Wednesday, 4 November 2026

Evolution Reading List

 

Evolution Reading List

Darwin and the Barnacle — Rebecca Stott  

The story of Darwin’s eight-year immersion in barnacle research, beginning with an unusual specimen collected in Chile. Stott shows how this seemingly narrow obsession helped him investigate variation, build his scientific reputation, and prepare to present his theory of evolution—all amid family life, illness, and personal loss. 

Darwin’s Ghosts — Rebecca Stott  

A history of the thinkers who explored the possibility of evolutionary change before Darwin. Through interconnected portraits of figures including Aristotle, Diderot, and Lamarck, Stott shows how evolutionary ideas developed over centuries, often in the face of religious and political opposition, rather than appearing through one person’s isolated breakthrough. 

Radical by Nature — James T. Costa  

A biography of Alfred Russel Wallace, who independently discovered natural selection and became Darwin’s friend and supporter. It follows his rise from modest beginnings through adventurous collecting expeditions, while exploring both his scientific achievements and his unconventional commitments to socialism, spiritualism, women’s rights, and social reform. 

 


Zooming in on the Hangers On

Drosophila immigrans & Drosophila hydei with mites

My garden compost bin has been producing clouds of Drosophila. Before it cooled off I had to stand back when I opened the lid to avoid being covered in flies. Over the weekend I took a closer look. They turned out to be a mixture of two species, Drosophila immigrans and Drosophila hydei, both cosmopolitan tramp species. 

Looking closer, most of the D. hydei were carrying a good load of mites. The good folks of the Facebook Soil Biodiversity UK group were able to identify these for me as Macrocheles spp. These are predatory mites which feed on nematodes, small worms, fly eggs and larvae and other tiny arthropods. They are strongly associated with ephemeral, nutrient-rich substrates such as leaf litter, decaying plant matter, animal dung, carrion, and animal or insect nests. A common behaviour in this group is phoresy - the mites attach to mobile carriers such as flies to travel from one temporary food source to another. Adult females are the usual dispersal stage, and phoresy is typically non-feeding transport rather than parasitism. Their reliance on transient resources makes rapid colonization and dispersal central to their life history: when a resource is exhausted, phoresy lets populations reach the next suitable habitat. 

Macrocheles spp mite

Looking closer still and the mites were carrying a load of sac-like objects. They seem to be nematode dauer larvae, hitching rides from one compost heap to another. A dauer larva (from the German dauer, meaning "endurance" or "persistence") is a stress-resistant non-feeding third-larval stage that some nematodes enter when environmental conditions are unfavorable. Instead of progressing to adulthood, the worm halts development at this specialized stage. Dauer larvae do not feed and slow down their metabolism dramatically. They can survive for several months (up to four times longer than a normal lifespan), enduring harsh chemicals, desiccation, and extreme temperatures. Dauers actively seek out new environments; once they encounter favorable conditions (such as fresh food or a host), they exit the stasis, moult and resume normal reproductive development. The anti-slug nematodes you can buy are actually dauer larvae and another example was a dauer larva frozen in Siberian permafrost 46,000 years ago, when Neanderthals still walked the Earth, which was revived successfully (A novel nematode species from the Siberian permafrost shares adaptive mechanisms for cryptobiotic survival with C. elegans dauer larva. (2023) PLoS Genet 19(7): e1010798 https://doi.org/10.1371/journal.pgen.1010798).

Nematode dauer larvae

Bear in mind that the mites eat ... nematodes amongst other things, so you could regard this as livestock farming - the mites pack dauer larva before going off on their Drosophila package tour, thus they have a food source when they arrive. And all  this is without looking for parasitic wasps utilizing the flies, mites and possibly even nematodes in my compost heap. Who knew my discarded banana skins were so interesting?

 

 

Sunday, 1 November 2026

Entomology Update - October 2026

As we careen towards the solstice, welcome rain continues but the impact of the summer lingers - few mature insects around and unknown prospects for next year. 


The New Forest Authority is doing a first rate job of managing an ancient landscape under intense tourist pressure - hats off to them. 

A. Cann & S. Timms. Psallus (Heteroptera: Miridae) on Turkey Oak in Britain. (2026) British Journal of Entomology and Natural History Volume 39, Part 3, p146-7.

I've recently become aware of the existence of Pentax Papilio binoculars, a potentially very useful piece of kit.

Every once in a while I have a crazy urge to deep dive into a new neglected taxon. Sometimes I resist.

Notable Finds

Dendrocerus aphidum, 1st record for VC55

News from Elsewhere

You don't know what you got til it's gone. 



Common Carder Bumblebee, Bombus pascuorum



Monday, 26 October 2026

Pergamasus

Pergamasus spp

 Every once in a while I have a crazy urge to deep dive into a new neglected taxon. Sometimes I resist. 

Back in lockdown I listened to an excellent online talk on mites, and since I regularly get them in vacuum samples, I was tempted, but managed to resist. Over the stormy weekend I was clearing a backlog of samples from the past year and in one came across this chunky red-ish mite. Given the weather, I took photos and posted them on the excellent Facebook Soil Biodiversity UK group asking for help. One of the experts there was able to identify it as a male Pergamasus spp. (Family Parasitidae). I'm very grateful, but I'm still not planning on working on mites (or Thrips, which are easier) very often. 

Pergamasus (suborder Mesostigmata, family Parasitidae) is a species-rich genus of soil-dwelling predatory mites. They are key apex micro-predators within the soil food web, primarily distributed across the Holarctic region. Relatively large for soil mites, usually ranging from 0.8-1.5 mm in length. They are typically well-sclerotized with a characteristic yellowish-brown to dark reddish-brown chitinous body. Broadly oval, somewhat dorsoventrally flattened, with robust legs adapted for rapid movement and grasping prey. Adults possess a large, rigid dorsal shield (single, continuous plate covering the back) or a deeply divided schizodorsal shield depending on the species. Females possess a distinct, triangular or acuminate genital shield (epigynium) flanked by metasternal shields. Male leg II is heavily modified into a grasping organ with pronounced skeletal spurs and apophyses used during mating. The chelicerae feature a modified spermatotreme for sperm transfer. Found in soil & litter layers, both nymphs and adults are fast-moving, voracious generalist predators feeding on a wide variety of soil micro-invertebrates. They use their powerful, chelate chelicerae to puncture prey and suck out bodily fluids.


Bhattacharyya, S.K. (1963) A revision of the British mites of the genus Pergamasus Berlese s. lat. (Acari: Mesostigmata). Trustees of the British Museum (Natural History).

 



Wednesday, 21 October 2026

Bugnoculars

Pentax Papilio binoculars

I've recently become aware of the existence of Pentax Papilio binoculars. Most binoculars struggle at close distances, causing double vision or misalignment between the left and right eyes. These binoculars solve this with a mechanism that physically shifts the front lenses as you focus closer, ensuring a comfortable view. For long-range viewing, the lenses automatically return to their normal position. They can focus on subjects just 50cm away, making them useful for examining plants, insects, etc, and very useful for anyone with limited mobility who is unable to bend or kneel. They come in two magnifications: the 6.5x version has a wider field of view and steadier handheld viewing, useful for tracking moving subjects; the 8.5x version provides more magnification for studying distant details.

I've had good reports from people who use these, although on rreflection I wondering if a used compact zoom camera such as a Panasonic Lumix DC-TZ or Sony Cybershot might be a better alternative which allows image capture too. 



Tuesday, 13 October 2026

Psallus on Turkey Oak in Britain

A. Cann & S. Timms. Psallus (Heteroptera: Miridae) on Turkey Oak in Britain. (2026) British Journal of Entomology and Natural History Volume 39, Part 3, p146-7. 

Psallus on Turkey Oak in Britain
click for larger image






Monday, 12 October 2026

What's Old is New

The New Forest

I've just spent a weekend in the New Forest, a place I've always wanted to see but have never visited before.  It was called the New Forest a thousand years ago (when it was already 11,000 years old), to confuse American tourists.  And it's stunning, so rich in biodiversity.  It has a medieval feel to it, a mosaic of wood pasture, grazed by cattle and horses, and at this time of the year, herds of pigs turned out into the forest to fatten on acorns (pannage). Almost inevitably, wherever I visit I'm disappointed at the land management practices from a conservation standpoint, but I can't say that about the New Forest.  Dead wood is everywhere, pretty much left where it falls.  The New Forest Authority is doing a first rate job of managing an ancient landscape under intense tourist pressure - hats off to them.  If only more areas were managed with the same care. 




Saturday, 3 October 2026

Entomology Update - September 2026

A great many wasps this month.

I am absolutely rubbish at rearing insects but I'm trying to be a good Hymenopterist by rearing parasitoids out from their hosts. In theory, this should make my life easier by making the emerging insects easier to identify - but things often don't go to plan.

Notable Finds

Spaniopus dissimilis, 1st record for VC55
Hemiptarsenus fulvicollis, 1st record for VC55
Sycophila mellea, 1st record for VC55
Coelopisthia extenta, 1st record for VC55
Phygadeuon trichops, 1st record for VC55

News from Elsewhere

Invertebrates in big trouble
A new report by the JNCC highlights over three-quarters of all endemic invertebrates in UK Overseas Territories are classified as threatened, meaning that they are at a high risk of extinction. Across all endemic plant and animal types, the three species groups with the highest proportion of threatened species were invertebrates, with almost all crustaceans and nearly 9/10 arachnids and insects considered threatened.

A Robin's Pincushion (Bedeguar Gall) isn't just a home for the wasp larvae that caused the gall to form, it's a thriving miniature ecosystem. 
 

The Little Things That Run the World


Tuesday, 8 September 2026

Squatters

Bedeguar Gall inquline

I am absolutely rubbish at rearing insects but I'm trying to be a good Hymenopterist by rearing parasitoids out from their hosts.  In theory, this should make my life easier by making the emerging insects easier to identify - but things often don't go to plan.  I collected a Bedeguar Gall (Robin's Pincushion), caused by the wasp Diplolepis rosae, on 24.07.2026.  Miraculously, it survived my tender care (only slightly moldy) until on 05.09.2026 a wasp emerged.  But it wasn't Diplolepis rosae, a brownish wasp, but instead a bright metallic green wasp with a long ovipositor.  The obvious candidate was Torymus bedeguaris, but there are 19 confirmed inquilines (from the Latin inquilinus, "tenant" or "lodger"), of Diplolepis rosae, and this squatter had an ovipositor only slightly longer than its body (that of Torymus bedeguaris is typically twice as long as the body).  Torymus species are very difficult to identify, but with some help I was able to confirm that this is Torymus rubi.  This species is a polyphagous parasitoid of Dasineura acrophila; Diastrophus rubi; Diplolepis mayri, nervosa, rosae, spinosissimae; Lasioptera rubi; Liposthenes glechomae; Stereonychus fraxini, on host plants including Fraxinus, Pteridium aquilinum (Bracken), Rubus, and Rosa. 

There's a lot going on inside Robin's Pincushions and I'm hanging on to this one for now to see if anything else emerges. 

Torymus rubi female



Askew, R.R., Plantard, O., Gomez, J.F., Nieves, M.H., & Nieves-Aldrey, J.L. (2006) Catalogue of parasitoids and inquilines in galls of Aylacini, Diplolepidini and Pediaspidini (Hym., Cynipidae) in the West Palaearctic. Zootaxa, 1301(1), 1-60.

Graham MWR de Vere & Gijswijt MJ (1998) Revision of the european species of Torymus Dalman (s.lat.) (Hymenoptera: Torymidae). Zoologische Verhandelingen, Leiden 317: 1-202.

Leicestershire Entomological Society Newsletter 37, September 2007: https://www.naturespot.org/sites/default/files/downloads/Newsletter037.pdf