35 years in science communication
Non-lepidopteral invertebrates
Another Sexton (Burying) Beetle. Thought he needed some macabre riffage to go with his reputation. These creatures drag carcasses underground and lay their eggs within, they also create offensive odour chemicals that mask the smell of death and hide the body from flies and carrion eaters that might interfere with their offspring.
The creature here is Nicrophorus investigator. As far as I can tell it has no common, vernacular, name specific to the species.
It doesn’t seem like five minutes that I was itching to get started photographing the summer migrant bird species. But, it was April that I saw my first Swallow of 2019, House Martins, had been around a few days at that point, and the Swifts came quite a bit later.
I went looking for the local Turtle Doves today, which were still turring last weekend somewhere in the trees along the recently opened bridleway between Fen Bridge Farm and the Les King Wood, in Cottenham, VC29. I didn’t hear nor see them this time. Maybe they’ve already started their journey back to southern Africa, the Cuckoos are long gone, after all, although Reed Warblers are still chattering in the Balancing Pond and along Cottenham Lode.
The Swallows on the barn at Broad Lane seem to be gathering together on the overhead wires, lots of youngsters perhaps wondering why. There were about fifty on one wire and a dozen or so on the barn roof. Will they soon be gone? It’s only mid-July and the Painted Ladies forecast a hot, dry summer to come and abundance of their thistle-eating caterpillars (#AllotmentLife). Indeed, the Swallows were still here at the end of August 2018, but it was an exceptionally hot and dry summer that seemed to start in May and carry on through to September with little respite. Who knows? When they’re gone, they’re gone.
I mentioned the so-called June Gap in butterfly activity between Spring and Summer. It’s a bit of #DeceivedWisdom really, there is such huge overlap between species we usually consider to be Spring species and those of the height of Summer that generally emerge in July. Today, I saw lots of Skippers (Large and Small), Whites, (Small and Large) Small Tortoiseshell (no Large), Painted Lady, Peacock, Meadow Brown, Small Heath, Gatekeeper, and new to my photo gallery Marbled White (Melanargia galathea, Linnaeus, 1758). UPDATE: June 2022 – I’ve seen a lot of Marbled Whites in various places since I first ticked the species and photographed it for Sciencebase, even added it to the garden list in June 2022.
It’s been a while since I mentioned #PondLife. There doesn’t seem to have been any repercussions of last week’s tapwater overkill, overspill. The water is still lovely and clear, the snails seem to be thriving and today I saw a pair of Ruddy Darter dragonflies mating on the wing over and around the water as well as at least one Common Blue damselfly (again). It is becoming a little bit of what I hoped for.
Whereas most of the familiar bees are black and yellow stripey creatures sometimes with a white or russet tail, the Ashy Miner Bee (Andrena cineraria) is black and white with a bit of blue…like a Magpie (hence my blog post title, The Magpies being the nickname of The Toon, Newcastle United Football Club, NUFC). Its name made me think ashy, sooty, pits and miners, obviously; once so common an association with the city to which you need not take coals.
This is a solitary bee, but the females will often make their nests in aggregates along grassy footpaths and short turf. Hence another football connection. I spotted this one on the raised footpath along the water at Earith in Cambridgeshire. Look down as you’re walking and you might spot them from March to June.
UPDATE: 30 July 2019 – Another Sexton Beetle turned up this one doesn’t seem to have a vernacular name, it’s simply known as Necrophorus investigator.
ETYMOLOGY: A sexton was once a member of staff with responsibility for a church’s sacred objects and burying the dead. The word comes from the Old French segrestien, ultimately from Latin sacrista, from sacer, meaning sacred.
UPDATE: Sexton beetles often have mite passengers that eat fly eggs and maggots that are on the carrion the beetle buries. I asked about these and whether or not there is a parasitic mite too on the Moth Trap Intruders UK Facebook group, Malcolm Storey had this to say:
“The usual name given for the mite is Parasitus coleoptratorum which misleads people into thinking they’re parasitic (which people presumably thought when the name was proposed). This stage of the mite is the deutonymph. Apparently they’re “paraphages”. It’s the same small number of mite species on various dung and ground beetles. P. coleoptratorum is probably the commonest of the group. More info: Hyatt, K.H. 1980 Mites of the subfamily Parasitinae (Mesostigmata: Parasitidae) in the British Isles. Bull. Br. Mus. nat. Hist. (Zool.) 38(5): 237-378.”
I’ve mentioned burying beetles before. They’re a type of beetle it’s not a morbid hobby, by the way! These insects drag dead rodents and other animals underground, lay their eggs in them and the larvae as they hatch have a ready-meal to die for! The beetle also produces horrendously smelly sulfur compounds to mask the smell of death, you can think of it as a kind of flatulent Neutradol…
Anyway, in my moth trap morning of 20th March 2019, a specimen of the UK’s only all-black burying beetle, Nicrophorus humator, all-black carapace, that is, ignore the orange clubs on its death-seeking antennae. First Sexton Beetle of the year. This one had several pale-orange arachnid passengers, mites, I believe. Not sure whether they’re parasitic or synergistic.
Even through the scorcher of a summer we just had, nobody was scraping moths and flies from their windscreens and headlights were they? Nobody has done that for a few years now…I know several friends have been wondering why that is…are insects simply avoiding the roads? No, of course, not. What’s happening is that insects are dying out, unfortunately.
The New York Times has finally caught up
Cross, or European Garden, Spider (Araneus diadematus), also known as the Crowned Orb Weaver, Diadem, Orangie, and also the Pumpkin Spider, so perhaps I should’ve held off posting this until Halloween. There is, however, another spider that has the vernacular name Pumpkin Spider.
This is a female specimen. The legs of orb-weaver spiders are specialized for spinning orb webs (although this one had spun a flat web across a small windowpane). The spider constructs its web and then hangs head down in the centre or in nearby foliage, with one claw hooked to a signal line connected to the web waiting for a disturbance as prey enters the web. The spider bites its prey and quickly envelops it in silk. Some enzymes paralyse the prey and preclude the prey biting or stinging the spider. Other enzymes begin the liquefaction (digestion) of the prey’s innards ready for consumption.
Just for the record, this is one of those spiders that cannibalises the male after mating.
I asked arachnid expert Dr Richard Pearce (@DrRichJP) about the fact that spiders seem to have extra pairs of eyes and wondering why other creatures did not follow this evolutionary route. This is what he had to say:
Spider eyes are not necessarily comparable to our own. Many spiders have poor vision. Those with good vision tend to have two primary eyes to give binocular vision (e.g. jumpers - Salticidae; wolf spiders - Lycosidae). The other eyes do not form images in the same way.
Spider photo now in my Invertebrates gallery (non-lepidoptera)
I’m not entirely sure why anyone would want to exclude spiders from their home, my preference would be to have a flyeater in each corner of the room to eat the flies. Flies spread disease. Spiders modulate diptera activity.
Anyway, every autumn, the deceived wisdom that putting conkers, the seed of the horse chestnut tree,  Aesculus hippocastanum, around your home will scare the spiders away comes up. It’s evergreen content for columnists. But, it is a myth, it has been debunked several times over the years.
More about conkers coming soon in my Materials Today column.
I headed to the garden with my SLR camera and a 90mm 1:1 macro lens to snap what insects I could find while it was sunny. In the end, I finally got around to pruning our wisteria, cutting back the grapevines and the bladder senna plants and the overhanging bramble from our rearward neighbour. I left the overgrowing ivy to bloom for the autumnal insects, including the moths, butterflies, and hornets.
Two hours later, I had no insect photos until I spotted a shieldbug on a leaf in the leaf litter. Picked up on and let him run around our old teak garden table. I’d plucked a few grapes from the vines so plonked one of those in front of him for his close-ups. Needless to say, he didn’t sit still for long and with the short depth of field you get with a macro lens like this it was hard to get a sharp shot on his eyes. Of course, you can use focus stacking to get a greater DoF, but that’s hard with a moving subject like a living insect.
I couldn’t find an exact match for this species and settled on it being a Birch Shieldbug. However, Vicky Gilson on the Bug of the Day Facebook group suggested that it was a Gorse Shieldbug (Piezodorus lituratus). She explained that it is “similar to the Birch but more robust and has a yellow edge to its connexivum. It’s in its late summer/autumn colouration, earlier in the season they are more green.”
That “piezo” prefix in its scientific binomial is intriguing…you can read more about it in my latest column in the Materials Today magazine.
A Burying Beetle turned up in the moth trap during the summer. At first, I could hear its beating wings, could see its black and yellow warning colours and assumed it was some kind of hornet until it landed and I got a proper look at it with its large club-like antennae.
These beetles are attracted to dead vertebrates, birds and rodents, by the volatile and very smelly organosulfur compounds produced by a carcass some time after death. If you’ve ever done any sulfur chemistry you know how unattractive you become after working with such compounds in the lab.
The beetle drags its carcass underground, encases it and sprays it with oral and anal secretions to mask the smell of death to preclude other scavengers finding the stash. The body becomes a food source for the beetle’s larvae once they hatch from the eggs the beetle lays on it.
Unusually among insects, the male and female parents take care of their brood, they even work in communities to bury and protect a large carcass. One amateur naturalist friend of mine says he has seen one such beetle dragging a dead Dunnock underground.
Everyone interested in such insects warns you not to handle them as they smell foul and the smell transfers to your skin. Apparently, it takes longer to get the stink off your fingers than it does for a wasp sting to subside! Although I wonder whether the vinegar trick for denaturing skunk spray and fox poo odours might work (bathing in tomato ketchup).
It seems that Burying Beetles secrete a chemical brew through their anus from rectal glands. This spray consists of aliphatic acids and terpene alcohols that smell foul. Among the various molecules are methyl or ethyl esters of 4-methylheptanoic acid and 4-methyloctanoic acid which seem to be male pheromones to attract females.
Some comments on the Moth Trap Intruders Facebook Group suggest that not all specimens stink but that if you do wish to examine them it is best to collect them into a glass, rather than a plastic, pot to preclude the smell being absorbed into the plastic from which it will slowly emanate for months to come.
What a wonderful world…