Sunday, 29 June 2014

A little experiment (and the one that got away)

Exhaustion had caught up with me by Friday night (27/6), so I abandoned plans to `trap out` and instead trapped at home at Pwll. When out trapping with Chris Manley on Wednesday night, one of our brief conversations (we were too busy attending to our traps to talk much!) touched on how precisely one has to locate a trap to catch a certain species. This conversation had been prompted by a comment by myself that to catch the dew moth (a muslin/footman moth-type rarity that feeds on lichens on limestone) should I put my actinic right next to a potentially suitable area, which was not possible on the night? The dew moth, incidentally, has never ben recorded in our county, but is known from Pembs.
Chris related a story about the fabulous Portland moths that he caught last year in Lancashire, saying that it turned up in one trap but not in the other two nearby traps. I have read of similar stories, with Colin Plant in his excellent Moths of Hertfordshire stating, `a light trap placed thirty foot or so from a Beech tree will usually not attract any Barred Hook-tips yet a light trap placed closely against a trunk will attract several`. He makes a similar, but even more extreme advisory point with the butterbur: `it is absolutely necessary to put the trap well in amongst the plants [ie its namesake plant, butterbur] so that the light will be barely seen!" and he goes on to say that `double figures` of butterburs can be caught thus, but with none just six foot away! There are just a few barred hook-tip records from Carms, but no verified butterbur records. As for Portland moth, the best areas for it in terms of habitat, will be the growths of creeping willow at Tywyn Burrows/RAF Pembrey or MoD Pendine, though a long ride immediately cSE of the RAF seaward observation tower looks good (and is outside the RAF boundary for easier access). There is one 19th Century record from Carmarthenshire.
Anyway, back to my little garden experiment on Friday night. It was VERY unscientific, for lots of reasons, but it involved setting up three traps in the garden just to see what turned up in each trap. The `data` is not at all comparable, as there were so many variables, such as the type of trap etc.
The first (40W actinic)trap was placed in my standard extension roof position, overlooking the garden and the coast to the south, and with a wooded hillside etc to the NW.
                                         Above: `Trap 1` site, with `moth-view` south.

The second (MV) was positioned mid-way in the garden, surrounded by herbaceous borders, shrubs etc and raised up only c 3ft on a garden chair.
                                         Above: `Trap 2` site, mid-way in the garden.

The last (actinic) was put in my `woodland garden` with ferns, trees and close to semi-natural willow carr, poplars etc.
                                         Above: `Trap 3`, amongst ferns at woodland edge.

Many moths were repeated in all three traps, but some were confined to just one trap:
Trap 1 (rooftop) had the only individuals of : double line (perhaps because it overlooks damp pasture to the W), barred red (there are nearby conifer plantings on the hillside above) ....also Brussels lace, burnished brass.
Trap 2 (MV): Perinephela lancealis (a local pyralid, feeds on hemp agrimony of which much grows nearby, including in my garden) small magpie, rivulet, `grey dagger`, small fan-footed wave, common rustic, barred straw (and a rare Carms moth, of which more later). Also a plume moth, believed to be Amblyptilia punctidactyla.
Above: is this A. punctidactyla? It is dark grey `in the flesh`, rather than the brown hue of this photo. I have other photos if required. The stated food-plants (columbines, primroses, woundwort are all frequent in the garden).

Trap 3: woodland garden: large emerald, yellow tail, v-pug, yellow-barred brindle, fan-foot and smoky wainscot.

Nothing can be concluded from the `joking experiment` above, except that if I`d only had one trap out, some species would not have been recorded.
Regarding the `rare Carmarthenshire moth` alluded to above, I was checking the barred straw (my FFY) to ensure it was n`t a spinach (as I`d forgotten the differences) and had moved the adjacent egg carton to get  a better view. In doing so, I revealed another moth - a beautiful hook-tip! I carefully reached for the camera but, without any provocation, up it went, almost vertically and behind me! I could n`t see it anywhere. I`ve recorded this moth once before at Tyrwaun (in 2009, I recall); co-incidentally in that year I also had Pempelia formosa, which again has turned up again this year. I would have liked to have had a photo of the beautiful hook-tip - the `one that got away`.

Some moths recorded (photographed inside the trap):

                                         Above: barred straw.
                                         Above: large emerald (and clouded border).
                                   Above: what I think is a dark form of second-brood engrailed.

I hope to do some trapping tonight, weather permitting.



4 comments:

  1. Your proposed Stenoptilia pterodactyla seems to have been quite a different colour from mine, Ian. Hopefully someone will step forward and help us out! I'm posting a couple more photos in case the one I posted in yesterday's blog isn't good enough.

    ReplyDelete
  2. I actually suggested that mine is Amblyptilia punctidactyla Chris.

    ReplyDelete
    Replies
    1. So you did, Ian. Sorry about that - and I didn't have the excuse of a broken night! I haven't found any more brown ones this morning but I did disturb another White Plume.

      Delete
  3. Don`t worry at all, Chris...remember, when it comes to getting confused and getting things wrong, I`m the World Champion!
    Weather looks as if it`s going to be clear tonight, so may not trap...we`ll see.

    ReplyDelete