Category: Science

We visited Somerset in the summer of 2019 despite neither of us being fans of cider. We stayed on a beautiful part of the county’s north coast and did a lot of walking and visited a few nature reserves in the hope of seeing bird and insect species we might not commonly see in Cambridge where we live.

The Silver-washed Fritillary, Argynnis paphia, was one of the Lepidoptera I hoped to photograph. The species is widespread over the South West and Ireland (see here) and we saw several on flowers in the gardens of a cafe we visited after a five-mile walk. Spotted them only after I’d taken off my walking boots to cool my feet, so I was painfully tiptoeing over their gravel walkways to get a close-up.

Turns out the butterfly’s range extends all the way up to Cambridge, so we needn’t have gone that far if “ticking” that one species had been the sole aim of the trip. Yoga buddy Celia sent me a photo of paphia she had snapped in Hayley Wood Nature Reserve just west of Cambridge earlier this week.

So, on Friday I drove the 13 or so miles to this Wildlife Trust reserve with the aim of getting some new snaps of the species. I tramped up and down its empty footpaths for two or three hours. I passed one other person, a jogger, the whole time I was walking and then saw a Dad with his two teenage kids when I was at the top of the reserve’s observation tower.

Anyway, I had seen very few birds, various butterflies (Comma, Meadow Brown, Peacock Red Admiral, Ringlet, Skipper, White (Large and Small) and having sat at the top of that tower was packing up my camera kit and readying to head home when I spotted a Hummingbird Hawk-moth flitting about among the fallen branches at the foot of the tower. This is the first one I’ve seen in this country since two of them were feeding on our Red Valerian in our back garden last September. Anyway, camera out, again…moth photographed.

Heading back to the car I took a 90-degree detour up a narrow and somewhat narrow footpath, which is when I spotted the first paphia of the day…and then another. They were too quick for me to raise my camera and get a shot, disappearing as they did into the overgrown foliage. I doubled back, maybe it’s a favoured spot, I thought…and thankfully it was indeed, another appeared, perched on a leaf, happy to be photographed at the requisite three metres of my 600mm zoom. Then another two.

Unless the butterflies had also doubled back, I hazard a guess that I saw five in this spot within the space of twenty minutes. I only ever saw two simultaneously, so it is possible there were actually between two and five.

The silver-washed fritillary butterfly has black spots on deep orange wings, and can be about 50 to 70 millimetres across when wings full open. The males are a little smaller and paler than the females. The name is derived from the character of the underside of the wing which is green with “artistic wash” silver streaks instead of the silver spots seen on other fritillaries. The adults feed on the nectar of bramble, thistles, and knapweeds, all of which were present lining the footpath.

Lots of Blackcaps and Wrens calling in the woods, but didn’t see much avian activity until I got back to the car, Whitethroat and a Red Kite overhead, quite low.

Obviously, it’s not really Part 96vii/d (that’s just one of my perennial jokes). I think it’s probably the thirtieth or so post of moth garden safaris though…these are some of the varied species that made an appearance in the garden last night, drawn to the ultraviolet lure. My garden list is almost at 350 different species, there are some 1800 species in the British Isles overall, so still a long way to go and some species will never been seen in this little corner of England.

Again today, just seemed to be two Brassy Longhorns, Nemophora metallica, dining on the Field Scabious on the Cottenham Lode today. There are dining partners in several of the shots

Thankfully the people who have mowed the upper part of the bank (for some unknown reason) didn’t trim the scabious…

Sciencebase readers who also partake of my Imaging Storm website will know already that the moth season has taken off. Night-flying leps are coming to the ultraviolet lure at a rate of knots now; 120 specimens of 60 different species last night (night of 23rd June 2020, logged on the morning of the 24th, many of them NFY (new for the year) and some even NFM (new for me, or as some moth-ers do ‘ave it, NFG, new for garden).

For those who like the stats there have been 20 species NFM in 2020 so far, most of them in the last week. I have no photographed almost 350 moths mostly in the garden, but one or two on field trips (holidays and camping trips) where the opportunity arose. 2000 specimens logged and many photographed so far in 2020.

Metallica are performing out on The Fens – The Brassy Longhorns, Nemophora metallica, feeding and presumably breeding on the Field Scabious growing on the west-facing bank of one of the local fenland drainage ditches known as the Cottenham Lode.

 

TL:DR – There are numerous green moths, they have evolved to mimic leaves and so evade predators through a simple camouflage mechanism. Green Silver-lines is a lovely example of a green moth.

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Some moth names are just so obvious. This member of the Lepidoptera is mostly green and has silvery lines on its wings, hence Green Silver-lines. It’s scientific binomial is a little more cryptic, Pseudoips prasinana.

This is the largest of the resident Lepidoptera of The British Isles: the Privet Hawk-moth, Sphinx ligustri. As its scientific name suggests, this is one of what are commonly known as Sphinx moths in the US and elsewhere. This species can have a wingspan of up to 120 millimetres when its wings are full extended.

At the other extreme of size scale is the Satin Grass-veneer, Crambus perlella, is one of the smaller of our moths, oh not the smallest by a long chalk. It is by definition a micro moth, but the division between micro and macro moths (such as the Privet Hawk-moth above) isn’t, as one might assume, about size but rather the position of the animal on the evolutionary family tree.

As I understand it, what we might term the oldest species, the more “primitive” moths are grouped as the micros. This perhaps bizarrely includes all of the butterflies as micro moths. The macros are then a second evolutionary wave that came millions of years later. Many micro moths around the world are much bigger than the Privet Hawk-moth and many are larger still than some of the much bigger tropical macro moths.

Large Skipper, Ochlodes sylvanus, in flight. My old Canon 6D full-frame digital SLR would never have locked focus quickly enough to get a shot like this. This was taken from about 3 or 4 metres away with a 600mm zoom on a Canon 7D mkii. f/6.3, 1/1600s, ISO 500. I should’ve used a faster shutter speed to freeze the wings as they flap very quickly in this skippy little butterfly.

The 2/3rds cropped sensor of this camera gives the Sigma lens the equivalent “reach” of a 900mm lens, i.e. nominally 50 percent longer focal length. This is an arbitrary fact really, it’s not optical zoom, it’s equivalent to digital zoom on a pocket camera. The photo is also cropped to a much smaller square. Nevertheless, with a similar number of pixels on the smaller sensor and ignoring edge effects, which are negligible except in extremely tightly cropped images, this is far superior to something the 6D would manage.

For those who wonder what the difference is between butterflies and moths, there is none. According to Lepidopterist David Slade asking what is the difference between butterflies and moths is like asking what is the difference between ladybirds and beetles. The butterflies are simply a sub-group of the so-called micro moths (generally considered to be “less evolved” than the macro moths, with a few exceptions), just as any other sub-group within the Lepidoptera (Noctuidae, Pyralidae, Erebidae, Geometridae` is).

The butterflies as a group of moths, however, do differ from all the others, micro and macro in that they lack a mechanical coupling that hooks forewing to hindwing.