2019 - My Year In Spiders

In 2019 I recorded a total of 354 individual spiders representing 103 species, all from VC55 (Leicestershire and Rutland), 29% of the County list. Figure 1 shows where and when I recorded. This year I tended to roam further afield in summer and stuck closer to home in winter:

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Figure 2 scratches beneath the surface to reveal more about these patterns:

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Panels A and C largely represent the expected phenology of spiders, particularly the presence of mature adults which can be identified. It's worth noting that February, although a natural low point in the phenology, is artificially depressed because other commitments meant I was not able to do much field work at this time. October is a little surprising. We have had a warm autumn which means the traditional phenology has been extended, but the heavy rains from mid-September onwards (the wettest ever autumn in the East Midlands) put a big dent in recording effort with roads flooded and some sites too dangerous or difficult to reach. Panels B and D explain much of the pattern seen in panel A. Visits per Month normalizes for recording effort and also reflects the impact of autumn flooding. However, the autumn rising trend of Species per Visit noteworthy - this points to a mild autumn with few frosts.

Target for 2019? I'm thinking at least 500 specimens and 33% of the County list. For the record, my 2019 VC55 Year List is:

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Agelena labyrinthica
Amaurobius fenestralis
Amaurobius similis
Araneus diadematus
Araneus quadratus
Araniella cucurbitina sensu stricto
Bathyphantes gracilis
Cheiracanthium erraticum
Clubiona brevipes
Clubiona comta
Clubiona corticalis
Clubiona lutescens
Clubiona pallidula
Clubiona phragmitis
Clubiona reclusa
Clubiona terrestris
Coelotes atropos
Cyclosa conica
Diaea dorsata
Dictyna uncinata
Dicymbium nigrum/brevisetosum agg.
Diplocephalus latifrons
Diplostyla concolor
Dismodicus bifrons
Drapetisca socialis
Enoplognatha latimana
Enoplognatha ovata
Entelecara acuminata
Episinus angulatus
Erigone atra
Erigone dentipalpis
Ero aphana
Ero furcata
Evarcha falcata
Floronia bucculenta
Gnathonarium dentatum
Gonatium rubellum
Gongylidium rufipes
Harpactea hombergi
Heliophanus flavipes
Hylyphantes graminicola
Kaestneria pullata
Larinioides cornutus
Lathys humilis
Lepthyphantes minutus
Linyphia hortensis
Linyphia triangularis
Maso sundevalli
Metellina mengei
Metellina segmentata
Micrargus herbigradus
Microlinyphia pusilla
Microneta viaria
Monocephalus fuscipes
Neottiura bimaculata
Neriene clathrata
Neriene montana
Neriene peltata
Nigma walckenaeri
Nuctenea umbratica
Oedothorax fuscus
Pachygnatha clercki
Pachygnatha degeeri
Paidiscura pallens
Parasteatoda lunata
Parasteatoda simulans
Pardosa amentata
Pardosa saltans
Philodromus albidus
Philodromus aureolus
Philodromus cespitum
Philodromus dispar
Pholcus phalangioides
Phylloneta impressa
Pisaura mirabilis
Platnickina tincta
Pocadicnemis juncea
Porrhomma microphthalmum
Porrhomma pygmaeum
Pseudeuophrys lanigera
Psilochorus simoni
Savignia frontata
Scotophaeus blackwalli
Selimus vittatus
Steatoda bipunctata
Steatoda grossa
Stemonyphantes lineatus
Tegenaria duellica
Tenuiphantes flavipes
Tenuiphantes tenuis
Tenuiphantes zimmermanni
Tetragnatha extensa
Tetragnatha montana
Tetragnatha obtusa
Theridion mystaceum
Theridion pictum
Theridion varians
Tibellus oblongus
Uloborus plumipes
Walckenaeria acuminata
Walckenaeria unicornis
Xysticus cristatus
Xysticus ulmi
Zygiella x-notata

2019 - My Year in Moths

I think of 2019 as a poor year for moths, but the numbers don't support that conclusion. In 2018 I trapped 1646 moths of 160 species in 53 sessions in my suburban garden. In total I trapped for 469 hours catching 3.51 moths/h. In 2019 I trapped 1725 moths of 145 species in 44 sessions. In total I trapped for 367 hours catching 4.70 moths/h. My trapping effort was reduced, partly by other personal commitments earlier in the year and partly by the weather from mid-September onwards. 2019 in a nutshell - more moths but less diversity.

Top 12:

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The standout on this list for me is Dark Arches. I have never seen so many and they are my abiding memory of 2019.


Previous years:

2018: https://ajcarthropoda.blogspot.com/2019/01/2018-year-in-moths.html
2017: https://ajcarthropoda.blogspot.com/2017/12/2017-year-in-moths.html

"Can you recommend a microscope?"

I am not an expert microscopist and this is only my personal opinion. If your opinion is different to mine, good for you. However I keep getting asked "What microscope do you use? and "What microscope should I buy?", so rather than writing out the answer every time, here are my thoughts.

At some point every aspiring entomologist realises that they need a microscope. Some time later, they realize that they need a better microscope .... and so it goes. The sad fact is with microscopes, you pretty much get what you pay for (unless you are able to find a used microscope in good condition). Buying a cheap microscope may turn out to be a waste of money, buying a very cheap microscope definitely will. However, it would be stupid to spend £10,000 on a microscope if you've never used one before.

"What microscope do you use?"
I currently own three microscopes, one compound and two stereomicroscopes. In essence, a compound microscope will give higher magnifications than a stereomicroscope (there are other important differences but I'm not going into the technicalities here). 95% of my microscopy is done using a stereomicroscope but I find that I also need a compound microscope or a regular basis.



My compound microscope is an Apex Practitioner which I bought from Amazon. In recent years there has been a flood of Chinese optics into both the camera and the microscope markets. The very cheapest stuff is crap, but there are some outstanding examples of good value for money, and the Apex Practitioner is one. You can buy better microscopes if you pay more, but I would highly recommend this microscope if you're starting out.

My first stereomicroscope was an Apex Explorer, also bought from Amazon. It's not bad value for money, but after a few months I realized that I needed a better stereomicroscope. I have kept the Apex Explorer for several reasons - it's light, compact and easy to transport, and if I ever needed to I could run it off a battery pack - it's a microscope you could use in the field or take on holiday with you if you wanted to.



After a while I upgraded to a GXM XTL3T101LED trinocular stereo zoom microscope which I bought from OneStopNature. You may be able to find it cheaper elsewhere but you may end up paying more in the long run. I would strongly recommend phoning Richard Campey for a chat about what you want to do with a microscope before you buy anything.



"So that's all there is to it?"
The advantage of a trinocular microscope is that you can couple a camera directly to it rather than fiddle about trying to take photos through the eyepieces. The type of camera largely doesn't matter (for the record, I use a Sony a7RII), but coupling a camera to microscope is not entirely straightforward as additional optics are involved. The lighting you use is more important than the camera. I mostly use a cheap LED ring light but for some subjects I also use the illumination built into the XTL3T and/or additional Ikea Jansjö LED lamps. Diffusion of the light source is important or the image quality will be poor, and since microscope depth of field is very shallow, image stacking and post-processing is needed to get a clear image of a whole insect.

There is one final and important caveat: a microscope is only as good as the person using it. An expensive microscope won't make you a good microscopist. The key thing is experience. If you are able to spend time learning from an experienced microscopist, this will accelerate your progress.

Good luck!

Imagine My Surprise

I've been chasing Philodromus albidus for the last couple of years, certain that they're out there. VC55 is on the north west edge of their historical range, and there is only one previous record for the vice county. In May 1994 Jon Daws collected a specimen from Essendine Churchyard, just yards inside the county boundary, which John Crocker identified as Philodromus rufus. When Segers redescribed P. albidus in 1989 (Segers, H. (1989) A redescription of Philodromus albidus Kulczynski, 1911 (Araneae, Philodromidae) Bull.Br.arachnol.Soc. 8(2): 38-40), Jon Daws changed this record to P. albidus.

In the last couple of years I've had a number of specimens from my own garden I was pretty sure were P. albidus but they were all immature and so this could not be confirmed. I've been taking advantage of the lousy weather for a mad end of year dash through my backlog of specimens and was delighted to find not one but two adult female Philodromus albidus beaten from Oak at Narborough Bog on 28.06.2019. At last, proof that albidus is out there and that VC55 is a stop over on the north westwards march of this species.

Let There Be Light - Why it's harder to be an entomologist than a botanist!

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I recently treated myself to a new piece of kit. I've lost count of the number of hand lenses I have - unlike some people, I don't lose them on a regular basis (never buy a hand lens without a lanyard) - I just like hand lenses! Being a botantist is so easy, you can just hold a specimen up to the light and look at it with your hand lens (sorry)! Inevitably when I'm looking at tiny bugs I'm always working in my own shadow. My new gizmo is a 10X LED Triplet Loupe Hand Lens. It's a good quality (triplet) hand lens with a tiny LED ring light built in operated by a tiny switch (arrow). It's the same size and weight as a regular hand lens but two or three times the price. I haven't had the opportunity to use it much yet, but I know it's going to be good. I took a quick test shot of a Pine Ladybird (Exochomus quadripustulatus) just by holding my mobile phone to the lens. Inevitably a shiny subject such as this gives a reflection, but this was taken in a dark corner with no additional lighting, so I'm pleased with it. I don't like the fact that it has batteries to replace but given that the lights are LED that shouldn't be too often. Overall, a very good piece of kit which I would recommend.

eDNA is here, it's just not evenly distributed

I worked with DNA for decades (although not strictly speaking eDNA - Environmental DNA), but earlier this year a paper was published that changed my world view (Environmental DNA metabarcoding of wild flowers reveals diverse communities of terrestrial arthropods. (2019) Ecology and Evolution, 9(4), 1665-1679 https://doi.org/10.1002/ece3.4809). I am in no doubt that in a generation's time, eDNA will have changed the way biological recording works, but what I struggle to see is what this will mean for the amateur naturalist.

Consequently, I was interested to come across LifeScanner - "LifeScanner employs DNA barcoding technology to identify insects, food, fur, or any animal tissue. Find out what you're eating, what's in your garden, or in your home." As far as I can make out, the service is only available in the USA & Canada. It's not clear to me exactly what range of taxa the service covers. It doesn't do plants but I'm not clear what arthropods, if any, are covered. Leaving that aside, the price is US$40 for four tests. Would I use a service like this for difficult spiders or springtails which can only identified by their DNA? Possibly, but at 10 quid a pop, not very often.

In the UK the closest thing we currently have is the NatureMetrics Great Crested Newt eDNA service. I'm not aware of any other UK consumer-level eDNA services, but if there are any, please let me know. PCRing your newt soup will cost you £170+VAT, well worth while if you don't want your garden turned into a supermarket car park. NatureMetrics also run a citizen science eDNA project, although I can't figure out exactly what this entails. So it seems that UK arthropod consumer level eDNA on demand is still some way away, but probably not too far. After that, it's all about commoditization and price reduction. And what that will do to field and identification skills is an open question...

Christmas has come early!

On Sunday evening I was going to bed, walked into the kitchen, turned the light on and found ... something crawling across the worktop. At first I thought it was a tiny harvestman, but since that didn't make any sense (it was late!), it had to be a spider. I presumed it must be Pholcus phalangioides but I popped it in a pot and went to bed. Looking at it in the morning it turned out to be a male Psilochorus simoni, although it took me a while to convince myself of that. This species is thought to be of American origin, imported first into France and then into Britain on wine bottles. There are only two previous VC55 records, one from the wine cellar of a very grand country house. I would like to point out that my wine cellar consists of a few bottles from Sainsbury's in the understairs cupboard, and that alone is pretty good evidence that this species is increasing in frequency. The only reason we don't have more records is because it is so easily confused with Pholcus phalangioides (he wrote, without any sense of irony.... ).

Oligolophus hanseni

Oligolophus hanseni is probably not uncommon, but it is difficult to identify, being very similar to Oligolophus tridens. Identification requires either examination with a very good hand lens or a microscope to see the that the trident and associated tubercles are different. Although the trident members of both species are quite small, in Oligolophus hanseni they are normally pale and on close inspection, tipped with black spines. In Oligolophus tridens the trident tubercles can be pale, or the same colour as the body. Oligolophus tridens can have no additional tubercles to the side of the trident and as few as two behind, but in Oligolophus hanseni there are normally more than this to the side and behind. In Oligolophus tridens the two rows of tubercles on the ocularium are often neatly delineated in white, giving the impression of two white eye-rings. In Oligolophus hanseni there are white patches on the ocularium, but these don't usually give the impression of two neat eye-rings. There are only seven previous records for VC55, but in reality I suspect this is quite a common species.

Benchmarking Spider Recording

Recently, I've been thinking a lot about occupancy models for invertebrates (see: Filling the White Holes). Other taxa, notably birds and butterflies (through the BTO Wetland Bird Survey and Butterfly Conservation's UK Butterfly Monitoring Scheme (UKBMS), respectively) have good negative data, i.e. an indication of where species are absent as well as where they are present. For most invertebrate taxa, partly because of lack of resource (recording effort) but mostly because of the inefficiency of recording, all we have are "White Holes" - gaps in the data which are difficult to interpret. The BAS Spider Recording Scheme does not include "negative data" because it's virtually impossible (without DNA approaches) to be certain a spider is truly absent from a particular area. This makes occupancy models difficult if not impossible to derive. The alternative is to fall back to benchmark species as indicators of recording coverage.

Following Filling the White Holes I had an interesting online chat with Geoffrey Hall who introduced me to the idea of axiophytes (it's a botany thing). BSBI gives the following criteria for axiophytes:

• 90% restricted to these conservation habitats
• Recorded in fewer than 25% of tetrads in the county

It seems that Pliny made it up (as so many other things) in his "Natural History". As far as I can tell, neither axioentomos nor axioarachnos exist, so I've just made up two new words (take that Pliny). The point is that axiowhatevers focus attention on presence (even if it is rare presence), rather than absence, so I still tend towards the idea of using a "universal" benchmark species rather than an axiomatic one. Clearly, the choice of a benchmark species is crucial. For springtails, I am happy to use Orchesella cincta, widely acknowledged to be the commonest species of springtail in lowland Britain. I would be amazed if this species was not present in every quadrat in VC55, it's identifiable in the field with no need to put it under a microscope. For spiders it's a little more complex. The obvious choice is Araneus diadematus. While this might seems to be the most obvious choice, it's only the 4th most commonly recorded species in VC55 (n=724) with only 39% of the count of the most frequently recorded species (Tenuiphantes tenuis, n=1,849). I'm pretty sure that this does not reflect the actual situation, but rather recording bias/snobbery (of which I am probably guilty). While the ubiquity of this species is a good reason to think that this is a valid choice, I needed to test the hypothesis. As a starting point I used quadrat mapping - arbitrarily dividing VC55 into a grid and looking at the number of records within each section. A 25x25 grid worked but the the intervals were a bit small and a 10x10 grid is more informative (all VC55 Spider records to end 2018):


The grid for Araneus diadematus looks like this:


To make sense of this, I converted the distributions into histograms:


The distributions look look similar, but to be sure, I ran some further analysis:


While there is a correlation between the Araneus diadematus distribution and the overall VC55 spider records dataset and this is statistically significant (p = 4.49e-11), it's not a great fit (R² = 0.48). In contrast, when I run the same exercise on the benchmark species I use for normalizing springtail recording effort (Orchesella cincta), I get an R² value of 0.87 (p = 2.2e-16), so that's a much better fit from a dataset which is nearly ten times smaller than the VC55 spider data. So I conclude that Araneus diadematus is a valid benchmark for VC55 spider recording - but it's not a great one. If you can think of a better candidate benchmark species, please let me know.


Acknowledgements:
All data Copyright Leicestershire and Rutland Environmental Records Centre.
Data visualization performed using the R platform, v. 3.6.1 (R Core Team (2014) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org).
J. Cann for assistance with data visualization.

Rainbow Dust [Book Review]

Rainbow Dust: Three Centuries of Delight in British Butterflies
Peter Marren
Vintage, 2016
ISBN: 1784703184

Cover blurb: "Rainbow Dust explores the ways in which butterflies delight and inspire us all, naturalists and non-naturalists alike. Beginning with the author's own experience of hunting and rearing butterflies as a boy, Peter Marren considers the special place of the butterfly in art, literature, advertising and science, and, latterly, our attempts to conserve them. Rainbow Dust takes in the controversy over collecting, the women who studied them and the curious details that lead to butterflies being feared as well as loved. This is a celebration of butterflies; one shot through with a sense of wonder but also of sorrow at what we are losing."

Peter Marren is now a highly respected nature writer best known for the excellent Bugs Britannia and Chasing the Ghost: My Search for all the Wild Flowers of Britain. Although I enjoyed reading Rainbow Dust and learned a lot from it, this is very much in the old school of nature writing, and personally, I enjoyed The Moth Snowstorm more and would recommend that over this book. Nevertheless, Rainbow Dust is still a good read and I recommend it.

Catching the red eye

The glowing red eyes of Drymus brunneus staring back at me from the leaf litter at Charnwood Lodge. It's not as scary as it looks, partly because it's a trick of the light, but mostly because this 4mm long ground bug feeds on mosses and fungi.

Scorpions at Charnwood Lodge?

Neobisium carcinoides

Actually no, but there are pseudoscorpions, related to true scorpions but in a separate Order of arthropods. Like true scorpions they are venomous, but they have venom glands in their chelicerae (pincers) rather than a sting in the tail. The good news is that at only 2-3mm long, they are completely harmless to humans, although not so to the springtails, mites, nematodes and other tiny organisms on which they feed. On a recent trip to Charnwood Lodge I found abundant Neobisium carcinoides in the leaf litter at two different locations. There are more than 3,300 species of pseudoscorpion worldwide, with more being discovered on a regular basis. Most live in leaf litter, moss and soils but some live in houses, such as the Book Scorpion, Chelifer cancroides, which feeds on booklice and so helps to preserve your library!


Charnwood Lodge

Neobisium carcinoides was last recorded at Charnwood Lodge in 1968. Although this species is easily overlooked I am surprised that it has not turned up in the many invertebrate surveys which have been conducted since then. The first County record dates from Buddon Wood in 1929, and John Crocker recorded it regularly on Charnwood in the 1960s. The most recent County record is from Beacon Hill in 2017 but like so many soil arthropods, this is very much a neglected group of organisms and they are undoubtedly widesprerad across the County. Please keep your eyes open for these tiny marvels!

Filling the White Holes

I'm growing increasingly obsessed with data that isn't there... Earlier this month Dom Greaves used the phrase White Holes on Twitter:



It stuck in my mind and I haven't been able to shift it. Previously, I've used R to plot heatmaps of VC55 (Leicestershire and Rutland) spider records (all VC55 spider records (>43k) to end 2018, data copyright Leicestershire and Rutland Environmental Records Centre) (click images for larger versions):



However, the problem with heatmaps is that they inevitably focus attention on where the data is, rather than where it is missing. As an attempt to try to switch the emphasis I tried quadrat mapping - arbitrarily dividing VC55 into a grid and looking at the number of records within each section. Initially I tried a 50x50 grid but with 43,000 records, that choked my computer. A 25x25 grid worked but the the intervals were a bit small and a 10x10 grid is more informative:



Conveniently, R gives the record counts for each tile:



and plotting a histogram of the counts draws attention to how skewed the distribution of records is. Result!



The method isn't prefect. The tiles and hence the counts are of unequal area where they overlap the VC55 boundary, but I don't know how you get around that, with the possible exception that plotting the data by parish rather than by quadrat might be better?

The other place I'm currently stuck is trying to turn unstructured data into occupancy models. This is another White Hole Problem, but one that continues to defeat me.


Acknowledgements:

• All data Copyright Leicestershire and Rutland Environmental Records Centre.
• Data visualization performed using the R platform, v. 3.6.1 (R Core Team (2014) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org).
• J. Cann for assistance with data visualization.

Gnathonarium dentatum

I'm not entirely sure where I'm going with this, but here's my first attempt to combine focus stacking with HDR.

Gnathonarium dentatum.

The "return" of Uloborus plumipes

Uloborus plumipes, also known as the Feather-legged Spider (derived from the Latin pluma "feather" and pes "foot"), or Garden Centre Spider, is a European species now widely distributed in greenhouses and garden centres worldwide. Believed to have been imported from The Netherlands on plants and first recorded in the UK in the 1990's, this species survives in greenhouses and buildings where the winter temperature is maintained above freezing. In this habitat it appears to play an effective role in controlling whitefly, but they are not commonly found in domestic houses. Although it is now widely distributed across the UK, they are cryptic and difficult to spot as they hang upside down motionlessly in their webs. Their horizontal webs and star-shaped egg sacs are much easier to find than the spiders themselves. Females grow up to 6mm and appear to vastly outnumber males, but this may be because the 4mm males are even more cryptic than the females. This species lacks venom glands and traps prey by entanglement in fuzzy, non-sticky cribellate silk.

The Garden Centre Spider was first recorded in VC55 (Leicestershire and Rutland) in 2001, ironically in a garden centre only half a mile from my home. It was subsequently recorded at Brooksby Agricultural College in Melton Mowbray, once more in a now-defunct Leicester garden centre, and finally in the plant section of a Homebase Superstore on 12/06/2006. The species has not been recorded in VC55 since that date, so, with half the roads and fields in the County underwater, I decided to go and do some fieldwork in warm garden centres. The logical place to start was the original location near my home. The only problem with that plan was that this garden centre no longer exists, having been replaced by a housing estate. However, before redevelopment, the owners moved the garden centre business to a new location in the County, so that's where I headed.

It took me approximately three and a half minutes to find the first one, naturally enough, an adult female. Webs were very much in evidence, and after a bit of search, I also managed to find a juvenile. Home again within the hour. One of the good things about being an Arachnologist is that it allows me to predict the future: if the weather stays this wet, more garden centre visits are in store :-)

Diplocephalus latifrons - why the long face?

"Being honest, I'd finished the earwigs and I was bored so I doodled a few crazy spider designs. I think this one looks cool though and I might make it."
God.

Diplocephalus latifrons - why the long face? There's a good reason why some male linyphiids have these wacky cephalic extensions. During mating, the male approaches the female from the front. Most male spiders use the front legs to try to hold up the female or her chelicerae and stop her biting him. In these spiders, the chelicerae fit into the sulcus (groove) on the cephalic hump, wedging them open and preventing her from sinking her fangs into him. But are female spiders really that dumb? No. The sulcus is rich in glandular tissue and the secretions are actually a form of nuptial gift. Matings where females do not receive these nuptial secretions are less likely to result in successful reproduction. Nice design!

Spider Explosion!

click for larger images

Heavy rain (an understatement) during the last week has washed any remaining spiders off the foliage and the action is now all down in the leaf litter. It's been sift-and-sort all the way this week. I've examined leaf litter from four different sites and the number of Microneta viaria has exploded. I have found them as the predominant species at all the sites I have visited, and at one site, they are all I found! This has solved one mystery for me. For the past few months I have been finding immature specimens of a spider with a grey prosoma and orange opisthosoma I have not been able to identify:



It's now clear that these were immature Microneta viaria and now I can see why there were so many of them! Fortunately, they are easy to identify when mature. Both the male palps and female epigyne are characteristic and the prolateral spine on the inside of tibia1 is also helpful.




Epigyne

I think it's no accident that this has coincided with large numbers of springtails in the leaf litter (particularly Dicyrtomina saundersi) - food availability has spurred mass maturation.

How to do biological recording

An interesting new preprint addresses an issue I've been concerned about for a while, how to control for recording effort in assessing how species are doing (Rapid assessment of the suitability of multi-species citizen science datasets for occupancy trend analysis: https://www.biorxiv.org/content/10.1101/813626v1).

The biggest volume of biological data is recorded by unstructured citizen science schemes. Because the data is collected in an essentially random way, many taxon experts are sceptical about the value of these schemes in accurately reflecting populations in the field. Although the statistics are complicated, the method of the new paper seeks to turn unstructured data into occurrence data, i.e. data where we can be sure (to any specified degree) of the presence or absence of a species in a given time period, or the absence of sufficient data to make a determination. The method to do this is to call each 1km grid square a recording site and to count the number of visits each year, one visit constituting one record by any person in a 24 hour period. From this it is possible to calculate the degree of confidence in the occurrence or absence of a species at the site. Ideally (for high confidence) there would be four or more visits from experienced recorders per site per year, but even in the absence of this, the method provides a way of turning the massive amount of unstructured biological recording data available into findings which are easier to interpret and to place confidence limits on.


(click for larger image)

Unsurprisingly, it turns out that butterflies and moths are the runaway winners, the East Midlands performs creditably, and species which get a lot of publicity do better than those for which there are only a handful of experts who can identify them. Nevertheless, if tools could be developed to enable easy utilisation of the method, this would present a valuable way forwards.


(click for larger image)


Note: R package "unmarked" is of relevance: https://cran.r-project.org/web/packages/unmarked/index.html

Spiders on the Green

Cann, AJ (2019) Spiders on the Green. Natural History Section Newsletter, Leicester Literary & Philosophical Society, Autumn 2019.

Click for larger image:

Electric fields and ballooning in spiders

Morley, E.L., & Robert, D. (2018) Electric fields elicit ballooning in spiders. Current Biology, 28(14), 2324-2330. https://www.sciencedirect.com/science/article/pii/S0960982218306936

Fight!

Had to separate these two last night - it wasn't going to end well (for the big guy).

Pholcus phalangioides vs. Eratigena (Tegenaria) duellica.

Enoplognatha latimana - a new species of spider for VC55

Cann, A.J. (2019) Enoplognatha latimana - a new species of spider for VC55. Leicestershire Entomological Society Newsletter 61, 4-5. 

Click for larger images: 

Talking about Neriene montana

I led a wildlife walk this morning and found myself talking (in some detail :-) about spiders, specifically how Linyphiids hang from their hammock webs. This lady, somewhat surprisingly at eye level in a Scots Pine, illustrated my point nicely.

Neriene montana.

The Munchers

I've been tracking a new site for the invading Rosemary Beetle (Chrysolina americana) in Leicester for the last year. I kept finding larvae and pupae which were difficult to identify definitely but it's taken until now to find any adults. When I checked, someone else had already recorded them at this site - not altogether surprising for a day-glo fluorescent-striped beetle! Truth be told, they don't do that much damage, and the RHS says: "Host plants often survive light infestations without any noticeable adverse affects and so control is not usually necessary ... Hand picking can help to keep beetle numbers below the level at which serious damage occurs". Put the insecticide away and stop the insect apocalypse.

Moth records continue to fall

A Toadflax Brocade (Calophasia lunula) turned up in the moth trap yesterday. It was a very worn specimen, but I suspect it's come a long way. Although they've been turning up in small numbers in VC55 for the past two years I suspect this is a migrant rather than a local. Which set me thinking (on a wet day) about the County moth records.

All VC55 moth records (>68k) (to end 2018) (all data copyright Leicestershire and Rutland Environmental Records Centre, data series to end 2018):


click for larger image


I can break this down to look at VC55 moth families:


click for larger image


With over 68,000 records, this is approaching big data, so - heatmap of all VC55 moth records:


click for larger image


From the heatmap, the contributions of individual (groups of) moth recorders can be seen - as well as the remaining gaps in coverage. However, at least two of the islands point to the traditional VC55 honeypots of Charnwood and Rutland Water.


Acknowledgements:

• All data Copyright Leicestershire and Rutland Environmental Records Centre.
• Data visualization performed using the R platform, v. 3.6.1 (R Core Team (2014) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org).
• J. Cann for assistance with data visualization.