Category: Biology

Orange Swift (Triodia sylvina) – A first for the garden 13th August 2018 in three weeks or so of moth-ing with Rob’s homemade actinic Robinson trap.

Given how brightly coloured this specimen is compared to other photos of the species on UKMoths, for instance, I am assuming it is a male. The males are also smaller than the females, such sexual dimorphism does not seem to be a common trait in the moth world, although it does occur (viz some females are wingless and the Emperor Moth females are like a desaturated version of the male). The species is a member of the Hepialidae of which there are, it seems, only five members in the UK: Orange Swift (Triodia sylvina), Common Swift (Korscheltellus lupulina), Map-winged Swift (Korscheltellus fusconebulosa), Gold Swift (Phymatopus hecta), and the Ghost Moth (Hepialus humuli). Update: 11 May 2019, first Common Swift to the trap. Not seen any of these others yet.

The Orange Swift flies later in the year than the other Swifts, July-September (in the British Isles), so spotting one in the middle of August is about right, although UKMoths explains that it inhabits waste ground, moorland, and other wild places. Doesn’t say much for my gardening skills.

The larvae (caterpillars) feed on the roots of bracken, dandelion, dock, hop, and viper’s bugloss. It overwinters twice as a larva.

Night of 10th August 2018 saw a serious drop in temperature. We’ve been enjoying/sweltering in relatively balmy upper teens and into the 20s at night since May, but last night it dropped below 10 degrees Celsius in many places. The moth-ers are almost all reporting very few specimens in their traps. Personally, I had one Spectacle, a solitary Silver Y, a single Willow Beauty in the trap, and another on the white sheet hanging next to the light, and a few LBJs (Little Brown Jobs).

So here’s one of the highlights from a couple of weeks ago, a Canary-shouldered (Ennomos alniaria). It is a geometer moth (Geometridae) found across Europe. Geometers get their name from the behaviour of their larvae or caterpillars, which are whimsically also known as inchworms, their method of locomotion being reminiscent of someone measuring the earth. They’re also called loopers, for the “loop” the caterpillars form as they do their measuring.

In the UK, the adults breed in a single generation from July to September. They’re commonly found in woodland and gardens and the larvae eat the leaves of various deciduous trees. Indeed, the second part of its scientific binomial, the alniaria refers to the alder tree. The Ennominae are the largest sub-family of geometer moths, with some 9700 known species in 1100 genera.

TL:DR – Can moths fly in the rain? Some definitely can. I suspect many would prefer not to.

9th August 2018 was the first proper day of rain in VC29 (Vice county Cambridgeshire) since May, there were a few spots and a bit of storminess earlier in the month, but a proper drizzle turned to a downpour yesterday. I was not holding out much hope of a night of mothing. So, I asked the members of the Moths UK Flying Tonight Facebook group thought about “lighting up” on a wet night.

First response was not a positive one: “Don’t bother if it’s raining, nothing much will be flying.” But, subsequent responders said that they “had some great moths on rainy nights!” And suggested it might be worth lighting up, after all.

“Some of my best catches have been on wet nights especially if it is drizzly and not too heavy…I have trapped on many a rainy night and had some of my best catches on them, I don’t usually bother if its heavy rain but drizzle to light rain is still worth it as long as not too windy I find…Moths don’t mind the rain. I’ve had some of my best nights during drizzle, even steady rain. As long as you waterproof everything you will be fine…It’s the wind, not the rain, that I find is dire for mothing..cold wet and windy being fatal.”

So after all that I let the moths make their choice and was rewarded with a few: Broad-bordered Yellow Underwing, Mother of Pearl, 3-4 Setaceous Hebrew Characters, a Turnip, 1 a Silver Y, and 4-5 unidentified micro moths. That was it. It was worth a try but I think the rain got heavier in the night and the wind picked up. I reckon I will set up on the garden table next time if it’s raining and put some white sheeting under our patio umbrella…

Having scored high on the first morning with the trap in its owner Rob’s garden – Poplar Hawk Moth, Blood-vein, Buff Ermine, Burnished Brass – and then the next morning in our garden – Ruby Tiger, Canary-shouldered Thorn, Jersey Tiger – I had high hopes for the last couple of weeks.

Indeed, the moth-ing has been rewarding so startling and stunning creatures have turned up – Setaceous Hebrew Character, The Spectacle, Pale Prominent, Willow Beauty, Mother of Pearl, Angle Shades etc etc…about 50 different species I have identified with some assistance from Brian Stone, Rob Ellis, Leonard Cooper, and others, as well as Ian Kimber’s excellent and comprehensive UK Moths site.

However, this morning’s haul looked less hopeful, especially when opening the trap at least three or four large-ish moths (Yellow Underwing and another not identified) escaped into the shrubbery in a flash (of yellow under their wings). Extracting the cardboard egg trays gingerly nevertheless and observing some of the familiar species  Brimstone, Silver Y, Turnip, Least Carpet – I turned over the last of the four and there was the beauty of this blog post title – Elephant Hawk-moth – with its olive-green and, almost-lurid pink colouration.

The Elephant sat a spell for a few closeups and then tentatively clambered about a proffered twig and began its quivering to warm up in the early morning sun. I could see it quivering and feel the vibration through the twig. It then hopped on to a leaf of our apple tree for a few final poses before disembarking and heading for the ivy-clad fence and upwards and onwards towards our neighbour’s garden and freedom in their hedge. To fly another day…or, rather, night.

Incidentally, its common name comes from the fact its larvae (caterpillars) look like an elephant’s trunk. Intriguingly, and as you might expect for such a colourful moth, the Elephant Hawk-moth has very sensitive eyes and was one of the first animals in which nocturnal colour vision was reported by science. Chemists have used gas chromatography and mass spectrometry to identify the female sex pheromones as  (11E)-11-hexadecenal and (10E,12E)-10,12-hexadecadienal [(E,E)-bombykal] – https://link.springer.com/article/10.1007%2FBF01920249.

The Elephant Hawk-moth is not uncommon in the UK, especially across the lowlands of southern England. Usually a night-flyer May to July, so quite lucky to catch one more than a week into August as their season tails off. The weather had changed somewhat yesterday from the persistent heat and dry windless days and nights to a smattering of raindrops and a bit of wind and a modest decline in temperature.

I think the name of this moth, Angle Shades, would make a great name for a progressive rock band, their first album would, of course, be Phlogophora meticulosa. The species gets its common name from its characteristic forewing markings. The base colour is buff, brown towards the edge of the wing most distant from the body, the termen.

Angle Shades is marked with a bold V-shaped pink and green marking. Overall, the colouration and angular markings create a disruptive camouflage. To my eye seeing this moth for the first time in the trap on the morning of 2018-08-06 it looked very much like a small autumnal leaf, at least it did until I donned my reading glasses.

Angle Shades is a member of the Noctuidae, also known as the owlet moths. It is found across Europe all the way to the Ural Mountains, but is also seen in The Azores, Algeria, and in Asia Minor, Armenia, and Syria. It is a strongly migratory.

And, speaking of which my friend Bea Perks once wrote about the Silver Y (Autographa gamma) and the fact that to be able to migrate, this moth, and presumably many others, have to fly at an altitude of about 1 kilometre otherwise they don’t survive long enough to reach their destinations.

This is the Silver Y:

It sounds like a woodworking term, Scalloped Oak, but it is in fact a moth: Crocallis elinguaria. Here is one specimen that was in the trap this morning, it was a dewy night, there was very little else in the trap, a few Turnips, a Setaceous Hebrew Character, a Yellow Underwing and various micro moths. I believe this is a female, it is paler than the other C. elinguaria I’ve seen in the trap over the last week. They vary a lot in colouration and shading, however. The adults are night-flyers and attracted to light.

The Scalloped Oak, so-named for the brown band across its wings that looks like a piece of oak that has been, well, scalloped. Its scientific name is a little more intriguing. The Crocalis is from Latin and alludes to yellow colouration. elinguaria means “without a tongue”. These moths do not feed, all their feeding was done when they were at the larval stage and the adults are simply sex machines. We could perhaps call it the the yellow, tongueless, sex machine moth.

It was dark outside, but very few moths seemed to be around last night (31 July 2018), a Brimstone, a few micro-moths, a couple of Underwings and a Setaceous Hebrew Character. Other moth followers are reporting the same this morning, almost nothing in their traps. Given that this time last week we had a bumper haul of all sorts in the Rob Ellis trap, perhaps autumn is upon us.

Anyway, this Riband Wave (Idaea aversata f.remutata) alighted on one of the trap’s flight baffles not long after dark. I illuminated it from behind with a phone torch and snapped it from the other side with camera on a tripod…looks like a soft tissue X-ray or something…ish.

I am gradually adding moth species to my lepidoptera gallery on Imaging Storm. There are some 2600 different species in the UK alone (160000 worldwide). I’ve photographed and released about 50 so far since enlisting the help of a light trap.

As of 21 Sep 2018, less than two months in, I had doubled that number.

Still hoping for more Hawk-moths (only seen a Poplar and an Elephant in Cottenham so far, and a pair of Privet last year). The Jersey Tiger is the most unusual and unlikely, I’ve seen, although it never entered the trap just hung around in the dark and ultimately rested on the outside of the box. There is some hint that this native of the Channel Islands has spread north but some enthusiasts are propagating them in more far-flung places; they shouldn’t be doing that.

The slowly increasing list of species I have photographed and identified can be found at the foot of my Lepidoptera – Moths and Butterflies page on Imaging Storm. I reached 100+ species in my first two months of mothing. A year after I started I had logged more than 250 species, still just about 10 percent of all the species native to the British Isles!