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It is a tradition of the Telfer family to hold a biennial gathering in the Brecon Beacons. The naturalist in me wishes that this family tradition had come to be based in a hotspot for wildlife like Purbeck or the New Forest. But the pan-species lister in me knows that I can find species I’ve never seen before wherever I go. Last time I tackled the whitebeams of the Brecon Beacons. This time I got in touch with Chris Owen to see if it might be possible to meet up and look for two of his local specialities: the Ghost Slug Selenochlamys ysbryda and the harvestman Sabacon viscayanum. Chris gave it the thumbs up and I’m so glad he did because the three hours we had in the field on Sunday 28th September will be long remembered.
Jo, Bradley and I pulled in to the car park in Bargoed to meet Chris for the first time. Dave Gibbs was there too which was a nice surprise and made it a proper pan-species listers’ gathering. In emails, Chris had mentioned a few other highly desirable species that he might be able to show us and after dropping down the valley into a jungle of Japanese Knotweed we were soon seeing one of them, the flat-back millipede Propolydesmus testaceus, in good numbers. Ghost Slug took a bit more work, turning logs and stones and rummaging in leaf-litter but Dave eventually found a tiny one, before Chris located a couple of adults. They are uncannily like shelled slugs but from an unrelated family, with an extremely reduced shell and with a bizarre narrow foot like a monorail train. Bradley got this one on his “Poked it!” list.
Chris is very good on his slugs and also showed us presumed individuals of Arion distinctus, hortensis and oweni which gave Dave and I some dissection work for later. But with no sign of Sabacon, Chris decided to take us on to a nearby woodland where he was more confident of finding it. We just rolled a couple of logs and there it was! It’s one of the more unusual harvestmen and one with a restricted range.
Deeper into the wood, we searched in beech leaf-litter for the Lemon Slug Malacolimax tenellus and the centipede Lithobius tricuspis. We saw both species in some numbers. Dave and I were reeling with all these new species in such a short space of time, and all the while Chris kept mentioning other highly desirable species we might find: the three-pronged bristletail Dilta chateri, the slugs Arion cf. iratii and Arion cf. fagophilus (both recent additions to the British list) and the nemertine worm Argonemertes dendyi. My limited time was running out but I already knew that Chris’s patch was worth a much longer visit and that I’d be back to do it justice.
Driving home, I reckoned Chris had shown me 7 or 8 ticks, and I was well pleased with that. I had a few specimens to confirm or identify but no inkling at this stage that my tubes contained two species new to Britain! Read on in part 2.
… of an entomological consultant. Yesterday was a pretty typical day, surveying a site which is proposed for development. I’m not able to reveal the location but it is a site with a mix of unmanaged grassland and secondary woodland. I spent a little over 6 hours in the field, concentrating my efforts on sweeping and beating. It almost goes without saying that I wore full waterproofs throughout though there was sunshine between the showers.
I worked yesterday evening and from early this morning to finish all the identification work and I’ve listed 102 species for the site. It is always my aim to record over 100 species from a day’s survey but I only just scraped over the line yesterday. I would expect more and I’m tending to agree with others who are saying that this is a poor spring for insects.
The list includes one Red Data Book species and five Nationally Scarce species, though, as is so often the case, some of these statuses are in need of revision for species which have become commoner and more widespread. But they are still useful species for assessing the conservation importance of the site.
I was really pleased to find the RDB hoverfly Rhingia rostrata: only the second one I’ve seen after Dave Gibbs showed me one last year. And there were two species which I got the camera out for. They’re just superb beasts and I don’t think I will ever get tired of seeing them!
Coproporus immigrans is a recent arrival in Britain, specialising in woodchip piles, and I’d only seen it on two previous occasions before yesterday. Here it was in quite an old woodchip pile with thistles growing out of it, though it favours fresh woodchip.
It’s not my aim on survey work to look for species I’ve never seen before: it’s about playing to my strengths and giving the client best value for money, rather than trying to get ticks. But I usually manage a few new species and yesterday I cut open a currant gall on oak for the first time to see the larva of Neuroterus quercusbaccarum within. Also, the common mirid bug Dicyphus globulifer was a new one for me, from a group which I’m tackling more seriously since I acquired Suomen Luteet.
|Species (scientific name)||Species (English name)||Conservation Status|
|Oniscus asellus||Common Shiny Woodlouse||None|
|Porcellio scaber||Common Rough Woodlouse||None|
|Nuctenea umbratica||a spider||None|
|Pisaura mirabilis||a spider||None|
|Glomeris marginata||Pill Millipede||None|
|Cylindroiulus punctatus||Blunt-tailed Millipede||None|
|Forficula auricularia||Common Earwig||None|
|Leptophyes punctatissima||Speckled Bush-cricket||None|
|Centrotus cornutus||a treehopper||None|
|Dicyphus globulifer||a mirid bug||None|
|Deraeocoris lutescens||a mirid bug||None|
|Liocoris tripustulatus||a mirid bug||None|
|Miris striatus||a mirid bug||None|
|Stenodema laevigata||a mirid bug||None|
|Harpocera thoracica||a mirid bug||None|
|Anthocoris confusus||a flower bug||None|
|Anthocoris nemorum||a flower bug||None|
|Kleidocerys resedae||a ground-bug||None|
|Pentatoma rufipes||Red-legged Shieldbug||None|
|Paradromius linearis||a ground beetle||None|
|Ptinella aptera||a featherwing beetle||None|
|Euplectus karstenii||a pselaphine rove-beetle||None|
|Tachyporus hypnorum||a rove-beetle||None|
|Coproporus immigrans||a rove-beetle||None|
|Stenus flavipes||a rove-beetle||None|
|Trixagus dermestoides||a beetle||None|
|Athous haemorrhoidalis||a click-beetle||None|
|Agriotes pallidulus||a click-beetle||None|
|Cantharis decipiens||a soldier-beetle||None|
|Rhagonycha lignosa||a soldier-beetle||None|
|Epuraea pallescens||a beetle||None|
|Meligethes carinulatus||a pollen beetle||None|
|Meligethes nigrescens||a pollen beetle||None|
|Byturus ochraceus||a beetle||None|
|Cerylon histeroides||a beetle||None|
|Rhyzobius litura||a ladybird||None|
|Exochomus quadripustulatus||Pine Ladybird||None|
|Propylea quattuordecimpunctata||14-spot Ladybird||None|
|Coccinella septempunctata||7-spot Ladybird||None|
|Cortinicara gibbosa||a beetle||None|
|Mycetophagus piceus||a beetle||Nationally Scarce (Nb)|
|Mordellochroa abdominalis||a tumbling flower-beetle||None|
|Nalassus laevioctostriatus||a darkling beetle||None|
|Ischnomera cyanea||a beetle||Nationally Scarce (Nb)|
|Oedemera lurida||a beetle||None|
|Pyrochroa coccinea||Black-headed Cardinal Beetle||Nationally Scarce (Nb)|
|Salpingus planirostris||a beetle||None|
|Anaspis frontalis||a beetle||None|
|Anaspis fasciata||a beetle||None|
|Anaspis maculata||a beetle||None|
|Bruchus rufimanus||a seed-beetle||None|
|Lochmaea crataegi||Hawthorn Leaf-beetle||None|
|Longitarsus luridus||a flea-beetle||None|
|Crepidodera aurea||a flea-beetle||None|
|Lasiorhynchites olivaceus||a weevil||Nationally Scarce (Na)|
|Tatianaerhynchites aequatus||a weevil||None|
|Attelabus nitens||Oak Leaf-roller||None|
|Aspidapion aeneum||a weevil||None|
|Protapion fulvipes||White Clover Seed Weevil||None|
|Protapion trifolii||a weevil||None|
|Perapion curtirostre||a weevil||None|
|Perapion hydrolapathi||a weevil||None|
|Apion frumentarium||a weevil||None|
|Ischnopterapion loti||a weevil||None|
|Phyllobius roboretanus||Small Green Nettle Weevil||None|
|Phyllobius pyri||Common Leaf Weevil||None|
|Sitona lepidus||a weevil||None|
|Magdalis armigera||a weevil||None|
|Rhinoncus pericarpius||a weevil||None|
|Ceutorhynchus typhae||a weevil||None|
|Ceutorhynchus obstrictus||a weevil||None|
|Trichosirocalus troglodytes||a weevil||None|
|Nedyus quadrimaculatus||Small Nettle Weevil||None|
|Anthonomus pedicularius||a weevil||None|
|Anthonomus rubi||a weevil||None|
|Curculio glandium||Acorn Weevil||None|
|Archarius pyrrhoceras||a weevil||None|
|Gymnetron pascuorum||a weevil||None|
|Neuroterus quercusbaccarum f. sexual||Currant gall causer||None|
|Biorhiza pallida f. sexual||Oak-apple causer||None|
|Lasius brunneus||Brown Tree Ant||Nationally Scarce (Na)|
|Lasius niger sens. str.||an ant||None|
|Myrmica rubra||an ant||None|
|Myrmica scabrinodis||an ant||None|
|Bombus hortorum||Small Garden Bumblebee||None|
|Bombus pascuorum||Common Carder-bee||None|
|Panorpa germanica||a scorpion-fly||None|
|Rhagio scolopaceus||Downlooker Snipefly||None|
|Beris chalybata||Murky-legged Black Legionnaire||None|
|Microchrysa polita||Black-horned Gem||None|
|Empis tessellata||a dance fly||None|
|Melanostoma mellinum||a hoverfly||None|
|Sphaerophoria scripta||a hoverfly||None|
|Rhingia campestris||a hoverfly||None|
|Rhingia rostrata||a hoverfly||RDB3|
|Neoascia podagrica||a hoverfly||None|
|Syritta pipiens||a hoverfly||None|
|Tephritis neesii||a picture-winged fly||None|
|Pieris rapae||Small White||LC|
|Pararge aegeria||Speckled Wood||LC|
|Monacha cantiana||Kentish Snail||None|
With much less of my time available for natural history since 24th December, I’m making the best of it by staying local and broadening my taxonomic horizons. In fact, today I have spent the whole day studying the wildlife of our back garden and didn’t even make it down to the far end until just before dark! But I have literally left no stone unturned. I have been spurred into action by Andy Musgrove’s “1000 1ksq challenge“: the challenge being to find 1000 species in your chosen 1km square during 2013. It’s a pan-species challenge: invertebrates, vertebrates, plants, fungi, the lot.
I’ve been seriously impressed at how many species people have already racked up for their squares, with Seth Gibson topping the table at the end of January with a mighty 248 species. I’ve also been seriously impressed at the way so many of the participants are taking a truly pan-species approach and boldly tackling Britain’s biodiversity in its entirety. So, the 1000 1ksq challenge has aroused my competitive spirit, and shamed me into trying to identify things that I normally ignore (like lichens, mosses, earthworms, springtails, etc.). Here are today’s results.
First a few photos, then my species lists for today.
Just the ‘famous five’: Armadillidium vulgare, Oniscus asellus, Porcellio scaber, Philoscia muscorum and Trichoniscus pusillus/ provisorius.
Geophilus insculptus – a tick! Common and widespread species.
Microplana terrestris – identified by comparing to Brian Eversham’s photos on flickr. Pretty sure Brian has shown me this species in the past but it wasn’t on my list, so a tick!
Earthworms: identified using the iSpot keys. A completely new group for me and I was amazed at how many species occur in the garden. I identified three but saw at least two others which defied confident identification.
Lumbricus castaneus Chestnut Worm
Lumbricus rubellus Redhead Worm
Eisenia fetida Brandling Worm. A banded worm, common in our compost bin, and curiously malodorous when handled.
Slugs: the MolluscIreland site is very useful for slug identification, with Roy Anderson’s expert ID tips and his photos.
Deroceras invadens (was panormitanum) – thanks to Christian Owen for bringing me up to date!
Arion hortensis/distinctus – still not sure about these.
Arion rufus – with a bright orange foot fringe. Exhibiting a rocking response, which should be less strong than Arion ater though I’m in no position to judge that.
Leistus spinibarbis (Carabidae)
Notiophilus biguttatus (Carabidae)
Tachyporus hypnorum (Staphylinidae)
Lobrathium multipunctum (Staphylinidae)
Xantholinus linearis (Staphylinidae)
probably Tomocerus minor (thanks to Dr Peter Shaw)
Bryum capillare – leaves became “corkscrew-like” when dry.
Brings me up to a mere 117 species for my square.
Nearly at the end of my field season so I should be able to reactivate my blog now. I’ve recently swapped my Panasonic Lumix FZ-38 superzoom camera for a FZ-48 so that I can fit it with a macro adapter. After some truly neanderthal attempts to use my new kit, I eventually sussed it out with help from Mark Skevington, so here are some of my ticks from the last fortnight.
In a 1972 paper on British ground beetles (Carabidae), Carl Lindroth predicted that Harpalus griseus could occur in Britain, perhaps as a migrant, but could be overlooked as a small Harpalus rufipes. And in July 1995, Lindroth’s prediction came true when a single specimen of Harpalus griseus was found at a moth trap in Wimbledon. And then in 2008, Marcel Ashby found three by pitfall trapping in an arable field margin on Croxton Hall Farm, Thetford. I was working nearby in 2009 so I spent quite a bit of time revisiting this field margin, as did Marcel, but despite finding a load of other interesting beetles, including Ophonus laticollis, Norfolk’s first Zabrus tenebrioides for over 100 years, and Norfolk’s second record of Xantholinus laevigatus, there was no further sign of Harpalus griseus. But this year James McGill decided to check it out again and found a single Harpalus griseus on the night of 20th August, the 5th British individual. On a fairly warm Thursday night, Dave Buckingham, Andy Schofield and I joined James to take another look. We did find another singleton Harpalus griseus but tragically it was dead.
The pronotal shape is a good character to separate from H. rufipes, which has slightly concave pronotal side-margins towards the base, and more distinct, less blunt, hind-angles. On the underside, the last three abdominal segments provide the clincher: whereas rufipes is punctate and pubescent at the sides but smooth and hairless in the middle, griseus has a stripe of pubescence down the middle only. Or to put it another way, it has a Brazilian.
I am pretty gutted to have only found one dead griseus on the night, despite collectively checking what must amount to well over 100 Harpalus rufipes. But at least we know that it has been established in that field for at least five years now.
The Top Snail Trochoidea elegans is one of the most distinctive British species, and one of the rarest. It inhabits chalk grassland where there is bare ground and chalky rubble, especially on steep slopes which help to maintain eroding, bare ground conditions. A dry, sunny microclimate will make it feel at home here, as it is an introduction from the Mediterranean, first recorded in Britain in 1890. Michael Kerney’s (1999) atlas shows 4 dots for it, in Kent, Surrey and Sussex.
I have always wanted to see it and got a chance to look at Hawkshill Down (TR 3736 4981), south of Deal on Tuesday morning. It was another damp day with occasional drizzle which for once was absolutely fine with me – perfect weather for snails!
Unfortunately, I was only able to find empty shells, after a pretty thorough fingertip search. And none of them even look like they’ve held a living snail in recent years. In fact, most of them were in the spoil-heaps outside abandoned rabbit burrows which suggests they may have been dug up from down in the soil. I reckon Trochoidea elegans is extinct at this site, as already suggested by Ron Carr after a visit in 2005. Why has it gone? Well, there’s very little bare ground, no livestock grazing, the rabbits seem to have gone, and the scrub and coarse vegetation are moving in.
Should we care? I guess not, for a non-native species. Only it demonstrates a problem that many species face and shows how easily small populations can blink out. It wouldn’t take much management effort to restore the right habitat conditions to that bank but as for Trochoidea elegans – when it’s gone it’s gone.
I would be very interested to hear from anyone with news of the other British populations of Trochoidea elegans: Lydden, Kent; Chaldon, Surrey; and Denton, Sussex.
Compensation was provided in the form of my first Marbled Whites of the year, a superb Lapidary Snail Helicigona lapicida, some Porcellio dilatatus woodlice in debris down an old rabbit burrow, and at the edge of a nearby wheat field some Prickly Poppies and Alsike Clover (tick!). But searching suburban green spaces on hands and knees is a risky business and there was a depressing inevitability to my encounter with a dog turd.
Back when flights were cancelled all across Europe because of the Icelandic ash cloud, I went to the tropical rainforest for a weekend, and popped into the Mediterranean for a few hours on Saturday afternoon! Of course, I was at the Eden Project. Following a very interesting visit on 17th April 2009 with the British Myriapod and Isopod Group (BMIG), I arranged for a return visit on 17th-18th April 2010 for myself and Jo, along with Steve Gregory (woodlouse expert), Darren Mann and Clive Turner plus friends and partners.
You might say that studying the wildlife within a greenhouse is a trivial thing, and not nearly as interesting as studying the native wildlife outdoors. But for me this is about as close as I have come to my unattainable dream of being the first naturalist to step ashore on some undiscovered land, seeing species that no-one has laid eyes on before. And yes … I have seen undescribed species.
Identifying the species that I and others have found in the biomes at the Eden Project is a slow business, and I am reliant on the help of the top experts in Britain and abroad, whose time and expertise is greatly appreciated. This blog gives a summary of work-in-progress.
Thanks to Marc Mappley and colleagues for allowing us to study the invertebrates in the biomes.
The Rainforest Biome: Woodlice
Prior to the 2009 visit, only two species of woodlouse were known from the Rainforest Biome: the pill-woodlouse Venezillo parvus (discovered new to Britain from the Eden Project) and Trichorhina tomentosa (known from several other tropical glasshouses in Britain). Steve Gregory has now got records of a further 12 species detailed below: 4 aliens new to Britain (of which 2 new to science), 6 known glasshouse aliens, and only 2 native British species.
1. A species apparently new to science and probably in the genus Gabunillo. I found 13 (all females) of these small pill-woodlice on 17th April 2009, mostly in the bamboo litter of the Malaysia zone. Steve Gregory passed them onto world expert Stefano Taiti, who commented “Most probably a new species of Gabunillo Schmalfuss & Ferrara, 1983. The only species known in the genus, G. coecus, was described from some caves in Gabon. Your specimens differ in the lobes of the schisma and presence of the single reddish ocellus. For G. coecus males are known”. Several more were found in 2010 but although about 50 examples have been found so far, still no males. It may be a parthenogenetic species.
2. A species apparently new to science in the genus Pseudotyphloscia (a genus close to but distinct from Burmoniscus). Steve had 2 males of this philosciid from soil samples collected in the Rainforest Biome in 2004 and 2005 by the Natural History Museum and extracted by Tullgren funnel. He sent them to Stefano Taiti in March 2010 and Stefano commented: “This is a new species of Pseudotyphloscia Verhoeff, 1928. Up to now the genus includes only one species, P. alba (Dollfus, 1898) with a wide distribution in southern China, Taiwan, Indonesia and Philippines.” On our visit in 2010, Steve located this species in good numbers (including many males) associated with wooden pilings and shorings near the stream.
3. An unknown pill-woodlouse new to Britain. I collected a single specimen on 18th April 2010. It is similar to ‘Gabunillo’ but smaller, yellowish, with dark tapered bristles (rather than colourless clubbed scales), with differently shaped outer margin to first pereonite, and with different uropods, excavated to accommodate an appendage. Steve and I would still like to get Stefano Taiti’s opinion on this one. However, Steve suspects it is just an immature Venezillo parvus.
4. Another philosciid species was collected by NHM in 2003 but just a single female and in a very poor state of preservation. It is coloured chocolate and white, 3.5 mm long. It may not even be possible to determine to genus but is something new to Britain.
5. Reductoniscus costulatus, a small bumpy pill-woodlouse, known from Kew Gardens since 1947. Common in the Rainforest Biome in 2009 and 2010, its second British locality. More recently, Steve has found two specimens from soil samples collected by the NHM in 2003 and 2005.
6. Agabiformius lentus. Once thought to be the most widespread alien woodlouse in British glasshouses, the 3 specimens I found in 2009 (det. SJG) were the first British records since before 1980.
7. Nagurus cristatus. Recorded from Northumberland in 1965 but not since (Gregory, 2009). I found 2 in 2009 and Darren found it in 2010 (all det. SJG).
8. Nagurus nanus. Steve had lots (males and females) of this species (identification confirmed by Stefano Taiti in March 2010) from samples collected by NMH in 2004 and extracted by Tullgren funnel. New to Britain but there is one Irish record of a single specimen from a heated glasshouse in Belfast Botanic Gardens in 1911.
9. & 10. On 17th April 2009, Helen Read found a female styloniscid woodlouse, possibly Cordioniscus stebbingi (det. S.J. Gregory). There is also a single female styloniscid from the NHM soil samples in 2004 which appears to be a different species. There are three styloniscids on the British list, all hothouse aliens. Males are needed to determine which, if any, of these are present in the Rainforest Biome. However, our visit in 2010 didn’t turn up any styloniscids.
11. & 12. In 2009 I found a few specimens of Haplophthalmus danicus near the edge of the Rainforest Biome. This is a common pygmy-woodlouse outdoors in Britain. The NHM samples also contained Armadillidium nasatum, a common greenhouse species in Britain but also fairly widespread outdoors.
The Mediterranean Biome: Woodlice
The Mediterranean Biome is not quite so well-stocked with exotic invertebrates but in 2005, Tony Barber recorded three species of woodlouse, two of them new to Britain: 8 females of an Armadillidium sp. new to Britain (males needed for identification), a single female ?Chaetophiloscia? (again, males needed) and Porcellio scaber (perhaps the commonest British woodlouse; also present in 2010).
In 2010, Steve Gregory was keen to try and find males of the Armadillidium and the ?Chaetophiloscia? He succeeded in finding a male of the Armadillidium which he has provisionally identified as A. assimile.
Steve’s searches also turned up an unfamiliar porcellionid which he identified within the week as Lucasius pallidus, new to Britain, a woodlouse of Mediterranean France and Spain.
Steve kindly showed me the spot where he’d found what turned out to be Lucasius pallidus, and by heaving over a large and deeply-embedded rock, I found some of the ?Chaetophiloscia?, including a single adult male. I have confidently identified this as C. sicula but will get Steve to check it in due course.
The Rainforest Biome had been better worked for millipedes prior to the 2009 BMIG visit, with five species recorded, including the superb Paraspirobolus lucifugus which was discovered new to Britain from the Eden Project and was common in 2009 and 2010.
I didn’t pay as much attention to millipedes as I did to woodlice on the 2009 visit (nor the 2010 visit for that matter) but I did find 12 specimens of a tiny white pill-millipede that seemed likely to be new to Britain. Helen Read also found one on that visit and quickly pinned it down as Amphitomeus attemsi, new to Britain (Barber et al., 2010).
Better was to come in 2010 though when I found a single small, white millipede by digging down at the side of some damp, rotting, wooden pilings. Now I love the instant thrill of discovering a rarity that you instantly recognise, like the Bee-eater that came and flew about overhead one fine June day on the Deal sandhills. But I also love the feeling of staring at an invertebrate in a state of complete bafflement. Under the microscope, this millipede was like nothing I’d ever seen and after consulting every book in my possession and googling everything I could find, I was still not even entirely sure it was a millipede! Description here. Fortuitously, Helen Read recognised it as a millipede of the Order Siphonophorida, a pantropical group in which she is something of an expert. This is a new Order for Britain, and maybe a new Order for Europe! Unfortunately, they are a taxonomist’s nightmare and the chances of being able to identify my specimen to species are very small. No-one knows what they feed on or what the narwhal-like head-spike is for.
Cylindrodesmus hirsutus is a millipede known from the Palm House at Kew and from a tropical butterfly house in South Yorks as well as from the Rainforest Biome. This and/or a comparable species were found in 2009 and 2010: whitish specimens lacking paranota which seem to be C. hirsutus as well as pinkish-terracotta coloured specimens with distinct paranota which seem to be a different species. Steve is trying to figure this out with advice from Henrik Enghoff.
Anthogona brittanica is an outdoor millipede, described new to science from a male specimen collected at Slapton Ley, South Devon by Steve Gregory in 1993 (Dick Jones had also collected a specimen there in 1983) and still believed to be a British endemic. Lee (2006) mapped it from four contiguous 10-km squares of South Devon. I collected one specimen in 2009 near the edge of the biome and although it is a female, it is probably A. britannica (Steve Gregory, who described the species, tentatively agrees!). It would be good to find a male and clinch this as it would be a significant record of a rare, endemic invertebrate.
Of the three other species known from the Rainforest Biome prior to 2009, Oxidus gracilis was fairly common in 2009 and 2010 but neither Poratia digitata nor Rhinotus purpureus was seen. Later in 2009, after the BMIG visit, Tony Barber discovered Pseudospirobolellus avernus new to Britain and in fact a new family (Pseudospirobolellidae) to Europe (Barber et al., 2010). There is some evidence that species in the biomes change in abundance and it is possible that some have established only temporarily and now died out.
Disappointingly, there are very few beetles in the Rainforest Biome. In fact, I have only found two species, though one is quite an unusual species: the silvanid Cryptamorpha desjardinsii (common in 2009 but less so in 2010). The other was Harpalus rufipes, a very common carabid beetle.
I have found several species of beetle in the Mediterranean Biome but all are common species of outdoor habitats in Britain.
There are lots of other invertebrates in the biomes, and with the need to screen everything carefully as a potential new to Britain or even new to science, it is quite difficult to record across all groups. However, some of the highlights are:
- Australian Cockroach Periplaneta australasiae
- Surinam Cockroach Pycnoscelus surinamensis
- a jumping spider Hasarius adansoni
- a short-tailed whip-scorpion Schizomida sp.
- 5+ species of ants including Hypoponera punctatissima
- big earwigs, probably a species new to Britain
- 4 known species of centipede: Mecistocephalus guildingii, Tygarrup javanicus, Cryptops doriae and Lamyctes caeculus.
- several species of snail including Subulina octona and Striosubulina ‘striatella’
There’s sure to be a lot more to be found, and I know there’s a lot more still to be identified from Darren and Clive’s samples. It would be interesting to have a look round the biomes at night!
Barber, T., Gregory, S. and Lee, P. (2010). Reports on the 2009 BMIG Spring Meeting in Cornwall. Bulletin of the British Myriapod and Isopod Group, 24, 65 – 74.
Those who’ve been in contact fall into two camps: those who think the holes were probably caused by another mollusc, and those who think they were caused by a beetle. But tellingly, all the mollusc experts so far think that beetles of some sort must be responsible, and two have noted that they’ve seen holes like this in terrestrial snail shells in the Mediterranean.
As Richard Wright and others have kindly pointed out, there’s a 2004 book on “Natural enemies of terrestrial molluscs” with a detailed chapter on Coleoptera as predators of terrestrial gastropods by Bill Symondson of Cardiff University. Bill’s response must therefore be the most authoritative that I’ve received but is still a guess: “I would guess that these are the exit holes of drilid beetles, that parasitise many species of snails”.
The great thing about Bill’s response is that it has turned the mystery on its head – it’s not about what’s trying to get in but what’s trying to get out! In support of the parasite theory: (1) there are 5 separate holes – why would a predator need more than one?, (2) the holes are quite evenly spaced as they might be if 5 parasites had partitioned up the snail between them, and (3) one of the holes is right by the mouth aperture so there’s no way it was the easiest route of attack to get IN to the shell.
So, given that Drilus flavescens is the only drilid on the British list and it has been recorded not too far away to the south in Berkshire and Oxfordshire (map here), can we add it to the Buckinghamshire list? Maybe.
Andrew Duff dug up another interesting lead here. This person has lots of Garden Snail Cornu aspersum (formerly Helix aspersa) shells in their garden with one or two neat circular 4mm holes in them. Nobody on the wildaboutbritain forum seems to know what’s caused them but whatever it is must be the same beast that drilled the Grangelands Helix pomatia. However, the garden in question is in Lincolnshire! I could believe that Drilus flavescens exists at Grangelands – a superb calcareous grassland just north of the known range. But I find it harder to believe that Drilus exists in a garden in Lincolnshire!
For a definitive answer, Julia’s going to try and breed the parasites out in 2010.
Meanwhile, thanks to all those who’ve been in touch and if anyone has further suggestions, I’d be glad to hear them.
Alison Woods and Julia Carey found this empty shell of Helix pomatia, the Roman Snail or Edible Snail, at Grangelands, Buckinghamshire on or shortly before 18th February 2009. Julia is well acquainted with this population of the snail and has never seen one, before or since, with neat circular holes in the shell, despite looking at lots of shells. What made those holes? I’ve been puzzling over the specimen for the best part of a year without coming any closer to an answer. Can you help?
There are 6 circular holes in the shell, each of 4 mm diameter. I’m guessing they were made by a predator but why not attack the exposed body of the snail at the mouth of the shell rather than breaking through the shell wall?
The damage to the Helix shell is reminiscent of that caused to bivalves by the marine necklace shells so my best guess is that this Helix was attacked by another mollusc, perhaps the Leopard Slug Limax maximus which is known to be a predator of other slugs at least.
Any and all suggestions gratefully received!