The year’s first sighting in the garden was of a Brimstone on 10th March, while the final one was a Red Admiral on 28th October. A total of 22 adult butterfly species put in an appearance, exactly the average for the last ten years, but the overall count of 583 individuals was by far the lowest (the average over the same period is 1,037). Why there should have been such a drop is anyone’s guess because there was no difference in recording effort, the weather was generally excellent and nectar sources in the garden remained unchanged. Vanessid numbers on our buddleias were well down and towards the end of the season I don’t think I saw any butterflies at all on the copious amounts of ivy blossom around the garden even though it was very well used by bees, hoverflies and other insects.
The only surprise of 2022 was the unexpected appearance of a female Purple Emperor on one of our buddleias during the afternoon of 24th July, becoming the 32nd butterfly species to have been recorded in the garden. She spent a good hour or so feeding from the same couple of flower spikes on the bush, keeping her wings closed and seemingly trying her best to keep out of the bright sunshine (thus making photography a bit of a challenge!).
 |
| Purple Emperor, Westcott 24th July 2022 |
No
fritillaries were recorded on the buddleias this year, but singletons of
Painted Lady did visit
on at least half a dozen occasions between 14th June and 12th October.
Adults of White-letter Hairstreak were active on our elm almost daily between 25th June and 5th July but two individuals was the highest count achieved at any one time. With only one tree remaining alive, the colony’s survival within the confines of the garden will soon be in doubt, although there are other elms in the immediate area which it is doubtless already using. A fresh egg of Brown Hairstreak was found on our garden blackthorn on 4th September but unfortunately the adult managed to avoid being seen.
The Mothing Year
A record 743 different moth species were recorded in the garden during 2022 (383 micros and 360 macros, the full list can be seen here on Google Sheets). The overall moth count saw a significant improvement over 2021, reaching just over 38,000, although it was still below the totals achieved in 2018 and 2019 for a similar amount of effort. Between late March and the end of October two traps were run on most nights, usually a 125wt MV and a twin-30wt actinic although during March and April it was mostly two twin-30wt actinics. Outside those periods just the one actinic light was employed. The table below shows the year’s results with data from the previous nine years for comparison (Nights = number of nights when at least one trap was run; Micro & Macro = total number of species; Count = total number of individual moths).
|
Year |
Nights |
Micro |
Macro |
Count |
|
2013 |
203 |
269 |
306 |
27,438 |
|
2014 |
259 |
293 |
307 |
32,910 |
|
2015 |
298 |
309 |
324 |
33,941 |
|
2016 |
289 |
316 |
315 |
26,697 |
|
2017 |
279 |
326 |
336 |
28,189 |
|
2018 |
286 |
346 |
338 |
42,063 |
|
2019 |
323 |
344 |
355 |
54,400 |
|
2020 |
320 |
345 |
330 |
36,784 |
|
2021 |
335 |
380 |
332 |
29,330 |
|
2022 |
326 |
383 |
360 |
38,146 |
While the individual moth count was significantly better in 2022 than it was in the previous year, there is still plenty of room for improvement. The highest combined count from the two garden traps was 782 on 2nd August and on only one other night did that count exceed 700 (21st July with 706). Looking back, in July 2019 there were seven nights when the combined count exceeded 1,000 individual moths (and reached 1,307 on the busiest), but even those totals pale into insignificance against what was achieved on my best ever night in the garden to date (27th June 2011), when the twin-30wt actinic, operating on its own, managed 1,824 moths counted. Many more flew off during the inspection process, each side of each egg-tray being crammed with moths.
 |
| One side of just one of the eight egg-trays at Westcott on 27th June 2011, more than 270 moths visible with many more having flown away, some moths unidentifiable due to lack of scales. If only nights like this happened every year! |
During 2022 the nightly species count exceeded 100 on 18 occasions, the first on 16th June (124) and the last on 1st August (111) with the best night being 11th July (167). Note that the busiest night for moths (2nd August, mentioned in the paragraph above) only produced 92 species. The night of 19th July actually had potential to have been the busiest of the year if the MV light hadn’t failed without me noticing shortly after it was switched on, so the totals for that night (96 species, 400 moths) came from the twin-30wt actinic alone. It just goes to show how well actinic lights can perform if the weather conditions are favourable. In fact the previous night I’d been trapping away from home in a group session at the Grangelands nature reserve near Princes Risborough where my own contribution to the hillside illuminations was two MV Robinson traps and a 15wt synergetic Heath trap. Tucked in amongst the juniper bushes, the little 15wt on its own brought in more than 130 species.
Looking at individual species, the best performance of 2022 in the garden was achieved, not for the first time, by the little Water Veneer Acentria ephemerella with 2,195 individuals counted (and doubtless a few more missed). Six further species put in totals above a thousand, comprising Common Footman (1,575), Large Yellow Underwing (1,439), Lunar Underwing (1,248), Flame Shoulder (1,235), Setaceous Hebrew Character (1,225) & Common Wainscot (1,067), but there was then quite a gap before the next in line which was Heart & Dart (674).
|
2.008 |
Eriocrania
sangii (leaf-mine) |
28 Apr |
|
12.023 |
Triaxomasia
caprimulgella |
21 Jun |
|
12.026 |
Tineola
bisselliella * |
11 Jul |
|
15.003 |
Caloptilia
populetorum * |
22 Mar |
|
15.008 |
Caloptilia
alchimiella * |
11 Jul |
|
15.018 |
Povolnya
leucapennella |
5 Nov |
|
15.019 |
Acrocercops
brongniardella |
11 Jul |
|
15.037 |
Phyllonorycter
tenerella (leaf-mine) |
22 Sep |
|
35.002 |
Aproaerema
cinctella * |
23 Jun |
|
35.118 |
Scrobipalpa
ocellatella * |
9 Aug |
|
37.044 |
Coleophora
discordella * |
23 Jun |
|
38.038 |
Elachista
rufocinerea * |
30 Apr |
|
45.034 |
Merrifieldia
baliodactylus * |
16 Jul |
|
49.052 |
Cnephasia
pasiuana * |
28 Jun |
|
49.230 |
Epinotia
trigonella |
24 Aug |
|
49.362 |
Pammene
giganteana * |
14 Mar |
|
62.023 |
Pempelia
palumbella * |
18 Jul |
|
|
|
|
|
52.001 |
Raspberry Clearwing |
28 Jul |
|
52.009 |
Sallow Clearwing |
4 Jul |
|
65.016 |
Yellow Horned |
17 Mar |
|
70.034 |
Jersey Mocha |
4 Sep |
|
70.296 |
Rest Harrow |
13 Aug |
|
73.050 |
Wormwood * |
1 Aug |
|
73.300 |
L-album Wainscot |
18 Sep |
*
confirmed via dissection, with grateful thanks to Peter Hall.
Micro-moths
 |
| Mine of Eriocrania sangii on birch, Westcott 28th April 2022 |
 |
| Mine of Phyllonorycter esperella on hornbeam, Westcott 22nd September 2022 (the corridor on the lower half of the leaf is a vacated mine of Stigmella microtheriella). |
 |
| Mine of Phyllonorycter tenerella on hornbeam, Westcott 22nd September 2022 |
Triaxomasia caprimulgella and Pammene giganteana were both caught in pheromone traps, the former coming to the LUN lure (for Lunar Hornet Moth) and the latter to the MOL lure (for Grapholita molesta which has yet to be recorded here). Both species were regarded as uncommon until the more widespread use of pheromone lures over the past few years proved otherwise. Taking the MOL lure out and about in the local area during March and April produced many more records of Pammene giganteana, not only in woodland but also wherever there was a small collection of hedgerow oaks, and I expect it can be discovered anywhere in Bucks where the tree is found. During April I had two more examples of giganteana in the garden which came to the SUS lure (for Pammene suspectana, another species which has yet to be recorded here).
 |
| Triaxomasia caprimulgella, Westcott 21st June 2022 |
 |
| Pammene giganteana, Westcott 14th March 2022 |
The Common Clothes Moth Tineola
bisselliella is decidedly uncommon in my experience, this thankfully being
only my second ever record of it in Bucks.
It was a male which came to the garden actinic trap, presumably a
wanderer from someone else’s house locally or, more likely perhaps, from a
nearby bird’s nest.
It was great to get four new Graccillariid species. Despite its name, Caloptilia populetorum is actually associated with birch and there are fewer than 20 Bucks records, most of them from places like Bernwood Forest, Burnham Beeches, Rammamere Heath and Stoke Common. This sighting appears to be the first county record from a garden and, while we do have birch here, our four trees hardly constitute the quantity of food-plant which the moth is usually associated with. The other three species all use oak: Caloptilia alchimiella is fairly common but needs dissection to separate from Caloptilia robustella (another widespread oak-feeder which I’ve had occasional records of here already); Povolnya leucapennella was first recorded in Bucks in 2011 from Chorleywood and there have been only five subsequent records, all until now from the south of the County; Acrocercops brongniardella with its stunning red eyes (unfortunately not very obvious in the photo below!) is fairly widespread but not often recorded.
 |
| Caloptilia populetorum, Westcott 22nd March 2022 |
 |
| Povolnya leucapennella, Westcott 5th November 2022 |
 |
| Acrocercops brongniardella, Westcott 11th July 2022 |
The appearance of Aproaerema
cinctella means that all three of the common look-alike former Syncopacma species (cinctella, larseniella
& taeniolella) have been recorded
in the garden over the past three years.
The Beet Moth Scrobipalpa
ocellatella underwent a massive explosion in numbers in East Anglia over
the summer and, while nowhere near as abundant here as in counties further
east, moths were recorded right across Bucks including at Westcott. 19 individuals appeared in the garden traps
over 12 nights between 9th August and 11th September. This moth can be a pest of sugar beet crops
but in the UK it is grown mainly in East Anglia and the East Midlands so those
dispersing into Bucks are unlikely to have found anywhere suitable to lay their
eggs.
 |
| Scrobipalpa ocellatella, Westcott 9th August 2022 |
 |
| Case of Coleophora albitarsella on ground ivy, Westcott 28th April 2022 |
 |
| Case of Coleophora binderella on alder, Westcott 21st May 2022 |
 |
| Coleophora binderella (reared), Westcott 18th June 2022 |
The record of Pempelia palumbella
(18th July) must have been as a result of migration because the only prior
Bucks records all come from Stoke Common where it has been resident since about
2008. Ancylosis oblitella also
appeared on 12th September, the only previous garden records being from 2018
when four turned up and are again assumed to have been migrants.
 |
| Pempelia palumbella, Westcott 18th July 2022 |
 |
| Ancylosis oblitella, Westcott 12th September 2022 |
Macro-moths
Once again, clearwing pheromones added new species to the garden list during the daytime, with a pair of Sallow Clearwings coming to the SAL lure mid-afternoon on 4th July and a single rather battered and worn Raspberry Clearwing coming to the HYL lure very late in the afternoon on 28th July. Lunar Hornet Moth, Red-tipped Clearwing, Orange-tailed Clearwing, Red-belted Clearwing and Currant Clearwing also came to their appropriate lures in the garden, leaving only Yellow-legged Clearwing as a no-show amongst those which have been recorded here previously.
 |
| Sallow Clearwing, Westcott 4th July 2022 |
 |
| Raspberry Clearwing, Westcott 28th July 2022 |
 |
| Jersey Mocha, Westcott 4th September 2022 |
 |
| Rest Harrow, Westcott 13th August 2022 |
 |
| Wormwood, Westcott 1st August 2022 |
 |
| L-album Wainscot, Westcott 18th September 2022 |
Two examples of Fern (both rather worn) visited the garden, having appeared only once before in 2017, but
this year I found colonies of this moth as well as Pretty Chalk Carpet in hill-top
woodland on the adjacent Waddesdon Estate where greensand breaks through the
surrounding clay. The larvae of both
species feed on Traveller’s-Joy (a plant of calcareous areas) which is present
there and may offer a more likely explanation for occasional visits to the
garden by other moths usually associated with the Chiltern Hills which lie a
bit further away. One of the examples of
Fern from the garden (as well as another from the Waddesdon Estate) underwent
dissection to confirm that they were not the almost identical recent arrival
Cryptic Fern Horisme radicaria but
that species has yet to be found in Bucks.
Marbled Brown is a rarity in the garden and a single visitor on 3rd May was the first record
here since 2013. Lunar Marbled Brown is equally as rare
and hasn’t been recorded since 2009 despite both species being present in most
of the local woods. Very much like Fern,
Rosy Footman visited twice having put in just a single previous garden appearance back in
2017. Although fairly widespread in the
south of the county it is absent from the north apart from a substantial colony
in Bernwood Forest and that is likely to be from where these visitors were dispersing. An adult Toadflax Brocade visited on 22nd July,
only the second example here after one in 2020, although I did find larvae on
purple toadflax growing out of the pavement in our road last year too. A nice Fen Wainscot on 22nd July was also the second for the
garden after one in 2018. They do seem
to wander occasionally from their normal reed-bed habitat.
 |
| Fern, Westcott 7th July 2022 |
 |
| Marbled Brown, Westcott 3rd May 2022 |
 |
| Fen Wainscot, Westcott 22nd July 2022 |
Numbers-wise, Poplar Hawk-moth and Elephant Hawk-moth had their best ever years here with totals of 105 and 279
respectively (the latter more than double its previous highest total). Amongst the others which put in their largest
ever annual counts were Single-dotted Wave (163), Canary-shouldered Thorn (40), Brindled Beauty (26), Buff Ermine (201), White Ermine (125) and Dusky Sallow (153). The
only unexpected absentees during 2022 were Grass Rivulet (appears here in ones and twos most years) and
Blotched Emerald (usually an annual). Nutmeg went unrecorded for the
second year in a row but Double Dart returned after its unexpected absence in 2021. Of the other local specialities, Pale Eggar, Fox Moth and Lappet appeared as
expected. I haven’t seen Oak Eggar in the garden trap
since 2018 but did record three elsewhere in the county during July, two in
different parts of Bernwood Forest and one in Yardley Chase.
 |
| Double Dart, Westcott 10th July 2022 |
Migrant moths
2022 was an excellent year for moth migration, better even than 2006 which is often quoted as one of the best in recent memory. Westcott missed out on several species which made it this far inland (notably a significant invasion by Striped Hawk-moth) but there was still plenty of interest during the course of the year as shown in the table below:
|
Species |
Total |
First |
Last |
|
Plutella xylostella |
18 |
15 May |
12 Nov |
|
Pempelia palumbella |
1 |
18 July |
- |
|
Ancylosis oblitella |
1 |
12 Sept |
- |
|
Udea ferrugalis |
15 |
10 July |
26 Nov |
|
Nomophila noctuella |
186 |
11 July |
12 Nov |
|
Hummingbird
Hawk-moth |
57 |
20 June |
19 Sept |
|
Jersey
Mocha |
1 |
4 Sept |
- |
|
Vestal |
13 |
8 July |
29 Oct |
|
Rest
Harrow |
1 |
13 Aug |
- |
|
Four-spotted
Footman |
1 |
21 July |
- |
|
Small
Marbled |
1 |
28 June |
- |
|
Silver Y |
57 |
20 May |
14 Nov |
|
Bordered
Straw |
2 |
24 June |
11 Aug |
|
Scarce
Bordered Straw |
3 |
5 June |
27 Oct |
|
Small
Mottled Willow |
2 |
26 Oct |
29 Oct |
|
Delicate |
1 |
24 June |
- |
|
Pearly
Underwing |
1 |
24 Aug |
- |
|
Dark
Sword-grass |
20 |
6 June |
12 Nov |
 |
| Small Marbled, Westcott 28th June 2022 |
 |
| Small Mottled Willow, Westcott 26th October 2022 |
 |
| Delicate & Bordered Straw, Westcott 24th June 2022 |
