Westcott, Bucks - the year 2014 in review

Although preceded by a very wet winter, the weather conditions during 2014 were for once reasonably good for Lepidoptera from spring all the way through to autumn, with a particularly hot spell in July.  This was certainly reflected in the numbers recorded in our village garden at Westcott, to the west of Aylesbury, where the combined total of butterfly and moth species reached a record-breaking 622, surpassing even the achievement of exactly 600 in 2013.

Butterflies:

That said, as far as butterflies are concerned it was a decidedly average year.  22 species were seen, which is quite a good annual total for the site, but none was new to the garden and two of them,  Painted Lady Vanessa cardui and Small Copper Lycaena phlaeas, were very much last-minute appearances at the end of September once the ivy had come into flower.



Painted Lady, Westcott 30th September 2014

Butterfly quantities were generally lower than in 2013.  None of the whites appeared in their usual numbers and, with the exception of the multi-brooded Speckled Wood Pararge aegeria, the browns seemed to be over rather quickly.  Holly Blue Celastrina argiolus was seen just the once, during April, but may well be at a cyclical low point in relation to larval predation by the parasitic wasp Listrodomus nycthemerus.

Numbers of Small Tortoiseshell Aglais urticae were down a little on 2013 but 444 sightings (reaching a peak daily count of 38 individuals on 6th August) was still a very healthy total.  Peacock Inachis io, which peaked at 39 on 22nd July, was also down overall and the species seemed to disappear into hibernation even more quickly than usual.  However, it was pleasing to see that Red Admiral Vanessa atalanta bounced back to have its best year ever in the garden with 234 records up to the end of October.  A peak of 10 individuals in one day was reached on 22nd & 24th August, both on buddleia, and again on 27th September on ivy.  One subsequent Red Admiral sighting on 4th November, in dull conditions with a temperature of only 7°C, was of a single individual performing a couple of quick circuits underneath the massive willow in our front garden, following which it chose a perch on the underside of a large horizontal branch.  It was still present in the same position nearly a week later, hardly the most sheltered of hibernation sites.      

There were no fritillary sightings in 2014 so it was left to the hairstreaks to provide the only real bits of excitement.  White-letter Hairstreak Satyrium w-album appeared in the garden for the second year running, making four appearances during the first week of July all at the top of our lime (Tilia sp.) while the tree was still in flower.  The source of the butterfly was presumably the common elms (Ulmus procera) which stand next to the lime but they have Dutch Elm Disease and are now of an age where they are beginning to die.  However, I’ve had occasional sightings of the butterfly around the village since 2006 and there is a plentiful supply of younger elms following on in the adjacent hedgerows, so I’m hopeful that it will continue to thrive locally if not in the garden itself.  A distant record shot of the initial sighting on 1st July appears below. 




White-letter Hairstreak, Westcott 1st July 2014

The same lime was responsible for the second hairstreak species as well, although by then the tree was no longer in flower.  A male Brown Hairstreak Thecla betulae was spotted at the top of it on 5th August and, again, I did obtain a record picture but that was even more distant!

Moths:

 

Moving on to the moths, overall it is fair to say that most species whose numbers had been so severely depressed since the awful summer of 2012 did bounce back to somewhere near their normal levels.  There were no nights when the trap was overwhelmed but, showing a continuing improvement over 2013, 100 or more species came to it on 12 occasions (two in the last week of June and the remainder during the second half of July).  18th July was the hottest day of the summer locally, with temperatures reaching 30°C (thankfully we managed to avoid the accompanying thunderstorms).  That night’s garden trap produced the best result of the year here with 157 species caught for an overall count of 854 moths.  A similar result on 20th July saw 800 individuals of 153 species come to the trap and on that night it was pleasing to see the micros take the lead for once (83 species, as opposed to 70 macros).  During the course of the year 600 different moth species were recorded within the confines of our garden.

I continue to run a single Robinson trap equipped with twin-30wt actinic bulbs but occasionally substitute the standard 125wt MV light fitting.  Although I choose not to do so, there is just about sufficient room in the back garden to run two traps without them interfering with each other or causing too much grief to the neighbours.  As an experiment I did try this out once during the year, on 28th September, with the lights being placed just under 20 metres apart on opposite sides of a hedge. Although hardly a scientific trial, the results were strikingly similar with one more species appearing at the MV but more individual moths turning up at the actinic.  I’ve listed the details below in case anyone is at all interested in the comparison:

Westcott, 28th September 2014	MV	Actinic
Carcina quercana		1
Acleris variegana	1
Epiphyas postvittana	1
Eudonia angustea	1	1
Hypsopygia costalis		2
Common Marbled Carpet	2	2
Dusky Thorn	1
Light Emerald		2
Large Yellow Underwing	5	5
Lesser Yellow Underwing	1	2
Broad-bordered Yellow Underwing		2
Lesser Broad-bordered Yellow Underwing	1
Setaceous Hebrew Character	2	1
Square-spot Rustic	11	12
Common Wainscot	4	4
Deep-brown Dart	3	4
Black Rustic	1	3
Green-brindled Crescent	1
Blair’s Shoulder-knot		1
Red-line Quaker	1
Beaded Chestnut	29	35
Lunar Underwing	227	282
Pink-barred Sallow	6
Sallow	8	4
Dusky-lemon Sallow		1
Pale Mottled Willow		1
Snout	1
Total:	307	365

In deference to our neighbours I shall continue to use the actinic arrangement for most garden trapping sessions.  The only drawback with the actinic seems to be that it is less efficient than the MV at drawing micro species right inside the trap.  At the height of the season I substitute an 84 litre plastic “Really Useful Box” (with a circular hole cut in the lid) for the Robinson base because its larger size and rectangular shape allows a greater number of large egg-trays to be used.  The main drawback is that having a flat top means it is not at all suitable for use if there is any chance of rain.  We acquired a fairly substantial collapsible gazebo during the year and I began running the light beneath it, not only to get around the problem of rain but also in an attempt to provide a bit of an obstruction to our local Brown Long-eared Bats which were being as much of a nuisance as ever around the trap.  Needless to say it didn’t make much difference to the bats!  However, not only did the gazebo provide the required shelter when it was needed but also its roof and the foot or so of vertical skirting around the roof seemed to provide a very handy spot for some of the smallest moths to collect.  I found that I was potting up as many Phyllonorycter species and the like from the gazebo as I got inside the trap itself.  Previously they may well have been resting unseen on surrounding vegetation.    

34 new moth species were added to the garden list during 2014, taking the overall total to 832.  This was my tenth year of trapping at Westcott and I’m well aware that I’ve now reached the stage where the supply of new garden moths, especially the larger ones, will begin to dry up.  Eight new macros appeared in 2014, taking their count up to 398.  Hopefully there will still be sufficient wanderers, migrants or species expanding their range to get me past the 400 barrier in 2015! 

	New garden macro-moths
374	Yellow-legged Clearwing	9th June
1637	Oak Eggar	26th July
1736	Royal Mantle	2nd Sept
1755	Chevron	26th July
1882	Small Seraphim	26th July
2045	Hoary Footman*	1st Oct
2166	Campion	16th July
2379	Small Rufous*	28th July

*confirmed by dissection



Oak Eggar, Westcott 26th July 2014

Royal Mantle, Westcott 2nd September 2014



Small Seraphim, Westcott 26th July 2014

Oak Eggar Lasiocampa quercus is similar to Emperor Moth Saturnia pavonia in that the males are day-flyers and therefore could well be under-recorded in Bucks.  All the same, the moth must manage to exist at even lower levels than the Emperor because there are so very few Vice-County 24 records of females, which do fly at night and do come to light traps.  Oak Eggar appeared to have a good year in adjacent counties so perhaps its fortunes may be improving here in Bucks too.  In addition to the female which came to light in the garden, one was caught in the Rothamsted Insect Survey trap at Marsh Gibbon on the same night.

For me the Royal Mantle Catarhoe cuculata was the year’s biggest surprise.  A very localised species found on chalk down-land, it was presumably a wanderer from one of its few sites in the Chilterns, the closest of which is about 15 kilometres to the south-east.  The other new arrivals were mostly species which are found locally so could reasonably be expected to turn up in the garden.  Indeed it is surprising that Campion Hadena rivularis hasn’t been recorded before now.     

The good summer weather meant that there were quite a few suitable opportunities to try out pheromone lures for clearwing species in the garden but I was only successful on one day.  On 9th June a solitary Yellow-legged Clearwing Synanthedon vespiformis came to the VES lure at 3.10pm and fifty minutes later I had a single Currant Clearwing Synanthedon tipuliformis to the TIP lure.  Many other attempts ended with the usual result – nothing at all!  Having had Red-belted Clearwing Synanthedon myopaeformis and Orange-tailed Clearwing Synanthedon andrenaeformis here in the past, I’ve probably now seen most of the species I can reasonably expect in the garden, but the most significant failure has been in attracting Hornet Moth Sesia apiformis because there are poplars all around the village which I know are used by the moth.



Yellow-legged Clearwing, Westcott 9th June 2014 

Amongst those moths which weren’t first-timers but nevertheless are rare sightings in the garden were Lesser Cream Wave Scopula immutata (20th July), Pine Carpet Thera fermata (30th September), May Highflyer Hydriomena impluviata (28th April & 19th May), Bordered Pug Eupithecia succenturiata (30th July, first record since 2006), Peacock Moth Macaria notata (19th July), Pine Hawk-moth Hyloicus pinastri (13th June, another species last seen here in 2006) and Dotted Fan-foot Macrochilo cribrumalis (30th June).  Pine Carpet, May Highflyer and Dotted Fan-foot were all recorded for the first time at Westcott in 2013. 

From year to year there are always fluctuations amongst those species with the highest overall counts.  In 2014 Lunar Underwing Omphaloscelis lunosa was the runaway winner with 3,570 individuals recorded in the garden trap during the moth’s relatively short flight season which lasted from 11th September until 25th October.  Most of the other “big hitters” had either a longer flight period or two broods over which to achieve their totals.  Heart and Heart Agrotis exclamationis (2,083 individuals) was back close to where it should be in the league table after a dip in its fortunes but the numbers of Large Yellow Underwing Noctua pronuba (967) still seemed to me to be somewhat depressed even though the species has recovered a little ground since its low point two seasons previously.  The moth’s flight period was spread over five months (29th May to 31st October) and the highest nightly total achieved was 46 on 29th August.  Until the crash of 2012 I could guarantee several nights with 100+ totals of Large Yellow Underwing each year. 

	Top 20 Highest Counts
20	Pleuroptya ruralis	331
19	Common Quaker	357
18	Eudonia mercurella	360
17	Smoky Wainscot	385
16	Dingy Footman	407
15	Brimstone Moth	416
14	Hebrew Character	445
13	Setaceous Hebrew Character	445
12	Riband Wave	458
11	Beaded Chestnut	507
10	Agriphila tristella	630
9	Flame Shoulder	646
8	Dark Arches	701
7	Common Footman	714
6	Chrysoteuchia culmella	758
5	Large Yellow Underwing	967
4	Agriphila straminella	1004
3	Square-spot Rustic	1626
2	Heart and Dart	2083
1	Lunar Underwing	3570

It was great to see a micro-moth break through the thousand barrier and achieve 4th place in the table with 1,004 individuals.  Chrysoteuchia culmella, Agriphila straminella and Agriphila tristella (and in fact the “grass moths” in general) all had a really good year in the garden.  The same is true of Dingy, Scarce and Common Footman which all had their best ever counts here.  Although totally unrelated other than by their vernacular names, by co-incidence both Hebrew Character Orthosia gothica and Setaceous Hebrew Character Xestia c-nigrum achieved exactly the same total, coming in at joint 13th place with 445 individuals.  Lesser Broad-bordered Yellow Underwing Noctua janthe made 10th place last year but in 2014 its total of 326 was only good enough for 21st place.  Of the geometrid macros Brimstone Moth Opisthograptis luteolata (416) put in its best ever performance in the garden although the total was only a modest rise on that achieved in 2013.  The biggest surprise was Riband Wave Idaea aversata (458) which trebled its previous highest count here.  Two other species which had very noticeable improvements in their fortunes even though they failed to make the Top 20 were Chinese Character Cilix glaucata (215) and Clouded Border Lomaspilis marginata (260).     

Even though it was such a good year for numbers of species seen, there were several unexpected absentees during 2014.  For the first year since I started to rear them annually (2006) I failed to “assemble” a single male Emperor Moth to a captive-bred female, either in the garden or anywhere else for that matter.  As luck would have it, on 24th April a gravid female came to light in woodland in the north-west of the county and she left me a quantity of eggs which have been reared through, so I should therefore be able to try “assembling” again in 2015.  Although I don’t get them every year, neither Mallow Larentia clavaria nor Puss Moth Cerura vinula appeared in the garden trap and the absence of the latter came as a particular surprise because it seemed to have a good year elsewhere.  Of perhaps greater concern was the lack of White Satin Leucoma salicis, Least Black Arches Nola confusalis and Svensson’s Copper Underwing Amphipyra berbera which are all usually regulars here.      

Moving on to the micro-moths, 26 new species were added to the garden list during the year, two of them as leaf-mines and the remainder as adult moths in the trap:

	New garden micro-moths
25	Ectoedemia intimella (mine)	11th Oct
99	Stigmella hybnerella (mine)	21st May
196	Morophaga choragella	20th July
254	Leucoptera laburnella*	12th May
283	Caloptilia betulicola*	3rd April
287	Caloptilia robustella*	5th May
301	Parornix betulae*	5th Aug
320	Phyllonorycter quercifoliella*	18th July
321a	Phyllonorycter platani*	4th Sept
391	Glyphipterix simpliciella	12th May
512	Coleophora binderella*	1st July
581	Coleophora taeniipennella*	30th June
622	Elachista adscitella*	24th June
772	Carpatolechia fugitivella*	15th July
877	Stathmopoda pedella	17th July
962	Cochylis roseana*	19th July
971	Pandemis cinnamomeana	4th Sept
1099	Endothenia marginana*	5th July
1116	Ancylis comptana*	27th Aug
1145	Epinotia nanana*	18th July
1168	Gypsonoma sociana*	13th June
1200a	Eucosma parvulana*	15th July
1303	Agriphila selasella*	30th Sept
1334a	Scoparia basistrigalis*	30th June
1366	Pyrausta nigrata	18th July
1385	Ebulea crocealis*	14th July

*confirmed by dissection

 

Morophaga choragella, Westcott 20th July 2014



Stathmopoda pedella, Westcott 17th July 2014



Pyrausta nigrata, Westcott 18th July 2014



Ebulea crocealis, Westcott 14th July 2014  

Even though it was a rather worn specimen, the large tineid Morophaga choragella was nice to see in the garden because it is really more of a woodland moth, its larvae feeding on bracket fungus.  Two individuals of the tiny Leucoptera laburnella were netted during the daytime on consecutive dates in May while second-brood individuals came to the trap in July, so it must be quite well established on at least one of the Laburnum trees (Laburnum anagryoides) in neighbouring gardens.  Phyllonorycter platani came as something of a surprise but in the village, about 300 metres from the garden, there is a single mature roadside London Plane (Platanus x hispanica) and mines of this adventive species have been found on it for the past three years.  Stathmopoda pedella, with its distinctive resting posture, seems to be quite a rare beast in Bucks and this is only the third record for VC 24.  Its larvae feed within the fruit of alder (Alnus glutinosa) but the single bush in our garden isn’t old enough yet to have fruit so the moth may well have wandered in from nearby Woodham where there are plenty of various alder species covering an old waste tip.  Both Ancylis comptana and Epinotia nanana were nice records, the former being mainly a species of chalk down-land while the latter is associated with coniferous woodland.  Of the two pyralids, Pyrausta nigrata was the most unexpected, presumably being another wanderer from the chalk, but Ebulea crocealis is a moth of damp places and I do seem to get quite a few species here which like that kind of habitat.  In 2014 I was pleased finally to see an adult of Bedellia somnulentella, the mines of which have been found on bindweed in the garden on several occasions in previous years.
 

Searching for leaf-mines provided the usual autumnal boost to the garden year-list although only two completely new species were discovered, of which the most pleasing find, illustrated below, was an active mine of Ectoedemia intimella from our large willow (a Salix babylonica hybrid).  The mine was actually found on a fallen willow leaf which had already started to decay, but through a chemical reaction the caterpillar is able to fool the chlorophyll into continuing to function in the part of the leaf which it is still eating (making a ‘green island’), thus giving it sufficient nourishment until it is ready to pupate.



Mine of Ectoedemia intimella, Westcott 11th October 2014

The list below shows 18 other species which were recorded in the garden during the year only as leaf-mines:

	Leaf-mines
50	Stigmella aurella	Bramble
63	Stigmella lemniscella	Elm
67	Stigmella plagicolella	Blackthorn
68	Stigmella salicis	Sallow
80	Stigmella ulmivora	Elm
92	Stigmella anomalella	Dog Rose
95	Stigmella viscerella	Elm
100	Stigmella oxyacanthella	Apple
107	Stigmella regiella	Hawthorn
111	Stigmella microtheriella	Hornbeam
260	Leucoptera malifoliella	Apple
271	Bucculatrix albedinella	Elm
275	Bucculatrix bechsteinella	Hawthorn
310	Callisto denticulella	Apple
330	Phyllonorycter cerasicolella	Cherry
352	Phyllonorycter schreberella	Elm
356	Phyllonorycter tristrigella	Elm
363	Phyllonorycter platanoidella	Maple

Several additional mines were found but their corresponding adults were also recorded.  As can be seen, the above table contains a good number of Stigmella species.  I had actually retained several adult nepticulids from the trap to be looked at by Peter Hall but without exception they proved to be female and therefore not ‘do-able’ by dissection.  This goes to show that searching for these distinctive early stages, even in gardens, is very useful and often the easiest way of obtaining records for some of our smallest micro species. 

2014 was not an exceptional year for migrant species in the garden.  I had Diamond-back Moth Plutella xylostella and Rusty-dot Pearl Udea ferrugalis regularly between June and November (peaks in July and August respectively) but there was no sign of Rush Veneer Nomophila noctuella nor any of the rarer micro migrants.  Macro-wise the garden was visited by a single Vestal Rhodometra sacraria on 27th September and by a Delicate Mythimna vittelina on 31st October.  Dark Sword-grass Agrotis ipsilon put in six appearances in September and October (fewer than normal), while visits by White-point Mythimna albipuncta on four occasions during August and September are probably now suggestive of locally-grown individuals rather than migrants because the moth is certainly resident in the southern half of the county.  Hummingbird Hawk-moth Macroglossum stellatarum did quite well with 25 daytime visits to the buddleias between 6th July and 10th September but Silver Y Autographa gamma had a relatively poor year with only 30 of them recorded in the trap.   



Delicate, Westcott 31st October 2014

The excellent weather in July not only prompted moth dispersal but was probably also the reason why a number of species were able to produce an unexpected extra brood in the autumn.  Unusually late sightings at Westcott included Pleuroptya ruralis (15th October), Short-cloaked Moth Nola cuculatella (3rd October), Vapourer Orgyia antiqua (19th October) and Shuttle-shaped Dart Agrotis puta (23rd October). 

As ever, my grateful thanks go to Peter Hall for confirming by dissection examples of many of the difficult-to-identify moth species caught during 2014.  Without this help the garden list would have been much the poorer.