Description


A diary of my mothing activity covering highlights and photos from my moth trapping activities. Mainly Norfolk (UK), occasionally beyond. I may mention other wildlife sightings here, especially insects, but for birds see my birding diary.

Friday 10 June 2016

Tens of thousands of moths

On Saturday morning I was up at Titchwell birding and swimming in Diamond-back Moths Plutella xylostella.  OK, perhaps that's an exaggeration, but there really were a lot of them.  They were everywhere, but some places were thick with them - you could see maybe 50-100 in some small patches of vegetation with more appearing if the vegetation was disturbed.  I put down 1000 in my records but that really was a very conservative estimate - just of the moths I'd seen.  I couldn't possibly guess how many were actually there.  Tens of thousands obviously, hundreds of thousands probably, millions mabye?  I wouldn't be surprised.

Not much else of lepidopteran note - a Common Nettle-tap Anthophila fabriciana and 2 Common Marbles Celypha lacunana were the only other moths I saw in the misty murk.  A Scorpion Fly proved to be Panorpa germanica (gen det).

Next I headed to Dersingham Bog.  I thought there might be fewer moths here with it being further inland, or at least further from a north/east facing coast.  But there were loads of Diamond-back Moths Plutella xylostella here too.  The heath itself was quite windswept and there weren't many here (although still kicking up a few every few steps) but in the shelter of the woodland above the heath there were hundreds.  I didn't spend long here and didn't cover that much ground, but even so I must have easily seen 500.

I managed a few other moths too: 2 Green Long-horns Adela reaumurella, Brassy Tortrix Eulia ministrana, Common Grey Scoparia ambigualis and 3 Common Heaths.


Common Heaths, Dersingham Bog, 4th June


A leafhopper turned out to be Chamaepsylla hartigii, a first for me.  A wildflower tick for me here too, which I might not have noticed if it wasn't for the display board telling me about it.  Cranberry.  The flowers aren't exactly tiny and they're bright pink, yet they were strangely hard to see even when looking down on them.  I must have walked past them before, here at least if not elsewhere.

I wish I'd spent longer trying to get a decent photo of an amazing insect that I found on a log pile close to where I parked.  Turned out none of my photos of it were in focus, which is a bit disappointing.  It was obviously an Ichneumon wasp, but what an Ichneumon!  It was a monster!  An absolute beast!  Off the top of my head I can't think of another insect I have ever seen anywhere in the world as long as this.  The body was probably well over an inch long, the antennae about as long on top and then the ovipositor!  Wow!  I believe it's something called Ephialtes manifestator.

Ephialtes manifestator, Dersingham Bog, 4th June


But good as this was, top trump goes to a hoverfly.  A large and very distinctive hoverfly that I was pretty sure I hadn't ever seen before.  Turns out it was Sericomyia lappona, a species with a relatively restricted range in Norfolk.  Looks like it occurs only in west and north-west Norfolk, and given its preference of boggy habitat I would hazard a guess that Dersingham Bog might be the best place to see it in this county.


Sericomyia lappona, Dersingham Bog, 4th June


To the untrained eye this Hoverfly looks even more distinctive, but alas there are 2-3 similar species and the quality of my photos is not high enough for me to be 100% certain of its ID.  Probably Helophilus pendulus.  Not a greatly significant record even if the ID was clinched (either way).

Helophilus sp., probably Helophilus pendulus, Dersingham Bog, 4th June


My next stop was a little further inland, a footpath close to the Babingley River just south of West Newton.  I've been meaning to explore this path for ages.  The path starts running down the edge of a crop field on one side and on the other, a strip of low vegetation, a dyke and then a hedgerow.  It goes on like this for maybe a third of a mile before crossing a sheepfield and then running alongside the river itself.  I only got as far as the sheepfield.  Being a bit further inland I didn't expect especially huge number of Diamond-backs, although with the numbers I'd seen elsewhere I knew it would hold a good few.  Well, it was spectacular.  I have never seen anything like it.  As soon as I opened my car door a cloud of Diamond-back Moths got up beside me.  But this was only the start - they continued all the way down the path.  Counting them was impossible but I was keen to document how many there were so set about to estiamte numbers as accurately (but conservatively) as possible.  To give you an idea, a single stinging-nettle held about 20 - and that was just the ones I could see without disturbing it.  There were a lot of stinging nettles, and a lot of other plants with moths on.  In just one small section in front of me I could see hundreds, and that went on for pretty much the whole footpath.  A very conservative estimate for just this small stretch of footpath was 10-15,000 Diamond-back Moths.

With so many moths present it was hard to pick out any that were different, but I did manage a few.  Best was a new moth for me, and a very attractive one too - White-barred Gold Micropterix aruncella.  They're not hugely rare (indeed my second followed a couple of days later) but a first is always exciting, especially when they're so stunning.

White-barred Gold Micropterix aruncella, Babingley River near West Newton, 4th June


I also found 5 Cocksfoot Moths Glyphipterix simpliciella, a Common Marble Celypha lacunana and a Drinker caterpillar, but an interesting-looking small Plume moth sadly evaded my net.  Bugs included a number of Hairy Shieldbugs and the striking Cercopis vulnerata.

Hairy Shieldbugs, Babingley River near West Newton, 4th June


Cercopis vulnerata, Babingley River near West Newton, 4th June


Dragonflies included at least 20 Azure Damselflies and about 3 Blue-tailed Damselflies.

Azure Damselfly, Babingley River near West Newton, 4th June


Next stop was Roydon Common where I was to join the Norfolk Moth Survey for an evening's trapping.  I got there early - a lot early - with Dave so as to give ourselves plenty of time to look for day-flying moths before the trapping started.  A good time was had, with thousands more Diamond-back Moths, but I'll save the details for my next post...

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