Category: Biology

This year’s crop of the rather rare Black Hairstreak began emerging at Brampton Wood on 29th May. I didn’t get a chance to visit the site until the 5th June. Intermittent sun meant they butterflies would appear, flit about a bit, and then disappear when the clouds moved across the sun again. There are lots on this site and several other woodlands that dot the landscape between Huntingdonshire and Oxfordshire.

The species is on the wing for a couple of weeks at this time of year mating in and around the old Blackthorn bushes in these woodlands, with that plant being the larval food plant. Unfortunately, unlike some other species, the Black Hairstreak is not a colonialist and it is common that the adults will fly no more than a few metres from the site where they first emerged from their pupae.

A couple of years ago, the transect count for the site was 2000 or so Black Hairstreak. Given the expanse of this woodland, it’s possible that that there were tens of thousands, if not hundreds of thousands, of adult butterflies on the site that summer. It’s nationally rare, and like I say, there are very few places where you will see them, but if you know the right spot…

Incidentally, had a chat with Alice from GreenWings and Steve from Butterfly Conservation. He pointed out a Lackey Moth larva on a tree as we walked from the first BH site to the second site.

I had reason to be in the vicinity of Trumpington Meadows today and although the wildflowers are coming on, very little is in bloom relative to what we see there at the summer peak. There was some Red Campion, Bladder Campion, some Common Vetch, Oxeye Daisy, Red Clover, a tiny bit of early Field Scabious and a few other bits and bobs. I didn’t have high hopes for seeing an early Marbled White or the Small Blues which enjoy the Kidney Vetch there. And, indeed, there were no Marbled Whites on show, but there was a mating pair of Small Blue!

There were numerous Brimstone, Orange Tip, and Peacock, and we had a solitary sighting of Red Admiral. There was a lone Holly Blue at the car park and just one Common Blue (first of the year for me) on the area close to Byron’s Pool. A single Silver Y moth put in an appearance too and a single Green-veined White.

It was over the M11 foot and cycle bridge where there are often more Small Blue in the flying season that we saw half a dozen or so Small Heath (first ones of the year) and then caught sight of the in copulo pair of Small Blue. Dancing among them numerous Grass Rivulet moths, which I’d first seen here in 2022.

It’s been an odd year so far for us moth-ers. There was an odd burst of numbers and diversity back in mid-March but that was followed by some very lean lighting-ups in April when it was generally cold and wet forever. It was only on the 8th May that there was a sudden up-tick. We had warmer evenings and on the night of 12th May, I recorded 36 moths of 25 species. 14 of those were new for the year (NFY) and one of them, Grey Pine Carpet, was new for my garden (NFM).

Next session, wasn’t quite as rich, but there were still seven species NFY, including a couple of Pale Tussock, a Maiden’s Blush, Pebble Hook-tip, The Spectacle, and a White Point. Moth names are just as diverse as the moths themselves.

So, as of 13th May, that’s 84 lighting-up sessions mainly with a 15W Wemlite UV fluorescent tube on a Robinson trap. The next few weeks will hopefully see diversity and numbers rising still further.

I’ve written about the industrial evolution of the Peppered Moth on numerous occasions. It’s held up as an example of evolution in action. Here’s the non-melanic, “clean air” form that turned up on the night of 14th May.

The Silver Y is a migrant species turning up in their thousands some years if conditions are right. It is found all over the UK, but seen most commonly, and obviously, at coastal watch points. Its name comes from the silvery Y shaped marking on its wings. The scientific name is Autographa gamma, which suggests that the marking might also be the third letter of the Greek alphabet, gamma. Often to be seen nectaring on wildflowers and garden flowers during the day, at dusk, and at night.

I usually see well over 300 species in the garden over the course of the year and a few dozen of those are NFM (see definition above). I’ve been mothing since late July 2018 and at last count garden “list” stands at well over 500 species.

An update at this point in the year when it seems to be turning seemed timely.

Footnote

All moths are released unharmed back into the wild well away from the trap after logging and any photography I do. All my records are sent annually to the County Moth Recorder for logging on the county and national databases so adding to our understanding of distribution of different species at the local and national level. Such scientific information can help inform those involved in conservation, agriculture, development, and other activities on which the presence or absence of moths has an impact.

This tiny little creature is the Diamond-back Moth, Plutella xylostella. It’s just a few millimetres long, so snapped with a 30mm extension tube on a Tamron 90mm 1:1 macro lens on a Canon R7 to get as close as possible.

The image was focus stacked, in camera, to improve depth of field and then denoised and sharpened a little with Topaz Sharpen AI. There is a new Topaz product out now that replaces the original Sharpen and Denoise modules. If they send me it to review, I’ll give you the low-down, but it looks good from the demos I’ve seen. Final tweaks to levels and contrast, cropping, and logo done in PaintShopPro, which is a cheap and cheerful substitute for the more well known PhotoShop.

The species is a high-flying, long-distance migrant, that probably originated in Europe, specifically the Mediterranean, or possibly South Africa, it’s present the world over now.

It’s sometimes known as the Cabbage Moth, although not to be confused with another species with that vernacular name. It does eat brassicas. Farmers who plant wintercress on the margins of the brassica fields will generally find that the female of the species will be more attracted to the wintercress than the cabbages etc.

Unfortunately for the moth, while watercress is attractive it is inedible for the larvae that hatch and they die. This biological answer avoids pesticide use and given that the species has evolved resistance to pesticides seems like a good way forward for protecting crops.

Also, new for the year (NFY) in our garden last couple of trapping nights: Swallow Prominent, Ruby Tiger, Waved Umber, Common Pug, Dagger (Grey or Dark no way to know without genital dissection).