(Photo above of a – but not the – Red-Green Carpet. © Andy Harding)
In early March 2018 I ‘penned’ a short note to Magpie1 about a moth, a Pale Brindled Beauty Phigalia pilosaria, which stayed in and around our porch from February 16th to March 3rd, sometimes exposed to inclement weather, but ignoring better days to fly off, until a definite thaw precipitated its departure.
This interesting (to me at least!) sequence of events has been paralleled in recent days by a different species, which stayed for 15 nights. The specific identity of this moth may give a clue to the reason for apparent inactivity, even if conditions seemed conducive to night time flight.
This year’s moth was first seen on the morning of February 21st: a Red-green Carpet Chloroclysta siterata, again adjacent to the outside porch light at around head height. Despite its strikingly vibrant green colour, I didn’t photograph it, since I have plenty of photos of the species. Had I known I was going to write this note, I would have done so!!
This individual, we can be sure, was a female. Males of this species do not survive beyond autumn, but females hibernate and expect to mate with males emerging from mid-March onwards. However this one was three weeks earlier than any I have encountered in Old Stratford in the last 12 years. So early, in fact, that when I entered the record in the 2020/2021 winter Garden Moth Survey spreadsheet, it gave me a warning that it was outside the normal flight period and the record should be checked again before confirmation.
The moth seemed not to have moved at all from night 1 to night 2, but for the next 4 nights moved a few centimetres in different directions and ended up in different attitudes on the same area of brickwork. A bright sunny afternoon then was presumed to force it inside the small porch, where it again moved nightly to different pieces of the brickwork and then to the glass on the front door. Then on March 2nd it moved to the solid (PVC) part of the front door and as far as I could tell it remained in precisely the same spot for 4 nights. After a single night back on the brickwork inside the porch, it disappeared. A check of the porch confirmed it had not simply succumbed in the porch.
The inside of the porch has a light on all night to accompany the exterior light to which it was first attracted. Maximum daytime temperatures varied from 9C to 13C and night-time minima from 5C to 0C, with frosts on three nights. During the period a very modest number of moths visited the two moth traps in the back garden (max of 4) so conditions were not entirely inimical to night-time moth flight.
So why didn’t she move any real distance. Of course, I don’t know, but here is my sixpennyworth, and this may be rubbish. Well, there are two lights very close to her position, so these might be so attractive as to ensure she did not go very far. However moths frequently pitch up adjacent to the lights in and around the porch but usually stay for just one or two nights. So I prefer the idea that this female moth instinctively ‘felt’ she had to move very little. Flight takes up energy which can be better used for egg production, so she may have been pumping our pheromones waiting to attract males, which sadly this early in the year were not likely to have emerged, or so I assume. As I complete this on March 12th we are not quite at mid-month, but soon male Red-green Carpets will be emerging. I like to think she can hang on somewhere for a few more days!
If anyone has more sensible ideas about what was going on here, please send those ideas in to email@example.com.
Footnote: you may wonder why, although I did not photograph this moth when it first arrived, I didn’t do so when putting this little note together. While a brilliant bright green on arrival, it had lost much of its lustre in latter days, as is the way with all green moths!
1 Andy’s earlier article about the Pale Brindled Beauty can be found in The Magpie April 2018