Free Range Pollen

Out and about recently I came across this Chocolate Mining Bee, Andrena scotica, with bulging pollen brushes (scopa), so I put my pollen "skills" into action.

95% of the pollen grains in the sample were the lower, triangular-shaped grains. This is either Bird's-foot-trefoil, Lotus corniculatus, or more likely, Horseshoe Vetch, Hippocrepis comosa, which was present on this site. I can't tell the difference between these two and I'm not sure if it's possible without resorting to DNA. The remaining 5% were Cow Parsley, Anthriscus sylvestris, (the upper oval grain). This makes sense as while the entire site was fringed with Cow Parsley, and while it's not that attractive to bees, the sheer abundance of the pollen would make its absence a surprise. 

So, within my limited skills, it works! The only thing that occurs to me is that I really didn't learn anything in this analysis that I didn't already know from observing the bees on site. It would be worth doing with bees from unknown sites, but a little behavioural observation in the field goes a long way. 

As an aside, I'm also getting good results using dark field illumination for pollen. Can you guess what species this pollen is from (warning: it's a tricky one!)?

Where the bee sucks

Unsurprisingly, the solitary bees I have been working with recently have often been covered in pollen (they have a lot to cram into their short adult lives). I took this female Osmia bicornis from the Geranium macrorrhizum which attempts to overrun my garden (I've never rated it much as a wildlife plant but it has filled a gap which the bees have been very grateful for over the last few weeks). 

 

The large orange pollen grains are obvious, but also very distinctive under the microscope:

My favourite so far is Daisy pollen, Bellis perennis: 

So far so easy - I know the flowers I have taken the pollen from. But can I identify pollen taken from bees to work out what they have been feeding on? There are several useful websites for identifying pollen. The Global Pollen Project is good, but my favourite is the Northumbrian Bees pollen gallery. 

By coincidence, this month's Microscope Club also involved messing around with pollen and as usual, I picked up some useful tips. Size as well as shape is a key feature of identifying pollen grains and the standard is to make sure the pollen is fully hydrated before measuring, thus aqueous media are used. Glycerol Jelly is the standard medium but is a pain to work with, so I'm using Magnacol aqueous mountant. In water alone pollen grains are quite frisky and move around, making photography difficult. The Magnacol mountant contains PVA and is quite viscous, which fixes the grains better. 

This is very much a work in progress but it will be interesting to see what I can find as the season progresses (assuming there are enough hours in the day). 

Where the bee sucks, there suck I:
In a cowslip’s bell I lie;
There I couch when owls do cry.
On the bat’s back I do fly
After summer merrily.
Merrily, merrily shall I live now
Under the blossom that hangs on the bough.

Book Recommendation: Micro ladybirds of Britain and Ireland

One day all field guides will be this good.

In many ways micro ladybirds ("inconspicuous ladybirds") are a perfect group for a field guide. With around 50 ladybird species in Britain, half of these are the familiar spotted ladybirds. The remaining 25 species, the "inconspicuous ladybirds", are the subject of this book. The illustrations are excellent, the descriptions of the identifying features clear and concise and the comparison plates of similar species particularly useful. A microscope is not required to use this guide, all you need is a 10x hand lens, which will reveal most of the structural features of importance.

A real gem of a book and at a bargain price. You'd be daft not to buy it: 

https://www.field-studies-council.org/shop/publications/micro-ladybirds-of-britain-and-ireland/

 

The Entomological Society - keeping the lights on

The Entomological Society, Rembrandt via Gemini AI

I'm troubled by the ongoing demise of traditional wildlife groups, the sort that (used to) meet in a village hall once a month. I observe them gradually blinking out, one by one. I don't have any magic solutions for this (maybe there are none), here I'm just whistling in the dark to console myself and using this as a sketchpad for ideas.

What is keeping local natural history groups alive? Mostly, talks on "I jetted off to an exotic location buring tons of carbon to photograph wildlife". Ironic, isn't it? 

Characteristics of thriving wildlife groups:

• Tend to have an active website or Facebook group, frequently maintained by one or a few individuals. Facebook is probably not the best platform for this, but speaks to the demographic which dominates wildlife groups. Bulletin boards, which might be an obvious alternative, seem to have mostly died, being eaten by Facebook for the elderly, and Discord or WhatsApp groups for the young. 
• Some wildlife groups may have an active website, maintained and driven by an individual who has the time and skills to support this (dangerous, can become fossilized as technology changes, single point of failure). Interestingly I'm not aware of any thriving wildlife group based around an email list or newsletter (which is odd considering the penetration of this technology into the demographic). Maybe I'm missing something?
• Tend to have synchronous face-to-face meetings in addition to online activities. This can be based on geography - local groups, or field meetings, etc, for taxon interest groups.
• And?

But: 

Communities don't live forever, they have lifetimes (particularly since most are maintained by a small number of enthusiasts). Individual members' life circumstances change, so communities evolve (rather than die). This is a tough process for individuals - natural selection - but inevitable. 

So where do we go now? DOBS

• Daylight: Daytime sessions exclude some, but given the demographic, fewer people are active after dark (except for online meetings). 
• Online: works for some, not all. Neither better nor worse than the traditional organizations, but different. 
• Go Big: national societies e.g. BENHS, BAS, etc - not good for carbon footprints.
• Go Small: local face-to-face meetings arranged directly between participants. Accept scheduling problems - everyone is too busy to do everything. Quality of interaction counts, not numbers.
• And?

Please insert your thoughts here: 

Floating frames for macro photography

One of the good things about social media (if you're doing it right) is learning from people who are smarter than you are. A post by Mark Webster on Bluesky put me on to floating frames. Floating frames consist of two layers of transparent flexible film which can be used to trap an object between them and give the illusion that it is floating. They are widely available online (I bought mine from Amazon) in a range of sizes (I bought the 7cm size). Small insects can be trapped within the frame immobilizing them for macro photography. As the film is soft and flexible the insects are unharmed and released after identification. Here is the the result: 

With use the transparent film will mark and the frames will need to be replaced, but so far so good! 

 

 

Kleidocerys privignus

Kleidocerys resedae, the Birch Catkin Bug, is a familiar and very common species of Lygaeid. Two closely related species are more problematic. Kleidocerys ericae was differentiated from K. resedae based on pigmentation and the fact that it feeds on heathers (Erica spp but not Calluna so I'm told). Kleidocerys privignus also has a different pigmentation pattern and feeds on Alder (Alnus). My natural inclination is to be a taxonomic lumper so I'm inclined to disregard the pigmentation differences (intermediate forms occur) and the food plant preferences (which laboratory rearing experiments have shown are not absolute) and regard all three as a single species. My ultimate authority on Hemiptera, Pericart, wasn't sure about these three, and without the benefit of DNA analysis hedged his bets, so no clear answer there. I was able to live with that until recently when I did some DNA analysis which implies that all three are indeed distinct species, see: https://ajcarthropoda.blogspot.com/2025/02/the-kleidocerys-conundrum-resolved.html

Which brings us to the question at the heart of this - what is a species? These days, the answer depends a lot on who you ask, but everyone agrees that it's now a lot more complicated now than when the species concept was developed. I'm afraid I have the old-fashioned opinion (which is bound to upset some) that a species is a group of organisms which are reproductively isolated. There are lots of ways to be reproductively isolated, e.g. pioneers trapped on an island, but it is also possible to be reproductively isolated behaviourally. A good example of this is the wolf spider Pardosa lugubris. This was split into two species based on observations of the male courtship dance (Cryptic species and behavioural isolation in the Pardosa lugubris group (Araneae, Lycosidae), with description of two new species. (2000) Bulletin British Arachnological Society, 11(7), 257-274). Being eaten by the female if she rejects your dance moves is pretty strong selection leading to reproductive isolation. Which brings us to Kleidocerys again. Like many Hemiptera, Kleidocerys communicate by stridulation. In this genus, sound production may not to be associated with mating but occurs when they are disturbed, perhaps as a territorial statement. K. ericae stridulates at a frequency of 16 Hz while K. resedae uses a lower frequency of 8 Hz (Stridulation and its analysis in certain Geocorisae (Hemiptera Heteroptera). (1957) Proceedings of the Zoological Society of London, 129 (3): 351-358). This is equivalent to the Pardosa mating dance and is likely to cause reproductive isolation, which is borne out by the DNA analysis of the two species. I don't know about stridulation frequency in K. privignus but the DNA analysis means that if we accept K. ericae as a distinct species from K. resedae, we have to do the same for K. privignus. 

Recently I sampled 20 Kleidocerys specimens from Alder here in Leicestershire. My overall impression is that they are quite variable in pigmentation, but in my sample, 1 out of 20 specimens has the pigmentation described for Kleidocerys privignus, the others appearing to be variants of the extremely common Kleidocerys resedae. 

The upshot of all of this is that while it's not clear if K. ericae occurs in VC55 (we have limited heather here), I think it's clear that K. privignus does. Now we need boots on the ground to get out there and figure out the field ecology. 

Many thanks to Jim Flanagan for helpful discussions, and for sharing this interesting paper: 

Davranoglou, L.R., Taylor, G.K., & Mortimer, B. (2023) Sexual selection and predation drive the repeated evolution of stridulation in Heteroptera and other arthropods. Biological Reviews, 98(3), 942-981.

 

Bees Knees - Minding The Gap

It's been a good year for bees so far - the weather has suited them. Last month I found an interesting mining bee in my garden. Leicestershire has fairly good bee records, but they are mostly focussed on bumblebees. The solitary bees (and even more so solitary wasps) are a black hole in recording, particularly when it comes to verification of records. Solitary Hymenoptera in general are a vast and growing skills gap in our knowledge. Partly spurred by curiosity at my find and partly by guilt, I bought a copy of the excellent Falk and Lewington field guide and set off on a quest (Falk, S. (2019) Field guide to the bees of Great Britain and Ireland. Bloomsbury Publishing). 

I wasn't expecting it to be easy, which is good because it's not. This is not an area where casual recorders are ever going to make much impact beyond a handful of species. Nevertheless, I'm enjoying the challenge although I wouldn't have got very far with the field guide alone and without the support of the highly knowledgeable online bee communities. Whether I'll be able to make any sort of impact when it comes to the skills gap it's far too early to say. 

 

Entomology Update - April 2025

April has been a busy month for me, but here are my highlights.

In Praise of Mud

Mud - in January we were drowning in it, but now it's in short supply and that's bad for wildlife.

FIT Counts

The FIT Count season runs from 1st April to 30th September. After starting April with cold northeasterly winds I finally managed to get going. 

Video: Hidden Details - The Magic of Macro Photography

An introduction to macro photography - capturing small subjects at a very close range, often revealing details that are not easily seen. This video is aimed at people interested in starting macro photography and those who would like to improve their photos.

Transformation

My favourite wood has been transformed. 

AI is coming of age - as this potentially useful tool demonstrates

You don't have to like AI but you do have to live with it - it's not going away. So while we wait for the singularity, let's make it useful.

Springtails on NBN

Thanks to the hard work of James McCulloch & Duerden Cormack, more than 6,000 springtail records have been imported from iRecord and are now available on the NBN Atlas. 

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