a key tool for accelerating biodiversity discovery and analyzing insect communities through both megabarcoding and metabarcoding in an era of insect decline. We predict that DNA barcodes will be particularly important for assembling image training sets for deep learning algorithms, global biodiversity genomics, and functional analysis of insect communities.

This set me thinking .. (contd)

 

Entomology Update - January 2025

Only a limited amount of entomology from me this month - the weather not helping - but lots of updates. 

Ants - Naturalists Handbook

Should I buy more books? :-)

What *another* camera? Part 2: All out on OM

This is a long and detailed post about photography (macrophotography specifically), you can skip this if you're not interested.  Also nerdy: In Praise of the Flying Nun.

Diptera for the Desperate

An unexpected find in the garden.

Parasitic Pink Pom Poms

You might think day-glo pink fungi would be hard to overlook, but this one isn't often recorded. 

UPF - Ultra Processed fertilizer

A new research paper helps to explain the lack of biodiversity in hige swathes of VC55. 

It's not the dogs fault

Since the pandemic the number of dogs has exploded, and with that, the amount of environmental harm being caused. II don't blame the dogs for this... 

Finally some good news

2025 begins on a bright note with new life breathed into the UK Springtail Recording Scheme. 

If you'd like to see *lots* more photos, I post them regularly on my Bluesky account: https://bsky.app/profile/ajcann.bsky.social