More Questions Than Answers

[melbellingham]

There is very little activity on the forum at present, not too many moths in my garden either, but it hasn’t stopped me thinking about moths.

I find moths fascinating, and each year I have two goals. The first is that like everyone else who records moths I want to add some new species to my life and garden lists. It is easier to add to my life list, it just means that I have to travel and record on new sites. I usually do this by either visiting specific venues where target species are known to be, but I also always manage to squeeze some mothing equipment into the holiday luggage, 2 or 3 times a year, and our holiday cottages are usually selected with mothing potential as a consideration.

In the 16 years (2003 – 2018) that I have been regularly recording moths in my Great Sutton garden, I have been adding new moths to my list. Easy to do in the early years, but it gets harder, and now I am pleased to record anything new. Although numbers of new macro species are low, I do manage to record more micro’s these days, some that are new with a few that I have possibly had before, but couldn’t identify.

2018 has been a good year in the garden, with my highest ever number of species, and I have recorded four (4) new macro’s and fifteen (15) new micro’s. Unfortunately I failed to identify three (3) micro’s, which was a little disappointing as I think they could have been new species.

The second goal is to hopefully record some of the species that only appear infrequently in my garden. There are many species that I have only recorded once or twice for instance, which I am always hoping to see again.

One of the species that re-appeared this year, after a long absence, is Scarce Umber Agriopis aurantiaria. I first recorded two (2) in 2011, and this year I have recorded three (3) different individuals. Will I record any next year? Only time will tell, but it will be a long wait to find out.

The reasons why I don’t record many individuals or why I don’t record it regularly could be many. Where I live is not typical habitat, as I don’t live close to long established woodlands, which I suspect is the main reason, but the list of larval food plants contains many plant species that appear locally, with some in my own garden. There aren’t many records besides my own in SJ37, and the nearest 2 established woods, are about 1.25 and 1.75 miles away. The shortest route between these woods does not go through my garden.

Some moth species are able to spread quickly in Cheshire, with Vine’s Rustic Hoplodrina ambigua a good example. Several local recorders have now added this species to their garden list in the last couple of years, including myself. Females of the species must be very mobile, otherwise the spread could not be so rapid.

Female Scarce Umber moths are prevented from rapid dispersal, by their lack of wings, the reason I imagine why their habitat needs to be long established. The appearance of three different males in my garden recently, suggests that the males do wander, presumably seeking unmated females. Did they just wander into my garden, or were they attracted into the locality? Once in the garden or flying through, they were obviously attracted to the MV lamp, but why were they there?

Five individuals recorded in two years out of sixteen does not give the impression that they are established locally, but I can’t understand why two of the three individuals recorded this year came on the same night. Does this mean something, or am I looking for answers that are not there?

In December 2011 I found a female Winter Moth Operophtera brumata on the wall adjacent to my garden trap. If it was attracted to the MV lamp, it would have had to descend to the ground from wherever it was resting, presumably in the trees or shrubs along the edge of the garden, walk across a lawn, climb up some stonework to a path, and cross the path to reach the wall. Not the easiest of tasks and one that I have never seen repeated. I do have my own thoughts on another possibility, but it involves something that I have never seen described in any text referring to flightless female moths.

Anyone who has been out looking at butterflies has probably seen mating pairs flying in tandem, usually when they have been disturbed. Could the female Winter Moth have been carried to the wall, whilst in tandem with a male that was attracted to the MV lamp?

Would the male Winter Moth be strong enough to carry a female?

Could this strategy aid dispersal of flightless females to new habitats or locations?

Could a female Scarce Umber have been carried in a similar fashion, to a site not too distant from my garden?
Or could it just be that Scarce Umber is more numerous because it has had a brilliant year? The 2018 Moth Report may give me a clue.

More questions than answers, but one of the reasons why I find moths fascinating. If anyone does have any answers, I’d be interested to hear them.

Mel.

[SteveH]

Hi folks,

picking up on some of Mels points:

We had a very good year here in Elton in 2018, recording 334 species (the best since 2014 and our 6th highest total ever) = it would have been considerably better had we not been away for the majority of September and October but there you go, can't be in two places at once! As a consequence, and for the first year ever, we didn't record Garden Rose Tortrix (amongst other autumnal species) but on the other side of that coin we did have 15 new species during the year, including Vine's Rustic which looks to be heading east really quickly as Ray Bertera also had his first in Frodsham this year too.

Some species also re-appeared after long to very long absences, namely:

Ypsolopha dentella (last was in 2008)
Pammene fasciana (2008)
Meal Moth (2010)
Thistle Ermine (2007) - a species I also found commonly whilst in the field during the year
White Plume (2002)
Large Emerald (2007)
Chevron (2000) and
Bordered White (1997!)

Cheers,
Steve

[CliveJ]

Hi Mel

Re possibility of Scarce Umber female being carried in cop. I have had the same thought myself, after finding one in my light trap along with (though sadly not attached to) a male of the same species. Without a conclusive sighting I guess this must remain merely a possibility, with silk thread parachuting by larvae another one to consider.

See https://www.flickr.com/photos/149980226 ... 658269576/ for my musing on the same topic last year.

Cheers

Clive

[melbellingham]

Hi Clive,

It is interesting to hear that you have had similar thoughts, as a result of a somewhat similar situation to the one that I described.

As you state though, without positive proof it will only remain a possibility.

I had considered the possibility of larval dispersal. Female moths that fly about looking for suitable positions to lay single eggs, or several small batches, must spend a lot of time and energy in the process. With flightless females this is not an option, so perhaps they might lay their eggs in batches.

Roy Leverton, in his book ‘Enjoying Moths’ states that ‘the Peppered Moth Biston betularia (and probably many other species in the same subfamily Ennominae), copy the technique used by many young spiders’.

As the list of larval foodplants used by Scarce Umber larvae is quite varied, there would be a reasonable chance that some could find suitable feeding areas.

Thanks for your comments.

Mel.