Sunday, 25 November 2018

Scarce Umber - new for Dingestow

After all the excitement of recent migrant near misses, I figured last month's Delicate and Streak were the final firsts for Dingestow of 2018.  However, a mild(ish) night on 24th November combined with friends staying to persuade me to put the MV out.  The 5 species that appeared included a gorgeous Scarce Umber, which I was excited about as I've only seen one or two in my life.  What I didn't realise was that none of my previous sightings came from Dingestow - later checking revealed Scarce Umber to be new, and the 403rd Macro for the site.  This seems to be a genuinely scarce moth in Gwent/Wales, with a south-easterly distribution.  It is surely the last addition for the year, although forecast southerlies midweek may produce another migrant...

Saturday, 17 November 2018

November (lack of) migrants


The nights of 15th and 16th November 2018 delivered Sahara Dust to Britain and plentiful migrants to many moth'ers (including some in Gwent, I hope). Numbers to MV at Dingestow were pretty good, with 30 species on 15th and 15 on 16th, but migrants on 15th were limited to 5 Dark Swordgrass, 4 Silver Y, 2 Plutella xylostella and 1 Udea ferugalis, with singles of the first three of these on 16th.  I was a tad disappointed!  Highlights were 2 Dark Arches and 1 Brimstone, neither seen previously here in November, plus a couple of Sprawlers.


Thursday, 8 November 2018

Woodland Migrants

You wouldn't call mum's secluded woodland garden a hotspot for migrant activity, yet on the 21st October, she recorded this fine female Convolvulus Hawk-moth) Agrius convolvuli) and on 6th November, The Delicate (Mythimna vitellina). Other potential immigrants recorded during the same period were Dark Sword-grass (Agrotis ipsilon) and Silver Y (Autographa gamma). Glyn Wood, Tintern.

Wednesday, 17 October 2018

16/10 - Delicate and Streak

Another strong southerly airflow finally delivered a new migrant moth to Dingestow: my long-awaited first Delicate.  It was accompanied by 2 Vestals, 2 Dark Swordgrass and 1 Diamond-back, along with a good range of resident species.  Surprise of the night was a gorgeous Streak, the first of this allegedly 'common' species that I've seen anywhere.  These are Macros 401 and 402 for Dingestow, taking the moths total to 933.

Sunday, 14 October 2018

Stormy nights

Strong southerlies in early October tempted me to trap 7 times, producing big catches (>100 moths of >30 species several times) and a few migrants.  Highlight was a Scarce Bordered Straw on 13/10 (although moth'ers across Britain caught much better species that night).  Notable species were:

2/10: 1 Dark Sword-grass

3/10: 1 Figure-of-eight, 1 Brown-spot Pinion

4/10: 1 Bright-line Brown-eye (2nd gen), 1 Small Fan-footed Wave (2nd gen)
8/10: 1 Brown-spot Pinion, 1 Large Wainscot
10/10: 2 Turnip
11/10: 1 Yellowtail (2nd gen), 2 Large Wainscot, 1 Figure-of-eight

13/10: 1 Scarce Bordered Straw, 1 Beautiful Hooktip (2nd gen), 1 Large Wainscot, 1 Figure-of-eight, 1 Zelleria hepariella

Also really good counts of Merveille du Jour, Barred Sallow, Dark Chestnut and other autumn species

Thursday, 11 October 2018

Oecophora bractella larva

I visited Graig Wood in the Wye Valley yesterday with 4 NRW colleagues to discuss the provision of deadwood in NRW managed forestry in/adjacent to SSSIs. We prised off some bark on a fallen Beech to look for bettles and spotted this micromoth larva (photographed by Rob Bacon).  It's Oecophora bractella - one of the Wye Valley's special inverts - being too dark for the commoner Esperia sulphurella and with the head the wrong shape for the much rarer Dasycera oliviella.

Sunday, 30 September 2018

Small Chinamark tubes in Undy

Keith Jones, from Undy, sent me this photo and fascinating email.

On the 16th of August I noticed that my pond, which a few days before had been covered with duckweed, was almost completely clear of the plant. On looking more closely I noticed a number of tubes that appeared to be made out of duckweed leaves and these tubes were moving slowly about on the surface of the water although there was no wind to cause the movement, meaning that there was something in the tubes causing the motion.
At first I thought of Caddis fly larvae that build tubes to hide in but I thought they usually crawled about on the pond bottoms not on the surface. I didn't do any more about the puzzle of what the tubes were at once but a few weeks later I read that Small China-mark larvae fed on duckweed and then a few weeks later still I looked the moth up on ukmoths and discovered that the larvae build little tubes - so the mystery was solved.
Checking the two photographs I took at the time of parts of my small pond (c 2m by 1.5m) I counted over 150 of the tubes so there must have been well over 300 in total!

This was followed soon after by an email from Keith discussing both the abundance of Cataclysta larvae and their subsequent rapid disappearance:

A few days after I took the photographs of the tubes I noticed that most of them had gone, which I assumed was due to a number of possible reasons
- they had been predated
- they had pupated
- they had all died through lack of food
- or a combination of these
Under normal circumstances, in say a reen or ditch full of duckweed, the larvae would be hidden from view munching away at the duckweed leaves while camouflaged by their tubes.
In the case of my pond, however, there may have been so many larvae that they had eaten all the limited amount of duckweed leaving their tubes out in the open in plain view where I happened to spot them.
So which of my possible reasons for their subsequent disappearance is the correct one?
I rule out the first because there are no fish in my pond which might eat them although there could be some other predator.
I'd like to think it was the second one but that it was most likely the third one with any surviving larvae scavenging the tubes of the others until all were gone, or....