A paper published in 2018 (cited as Kurze, S., Heinken, T. & Fartmann, T. Oecologia (2018) 188: 1227. https://doi.org/10.1007/s00442-018-4266-4) has found that nitrogen enrichment in host plants increases the mortality of common Lepidoptera species.
The study involved testing the response of larvae of five common butterfly and moth species to host-plant fertilization using fertilizer quantities usually applied in agriculture. The species involved are Small Heath, Speckled Wood, Small Copper, Sooty Copper (not found in Ireland or Britain) and two moths, Straw Dot and Blood Vein.
Nitrogen fertiliser was applied to two host plant species, Annual Meadow Grass used by Small Heath, Speckled Wood and Straw Dot and Sheep’s Sorrell used by the Small Copper, Sooty Copper and Blood Vein.
Nitrogen fertiliser kills caterpillars
The researchers found that the addition of nitrogen decreased the survival of all six species by at least one-third. Richard Fox of Butterfly Conservation UK commented that increases in larval mortality range from 33%-80%. This study presents the first evidence that current fertilization quantities in agriculture exceed the physiological tolerance of common Lepidoptera species. The results suggest that (1) the negative effect of plant fertilization on Lepidoptera has previously been underestimated and (2) that it contributes to the range-wide decline of Lepidoptera.
There are further issues that arise from the study. The situation may be considerably worse than the study found. Applying 90 kg of nitrogen per hectare per year would be likely to remove Sheep’s Sorrel and Annual Meadow Grass from agricultural grassland altogether. The reason for this is that these plants will be out-competed by coarser, aggressive grasses that respond to increased nitrogen by growing at a fast rate. The result would be to remove these host plants so that the habitat would no longer contain the resources needed for these Lepidoptera. Even if this is not the case the increased fertility produces a greener, lusher sward where temperatures are lower, delaying or even preventing larval development. In addition, nectar resources for adults are usually lower than required as grasses out-compete nectar-rich flora.
Furthermore, while application rates of nitrogen on grazing land in Ireland varies, 120 kg of nitrogen per hectare is often applied. It is highly unlikely that the Small Heath or Small Copper can survive on these grasslands. Teagasc, the state agency providing research, advisory and education in agriculture, horticulture, food and rural development in Ireland advises farmers on nitrogen application rates. For dairy grazing, these can rise to 210 kg of nitrogen per hectare per year.
Under such an application regime it is no surprise that butterfly and moth species are being eliminated from the landscape, or why such formerly widespread and abundant species like the Small Heath and Wall Brown are now in serious trouble.
Research needed to save farmland butterflies
Research should be carried out to determine the rate of nitrogen application that grassland Lepidoptera species can tolerate. The Sooty Copper was able to cope with 30 kg of nitrogen but the other species studied were not assessed for nitrogen tolerance. A study of biodiversity richness under the full range of nitrogen inputs it advises (including nitrogen added by slurry applications) should also be undertaken by Teagasc. Nitrogen application should be reduced or prohibited on farmland adjoining land designated as Special Areas of Conservation and National Heritage Areas to ensure these areas are not contaminated.
This issue can be addressed. Forcing land to produce more food by pouring chemicals into the soil cannot continue at the expense of biodiversity, water quality and possibly animal and human health and our world in general. Butterfly Conservation Ireland will take up the issue with Teagasc and urge the organisation to undertake the research needed to assess the impacts of nitrogen application on biodiversity on Irish farmland and alleviation and amelioration strategies. Good farming and good wildlife conservation must be the outcome if wildlife is to survive in today’s farmed landscape.
Last Autumn we were contacted by Peter Cunningham from Westmeath – about a special exhibition of butterfly-themed art launching in early October in the parish of Drumraney County Westmeath.
Peter explained that he and fellow parishioner Christy Grimes were arranging an exhibition of artworks by three disabled artists from the UK – Christine Bielby, William Birch and Elaine Garsden. The artists are keen butterfly enthusiasts and wished to donate all proceeds from the exhibition to Butterfly Conservation Ireland. I was honoured to attend the exhibition on behalf of BCI – to meet the three artists and their carer Linda Lord – and the many people of Drumraney parish who attended and supported the exhibition on the night.
Christine, Elaine and William have been visiting Drumraney for many years and join the community every year for several months – living in a house close to the Holy well of Saint Enán – a hermit who established a monastery in Drumraney around 588AD.
Over the years Linda has managed the area around their home in harmony with nature – planting additional native trees and by creating a large pond area. Christine, Elaine and William tend the garden and sow wildflowers to support butterflies, bees and other pollinators.
The exhibition was hosted by Fr Oliver Devine in the parish Church of the Immaculate Conception on October 4th, which appropriately is the feast day of St Francis of Assisi. Before the exhibition launch – at a mass to celebrate the feast day – Fr Oliver said the artists were following in the footsteps of St Francis, who found God in the beauty of nature. He spoke of how the hermit St Enán was closely connected to the wildness of the locality – and how appropriate it was now that the area was maintained and cherished by Christine, Elaine, William and Linda.
A power-point presentation in the church displayed photographs some of the work carried out at their home and garden and showed the artists preparing for the exhibition. The source of inspiration for their art was clear to see in the images shown, which were filled with amazing greenery and colourful wildflowers; it looks to be an ideal habitat for many of our butterfly species.
Peter explained to me that William, Christine and Elaine had joined the parish prayer group some years ago and from time to time they presented him with drawings and paintings. When they expressed a wish to hold an exhibition someday, Peter and Christy Grimes decided that they would organise the exhibition in Drumraney church. With Linda and Christy’s support, the three artists dedicated several months leading up to the exhibition to completing the many beautiful works which lined the walls of the church.
Last week I was invited back to the parish to accept an amazing donation of €425. Butterfly Conservation Ireland would like to express sincere gratitude to the people of Drumraney for their incredible generosity and hospitality.
We’d like to thank Peter, Christy and Linda for the considerable work that they put into setting up the exhibition and to Fr Oliver Devine for hosting the event.
Most of all we want to thank Christine, Elaine and William. It was inspiring to witness their wonderful talents and their genuine love of nature and butterflies. I look forward to visiting them again when they return to Drumraney next year.
The following article has been revised and re-issued due to the volume of queries we receive concerning butterflies over-wintering in houses.
In Ireland, we have four butterfly species that over-winter in the adult form. We have a number of moths that hibernate as adults. One of these is the iconic Herald moth. A group of this species will sometimes shelter in your attic to wait for spring.
The Small Tortoiseshell butterfly has a habit of regularly entering rooms in houses to pass the winter (Occasionally, the Peacock will enter a house to over-winter, although this is unusual). The Small Tortoiseshell, a beautifully marked butterfly likes to stay close to us in late summer and will even stake out likely hibernation sites indoors especially during August and September before settling to fold its wings for winter in some obscure spot in our homes, sheds or even cars!
This well-studied butterfly has some fascinating characteristics. It has shown an ability to relocate specific sites when it has been disturbed from the site, suggesting a spatial memory; if a nettle on which a female is laying her eggs is moved, the female returns to the spot where the nettle was located, not to the site it was removed to. The butterfly is very mobile and some of ‘our’ Small Tortoiseshells may have travelled from Britain and Europe. Males establish and defend territories but if he finds a female he switches to defending the female from other males. She makes him work hard by flying away at speed to see if he can keep up. Sometimes a female (perhaps a female that has mated already) will fly into territory held by other males to enable her to escape in the ensuing confusion. A suitor may have to fight several males throughout the rest of the day. He will drive them away by engaging in a series of aerial combats, with high altitude climbs when he tries to fly above the intruder. When the intruder is expelled, the male returns to a co-operating female who usually remains perched where he left her.
Sometimes, though, she gives him the slip, giving him an anxious search as he inspects the surrounding nettle bed for her. Some females hide, and later accept defence by another male. Even a female who has cooperated with a male all day tries to lose him when she goes to roost in the nettles in the evening by dropping into the nettles and running along the ground. If the male manages to stay with her, she suddenly becomes quiet and allows mating, which lasts all night. Presumably, her demanding behaviour ensures that only the fittest males father offspring, ensuring the health of the next generation. This provides a fascinating example of selection by the female of the fittest male.
Another, related feature of the butterfly is its impressive longevity. The over-wintering generation is long-lived, and individuals can survive for 10 months. The impressive life-span allows the female Small Tortoiseshell the chance to be selective; most female butterflies accept the first male encountered; these females lack the luxury of extended life to test male powers of endurance.
However, our Small Tortoiseshells have one significant challenge when they enter our homes to see out the winter in our bedrooms, living rooms and hallways. The butterflies are very careful to select the best spots, picking excellent hiding places in curtain folds, behind mirrors and pictures, in unused chimney brests, behind dressers and, to complete the concealment, their dark cryptic coloured undersides blend nicely with their chosen surface. However, the mod con that is central heating confounds their attempts to complete their winter slumber. Heat rouses the butterfly, causing it to believe that spring, with its sunshine, flowers and nettles beckon it to fly outdoors. The confused butterfly flies around lights and windows, trying to get out.
Householders who release the butterfly into the winter are usually dooming it. The butterfly rapidly loses the ability to fly when its body temperature plummets in the cold and is picked off by birds or mammals. The other problem is starvation. The butterfly built up vital fats by gorging on nectar in our gardens and countryside before switching off for winter and long periods of unseasonable activity reduces these reserves.
What should you do if you encounter an active Small Tortoiseshell in your home?
If this happens in warm spring weather release the butterfly in the knowledge that it’s time to let it go. It is now ready to feed on the spring flowers, move in search of territories, breeding grounds and mates.
If the butterfly wakes up in winter do not release the butterfly. It should be placed in a dry, transparent container lined with a folded section of kitchen roll to absorb moisture and placed in the salad drawer in the fridge, where the temperature is around four Celsius. The butterfly will soon settle and can be kept there until warm, sunny weather arrives in March or April. Alternatively, remove the butterfly from the container when it is quiet and place in an unheated shed or room to complete its winter rest.
If the butterfly has been flying around for some time, it may need to be fed. Dissolve sugar or honey in a few millilitres of hot water, allow it to cool and use a cotton pad to absorb the sweetened solution. When cool, place the calmed butterfly (cooled in the salad drawer but not long enough to be made fully docile) on the pad, in softly-lit mild conditions. It should begin to feed. When it has finished, place in a cool place to sleep.
We advise against placing a hibernating butterfly in a very dark place such as a cupboard under the stairs. While cool and dark, it usually remains cool even when warmer temperatures return in spring. The result is that the butterfly never wakes up and will eventually die unless you find and release him/her.
Over the years I have successfully over-wintered adult Small Tortoiseshells and felt a burst of delight to watch the butterfly surge into the sunshine in spring. Interestingly, the released butterfly does not loiter. It flies strongly away, as though hyper-energised by the promise of brightness and freshness of a world renewed by the return of sunshine.
The site management event planned by Butterfly Conservation Ireland and the Burrenbeo Trust for Fahee North/Termon in the Burren on Saturday 2nd November has been postponed because the weather forecast is for heavy rain and high winds. We hope to hold the event in February 2020 on either Saturday 15th or Saturday 22nd of February according to the weather.
The site is beautiful and very rich in butterflies and moths so it really is important to keep it in great condition.
A cool, sunny day on Saturday 26th of October made for very pleasant working conditions on our Kildare reserve. An enthusiastic group tackled scrub re-growth from around five years previously. The area we worked on has breeding habitat for Brimstone, Marsh Fritillary, Dark Green Fritillary and Wood Tiger among several other species. The area has a mosaic of habitats packed into a small area attractive to a diverse range of species with very different foodplants and specific micro-habitat needs.
We took a number of steps to cater for all these species. Dense willow and dense birch was cut down but two tree species growing among the birch and willow-Alder Buckthorn and Purging Buckthorn, the foodplants for the larva of the Brimstone butterfly and Holly Blue butterfly were identified and spared. The buckthorns now have more light around them. This makes them more suitable as breeding plants.
By clearing and removing the scrub, we made Common Dog Violet plants, used for breeding by the Dark Green Fritillary butterfly, open to the light. Rough vegetation near the violets was preserved so that the caterpillars will have areas to hide in and to bask on during sunny weather next spring.
Another issue to deal with was a flush of birch saplings. These threaten to out-compete St John’s Wort used by the Wood Tiger caterpillars and Devil’s-bit Scabious used by the caterpillars of the Narrow-bordered Bee Hawkmoth and Marsh Fritillary butterfly. We uprooted these, which yielded readily due to the soft soil.
All uprooted and cut material was placed in a pile to the north to avoid casting a shadow on breeding areas. It was heartening to step back and look at what we achieved and we know our butterflies and moths will thank us for it!
As usual, we had great conversations about a range of subjects, enjoyed the food we brought and shared. Conservation is about people too!
A special thanks to everyone who worked so hard and to all our members and supporters.
Kildare County Council has refused permission for a solar farm and other works on Drehid North, Timahoe, County Kildare. Butterfly Conservation Ireland objected to the application early this year (see https://butterflyconservation.ie/wp/2019/02/19/butterfly-conservation-ireland-lodges-objection-to-proposed-solar-farm/)
The development would involve drainage of part of the site and this would have damaged or destroyed wet heath, a habitat listed on Annex I of the Habitats’ Directive. In addition, the planning authority was unsatisfied with the Environmental Impact Assessment Report, which, it seems, did not include important data required under the Habitats’ and Birds Directive specifically the identification of species and habitats protected under these directives. Butterfly Conservation Ireland drew attention to some of these deficiencies in our original objection, such as the failure to identify the presence of the Marsh Fritillary which breeds on the site.
Following the original application, Kildare County Council called for additional information. In an attempt to protect the habitats and moth and butterfly species on the site, some of which are very important, Butterfly Conservation Ireland worked with the ecological consultants for the project to develop a plan to avoid construction on the habitats that are important to the butterflies and moths and to create a management plan to preserve the habitats and populations present. Butterfly Conservation Ireland submitted the contents of the plan to the planning authority, indicating that the plan if implemented, would protect the habitats that contain the high diversity and high abundance of Lepidoptera species.
The implementation of the plan is very important, as natural succession in the form of semi-natural woodland is changing the grassland habitats and will lead to population declines and to important species being lost.
Refusal of permission will mean that the wet heath is preserved. This is important for some bird species and some moths. However, the greatest diversity of Lepidoptera species is located outside the heath, on the semi-natural grassland, the area that is subject to successional change. The best outcome is that the plan to control invasive scrub is put into effect. Butterfly Conservation Ireland will press for the management plan to be implemented.
It should be reiterated that clean energy, such as solar energy, is welcome as part of the response to reduce carbon emissions. The Drehid site is very large and an area that has very poor habitat could have been selected by the applicants, a point Butterfly Conservation Ireland made in our objection in January 2019. In fact, however, it would be much better to avoid peatland sites altogether. We hope this lesson will be heeded for any future application.
The phrase “climate change” is inescapable right now. I heard the phrase used in the budget speech in the Dáil. I heard the term in a House of Commons debate on Tuesday 8th October. It is used everywhere, on TV, radio, online. It is used in school textbooks so everyone, young and old, is familiar with it. It has fired campaigning zeal especially from the young. Concern about climate change is not new. In The Great Gatsby, the American novel by F. Scott Fitzgerald published in 1926, Tom Buchanan expresses his confused view of climate change:
“I read somewhere that the sun’s getting hotter every year,” said Tom genially. “It seems pretty soon the earth’s going to fall into the sun-or wait a minute-it’s just the opposite-the sun’s getting colder every year”.
Tom does not comment on anthropomorphic climate change, the subject of most of today’s climate discourse but his remarks show an awareness of climate change.
Climate change is ‘normal’. It has occurred throughout history and pre-history. The nineteenth-century saw some very curious weather patterns in these islands. We had damp, warm weather in the second half of the 1840s, good weather for the most part from 1850-1877 and mainly colder conditions for most of the rest of the nineteenth century with the occasional warm, sunny summer (1893).
We have had some bitterly cold winters and even cold years. This most notably happened in the years 1739-1741 when bitterly cold weather killed an estimated 310,000-480,000 people out of an Irish population estimated at 2.4 million. This killed up to 20% of the Irish population, a far higher percentage than those killed by The Great Famine 1845-1850. The seas froze, cattle and sheep died of the cold, crops failed. The frozen Shannon was crossed on horseback.
No cause has been identified for this remarkable climate event. Climate change expert Professor John Sweeney of the Irish Climate Analysis Research Unit (ICARUS) at Maynooth University said the cause of the catastrophic winter of 1740-41, often referred to as the mini Ice Age, remains a mystery.
Where does this leave us today? While I am not a climatologist, I feel that the current focus on climate change is probably somewhat misplaced. Butterfly and moth populations are often seen as indicators of climate change. Many species have very particular requirements that are easily upset by change. The immature stages are the most sensitive. The larval stage is the growth stage and without the correct conditions, larvae do not develop. Pupae formerly believed not to be particularly sensitive to damp have recently been demonstrated to suffer from prolonged exposure to rain in a number of British and Irish species.
However, in the most recent assessments of our butterfly and moth populations published by the National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht, Dublin in 2010 (butterflies) and 2016 (macro-moths) which assessed the conservation status of 30 butterflies and 501 macro-moths (the larger moth species) pointed mainly to habitat change as the cause of declines. Climate change is not mentioned in relation to the conservation status of any of the butterflies assessed.
Only three of the 501 moths were stated to be negatively affected now or predicted to be negatively affected in the future by climate change; these are Red Carpet (“Habitat loss is considered one of the main causes for this decline but it may also be impacted by climate change.”), Sandhill Rustic (“The moth occurs on undercliffs and upper beach so is threatened by habitat loss through factors such as erosion and in the long term by climate change”) and Northern Dart (“The upland habitat used is threatened by changing land use, overgrazing and climate change.”) However, in the case of these three species, habitat loss is also strongly implicated. While the conservation status of Lepidoptera species Ireland does not appear to be affected by climate change (except for three species), of course, this may not be the case elsewhere.
What is known for certain is that habitat has been lost and continues to be lost. Habitats can be lost arising from climate change (coastal erosion, for example) but most of our habitat loss in this part of the world has been the result of straight forward destruction by humans. This is by far the greatest threat to our butterfly and moth populations.
Habitat loss is a global crisis. This is the crisis that should be to the forefront of campaign activism. We have clear, undeniable evidence for habitat loss and its effects. The same cannot be said for certain aspects of climate change. Evidence for habitat loss in prehistory can be obtained from the fossil records, showing massive declines in tree pollen as humans cleared the land of woodland. We have little or no fully natural ancient woodland on this island. In the last 80 years, we have all but destroyed our precious, precious peatlands.
The impulse towards ravaging the few sad, degraded remnants remains virulent. Here is a recent example. Ballynafagh Bog, about 1 km west of Prosperous village in county Kildare was designated as a Special Area of Conservation under the EU Habitats’ Directive. This gives it legal protection. Looking at the bog, I find it hard to understand why this small, badly damaged site was designated as a protected site. Quite a lot of restoration work is needed given how badly damaged it is by burning, cutting (out of 160 hectares of the bog, 90 hectares has been cut) and afforestation. However, in the budget £5m was ringfenced to restore damaged peatlands. Good news for the climate, because bogs are carbon stores, good news for flood prevention because bogs hold massive quantities of water, good news for nature.
However, the government department that designated the bog, The Department of Arts, Heritage and the Gaeltacht, applied to Kildare County Council to open a new turf cutting site on Coolree Bog which is part of Ballynafagh Bog but outside the boundary line of the protected/designated zone. Kildare County Council refused permission. Determined to proceed, The Department of Arts, Heritage and the Gaeltacht appealed the decision to An Board Pleanála. The Board also refused permission mainly on the grounds of carbon emissions. The Department wanted to relocate turf cutters from Ballynafagh Bog which the state must protect, to a ‘new’ bog.
Think of the logic. The state, supposedly worried about carbon emissions and climate change, have a strategy of reducing carbon emissions by allowing turf cutting which vastly increases carbon emissions. The state, under a legal obligation to protect and restore damaged peatlands, is using peat cutting as a conservation tool. The state, whose politicians just offered a budget to address carbon emissions, will continue to push turf cutting, which destroys bogs. The state published the Red List for Irish Butterflies which describes the threats faced by the Large Heath butterfly:
The Large Heath is confined to extensive blanket bogs and raised bogs and has lost much of its habitat due to drainage, afforestation, and peat extraction. The assessment of the overall status and future prospects of its habitats is poor… A population reduction is suspected to be met in the future (>30%) based on a decline in habitat quality…
The Large Heath is rated Vulnerable on the Red List. The next step up is Endangered, a rating likely if ongoing peatland destruction continues.
In short, the state aims to reduce emissions by increasing emissions, to damage habitats and then repair them and to conserve habitats by destroying them. As for the state’s attitude to biodiversity on bogs, represented in this article by the demise of the Large Heath…
Perhaps we should be really worried about habitat destruction? Habitat removal brings climate change. This applies to the destruction of bogs, forests, natural and semi-natural grasslands and other habitat types. Such is the damage that has been and continues to be done to the habitats in our environment locally and globally that there is no catastrophising about habitat loss.
Allen, D., O’Donnell, M., Nelson, B., Tyner, A., Bond, K.G.M., Bryant, T., Crory, A., Mellon, C., O’Boyle, J., O’Donnell, E., Rolston, T., Sheppard, R., Strickland, P., Fitzpatrick, U., & Regan, E. (2016) Ireland Red List No. 9: Macro-moths (Lepidoptera). National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht, Dublin, Ireland.
O’Connell, C, Madigan, M and Farrell, P (2019) Peatland News Issue 68 Autumn 2019. Irish Peatland Conservation Council.
Regan, E.C., Nelson, B., Aldwell, B., Bertrand, C., Bond, K., Harding, J., Nash, D., Nixon, D., & Wilson, C.J. (2010) Ireland Red List No. 4 – Butterflies. National Parks and Wildlife Service, Department of the Environment, Heritage and Local Government, Ireland.
Accessed: October 13th 2019
Author: Alison Bray
Date: December 30th 2010
The fairly dramatic deluges and winds of the past two weeks have altered the landscape and butterfly scene, underlining the onset of autumn. Yesterday, Sunday, October 6th, provided a welcome break, with sunshine and light breezes.
In October one must look more assiduously for butterflies, peering at shadows cast by a high-flying insect or shading eyes against sharp autumn light to check clusters of blackberries and ivy blossom for feeding moths and butterflies.
Indeed, Ivy is a very useful plant for moths, butterflies and many other creatures. At this stage many ivy plants are in full bloom, their yellowish-green inflorescence packed with nectar. At night it is a favourite with moths; in daylight, these same moths often roost in its dense, evergreen foliage. For anyone with patience, it is often well worth checking ivy draped over a wall that had Holly Blue butterflies flying around it in August and September. Check the stalk of the flowers for slug-shaped Holly Blue caterpillars. These are feeding on the developing berry, their heads deep within the oval cup, scooping out its goodness.
While the clouds of Painted Ladies are gone, the scarlet and black Red Admiral is still about, feeding on wounded blackberries and ivy and, if it can find it, a tree leaking sap. I saw a few of these handsome butterflies yesterday but these are easily disturbed at this time of year, often flying into tree-tops when you approach one that is lower down on bramble.
Comma butterflies, still rare or absent in most areas, are nomadic in autumn and can turn up anywhere that nectar exists near woods, dense hedgerows or groves of trees. I was lucky to see one yesterday, perching briefly on a now bedraggled buddleia before gliding casually off to hide in tall willow. The Comma will sit still at other times, especially on fallen fruit or Ice Plant flowers, giving wonderful views of its deep orange-red upper surfaces and deeply scalloped wing margins.
Finally, even though most butterflies have finished flying, their caterpillars can be searched for quite profitably in areas that were heavily frequented by the adults. With this in mind, I checked Common Sorrel leaves where I had seen Small Coppers loitering in early September. After finding hatched eggs on the upper sides of some leaves, I checked the undersides and soon found some young, first instar larvae. These will feed for a time before over-wintering deep in the grassy vegetation before resuming feeding in spring.
There are some lovely moths too, especially for moth trappers who leave their light traps out in good habitat on mild nights. Beaded Chestnut, with its rich wood-coloured wings, is really abundant in early October and if you are fortunate, a Merveille du Jour may turn up to brighten any October morning when you go out to inspect your catch.
Keep on looking-autumn, the “season of mist and mellow fruitfulness” has much to offer and if one has to look harder to find it, the discoveries are all the sweeter.
September 2019 has seen some beautiful weather allowing butterflies to remain active. As I write on September 21st, Painted Lady butterflies are numerous in flower-rich areas feeding prior to their departure southwards. The continued presence in the Painted Lady is most likely due to the large-scale successive migration events and breeding, leading to a succession of Irish-born Painted Lady butterflies.
After days of concentrated feeding, Painted Ladies leave Ireland. I observed a Painted Lady at Lullybeg on September 20th engage in behaviour that I had never seen before. It had been taking nectar on Devil’s-bit Scabious in a broad sheltered track during sunny, breezy conditions with the temperature at around 21 Celsius. Quite suddenly, it flew vertically upwards at speed climbing until it disappeared from view. This may have been a migration event. Research in Britain in 2009 found that not only does the Painted Lady fly southwards from Britain and Ireland to Europe in autumn, it also migrates at altitude.
It is this high-altitude flight, out of sight of observers that for so long convinced scientists that the entire British and Irish Painted Lady populations merely died off when cold conditions (temperatures below 6 Celsius) arrived in autumn. (Incidentally, the butterfly does not die at 5 or 4 Celsius.) The behaviour I saw at Lullybeg is certainly consistent with the high altitude migration method discovered by Rebecca Nesbit at Rothamsted Research in 2009.
September has thrown up some nice surprises. Butterfly Conservation Ireland member Pat Bell has had two Comma butterflies in his lovely garden in Maynooth, in County Kildare, where the figs he grows have drawn these remarkable butterflies to stay for several days. A stunning newly emerged Comma was observed on Butterfly Conservation Ireland’s reserve at Lullybeg, County Kildare, taking nectar on Devil’s-bit Scabious. This is the first time Commas have been observed on the reserve, bringing the number of butterfly species recorded there over the past three years to 24 species. Tantalisingly, two additional species, the Holly Blue and Clouded Yellow have been seen very close to the reserve.
Clouded Yellows are being seen now-both in coastal areas (see Myrtle Parker’s records for the Cork coast for September 17th) and inland-two were seen in Lullymore on September 20th. Keep a close watch for this beautiful fast-flying and striking butterfly.
The Red Admiral, another migrant, is now appearing in good numbers. It has been greatly outnumbered by Painted Ladies this year; usually, it is the Red Admiral that is the most numerous migrant. The specimens I saw yesterday were in perfect condition, clearly just hatched. Like its more numerous relative, the Painted Lady, Red Admirals will move southwards soon.
Small Tortoiseshells are feeding eagerly too but they have other plans. They are residents; they will stick it out over our long, dull winter in its dry hibernation quarters until better times arrive in spring when it will emerge to breed. The vast bulk of the Peacock population is already in hibernation, with only the occasional individual still feeding. The Brimstone, a member of the white family of butterflies is likewise undercover now with just a small number still feeding. I saw just one, a male, on Friday, and this one fed only skittishly and abruptly roosted at 2:44 pm, in glorious sunshine.
The lovely weather of the past week, borrowed from summer, is now over. The final week of September is set to be unsettled, with rain and wind. We will most likely be saying farewell to most of our 2019 butterflies.
Now onto our autumn moths. We have some autumn moths with soft or muted ‘autumn’ colours. The Pink-barred Sallow is somewhat gaudier but its colours are soft, in tandem with the gentler and sombre colours of the autumn season. Many of these species breed on trees and some of these species are busy mating and egg-laying. Some are feeding up for winter. Like the over-wintering butterfly species, these will breed in spring.
Some moths will do so without males-the female Red-green Carpet moth will mate in autumn and hibernate until warmer weather arrives when it will lay eggs on oak, Common Blackthorn, Rowan and other trees. Male Red-green Carpets die in autumn. The Black Rustic moth looks a little sinister, rather like a cloaked grim-reaper figure. This moth breeds on Tufted Hair-grass, heathers and clovers. The Beaded Chestnut has an autumn leaf colour. Its larva feeds on herbaceous plants and when older it tackled Common Hawthorn and other trees. This species is numerous in wild gardens.
Autumn is a busy time for butterflies and moths. Keep an eye on flowering ivy over the coming weeks for late butterflies and moths. Please do not trim ivy in autumn or winter- it feeds and shelters many species. Trim it back in spring, if necessary. When cutting tall grassland vegetation in the garden, leave some patches for over-wintering insects. Finally, take care when bringing turf or logs indoors to burn over the coming weeks because butterflies often conceal themselves withing log and turf stores to pass the winter. Place any butterfly in a cool, dry space to pass the colder months in safety. Release the butterfly in spring when you see butterflies in the wild. This will typically happen later in March during warm, sunny weather.