2019: the year of the Painted Lady?

Occasionally we experience enormous influxes of the Painted Lady, a migrant that originates in North Africa or perhaps the Middle East. We had millions reaching our shores in 2009 after a huge build up in Morocco saw a mass migration to Spain. These produced a huge generation in Spain that moved north and arrived in Britain and Ireland in late May and early June 2009. These produced a native generation in these islands that migrated south in September. 

Butterfly Conservation Ireland member John Lovatt reports on a mass migration event that has just taken place in Cyprus. It is being speculated that these came from Kuwait. The vegetation in Cyprus is currently ideal for butterfly breeding as the rains have been plentiful there this winter. Will the offspring of these Painted Ladies arrive in Ireland in early summer? Time will tell…

Painted Lady Migration from 21st March-9th April 2919 in Famagusta “county”, Greek Cyprus

I have repeated a visit to the same Gkreko district in Famagusta for the past seven years in March/April to observe bird migration.

This year I witnessed an unprecedented large migration of Painted Lady butterflies. There were small numbers seen daily from 17th March which would be the norm at this time of year.

On 21st March there was an invasion of Painted Ladies which one might liken to what might be expected with locusts. Clouds of butterflies arrived constantly all day. There were around 100 butterflies in front of me and the same number on both sides and behind me. To look beyond, the same numbers were everywhere as far as I could observe. I estimated at least a million on the Gkreko Head district and when at Paralimni about eight km. distant, there was a similar migration. I later learned at Nicosia there were unprecedented numbers there. This information came from a well-respected bird watcher.  I later heard there were large numbers at Pafos, a two-hour drive away to the west.  It must be reasonable to consider the large numbers were present all along the south coast and into the Turkish south coast on the panhandle to the east.

It was considered five million butterflies in the whole Famagusta district to Nicosia would be a conservative estimate. This would only be section of the whole migration along all the coast.

Numbers continue to arrive but in much lower numbers of 30/300k daily up to the 8th April. On the 8th April there was another large invasion, but not like the 21st March, with perhaps a million estimated in the Gkreko district.

There were a few Painted Lady butterflies observed which were about two thirds the size of the usual ones observed.

There was a large dragonfly migration at the same time, but nothing like the butterfly numbers. Clouded Yellow butterflies were also present, but perhaps ten to 20 seen daily.

In all, it has been a remarkable experience that has amazed the population of Cyprus, not simply nature lovers.

Painted Lady. © J.Harding.

 

 

Lullybeg Reserve Update

A sharp easterly wind is keeping the butterflies grounded on Lullybeg Butterfly Reserve in Lullybeg, County Kildare. So far in 2019, we have spotted Brimstones, Small Tortoiseshells and Peacocks.

We await Orange-tips, Green-veined Whites, Speckled Woods and Common Heath moths which we expect at this time of year. All we need now is good weather.

There has been an extensive management programme undertaken since last summer and the results are very keenly awaited. Grazing on part of the northern section, mechanical removal of very dense scrub to extend high-quality grassland habitat and manual removal of scrub on an area on the southern side of the reserve by our members has really extended opportunities for the reserve’s butterflies and moths.

We can report that the Marsh Fritillary is really thriving. Over forty nests (many containing hundreds of larvae) survived the winter and many, if not all the caterpillars are now in their fifth or even sixth instar growth stage (there are six instar stages in this species’ larvae). Over the next three weeks, healthy larvae will enter the sixth instar followed by pupation. Fingers crossed we will see outstanding numbers of this gorgeous butterfly darting around in late May and during June.

A nice surprise is the re-discovery on the reserve of the beautiful day-flying Wood Tiger moth. A larva was seen on a Devil’s-bit Scabious leaf (see below). This moth is rated Near Threatened on the Moth Red List (Ireland Red List No. 9 Macro-moths (Lepidoptera)). This record may be the first county record for Kildare, although the larva was found on the reserve about five years ago. The larva seen on April 13th was in a newly cleared area, so we are hopeful that it will increase here.

Other scarce moths found on the reserve are the Small Purple-barred, also Near Threatened. This species has a strong population at Lullybeg. This attractive day-flyer is usually found on unimproved calcareous grassland, limestone pavement and heath, but here it is, on cutover bog! We also have Narrow-bordered Five-spot Burnet moth, ranked Vulnerable on the Moth List.

Over the coming months, a close watch on all of these species will be kept. We hope our efforts to maintain the special habitats here will meet the needs of the rare moths and butterflies that rely on the habitats at Lullybeg, as well as the more widespread species.

Wood Tiger larva on Lullybeg Reserve.© J.Harding.
Narrow-bordered Five-spot Burnet Moth, ranked vulnerable, resides at Lullybeg. © J. Harding.
The cleared area used for breeding by the Wood Tiger moth.© J.Harding.
This area cleared of very dense scrub, is used by the Small Purple-barred moth, rated Near Threatened on the Red List for Ireland’s larger moths. © J.Harding.

Larval Survival Strategies

The butterfly larval stage is the growth stage for butterflies and moths. It is a highly sensitive stage highly vulnerable to disease, starvation, predation, infection by parasites and failure to thrive if environmental conditions turn hostile.

According to Newland et al. (2015) many adult butterflies live long enough to lay about 50 eggs. Of these, 20-40 might become caterpillars of which perhaps 10 will become chrysalises. Just 1-3 adults will be produced.

In these calculations, the highest numerical loss is seen in the larval stage. What do larvae do to avoid being eaten?

There are essentially two phenotypes (concerning the appearance of an organism arising from the relationship of its genetic makeup with the nature of its environment) used by Ireland’s butterfly larvae.

Some butterfly larvae are aposematic. This means that larvae are highly visible to send a warning signal that they are distasteful, toxic or painful to eat.

Such larvae do not attempt to hide or blend in with surroundings. These larvae feed openly, often in groups, unconcerned about an attack by birds. The larvae of the Large White, which are brashly obvious, are black, white and yellow. These are smooth-skinned but their bodies contain caustic mustard oils that will burn the mouth of a predator.

There are other aposematic larvae that are highly distasteful and painful to eat. The Marsh Fritillary larvae feed openly, in large groups until their final growth stages. The larvae are spiky, containing bristles and black, standing out when they bask on pale, dry leaf litter. The bristles are highly injurious. If you don’t believe me, try pressing one to your lips. Even doing so gently is quite unpleasant. If a bird does grab a spiky Marsh Fritillary, Peacock or Small Tortoiseshell larva, there is a chemical deterrent deployed which involves the larva placing its mouthparts against the bird’s beak and vomiting. The vile liquid (I’ve smelt it but not tasted it-yet!) provokes the bird to drop its prey.

If that is not enough, the larva also pushes its spines into the predator, causing it to recoil in pain and drop the larva.

Most of these larvae are quite unharmed when dropped and roll into a ball to present a forest of spikes in the event of another attempt on its life.

Marsh Fritillary larvae spines and distastefulness mean that it is almost immune to avian attack. © J.Harding.

The larvae of other species are cryptic and rely on blending into their surroundings. These larvae are soft-skinned and edible, highly attractive to birds. Their colour often matches the food plant. Their behaviour is usually highly secretive.

One example of such a larva is the Purple Hairstreak. This species feeds on oak leaves and flowers. The egg hatches in March and April when the oak buds begin to open. The tiny larva enters the opening buds but when older and the leaves unfurl it must feed openly. During the day it rests at the base on the leaves, on leaf scales which it closely resembles in colour and patterning. In order to continue to blend in with the scales, it spins a loose web around these in case they are shed by the tree, ensuring these are retained.

Feeding is now carried out at night when birds are inactive. Another strategy is its remarkably slow movement which avoids drawing attention. When oak leaves are unfurling, small birds scour the trees in search of the myriad larvae that feed on oak leaves. While Purple Hairstreak larvae resting at the base of the leaves are found, the research suggests that about half of the larvae survive on oak leaves with predation greatly increasing after leaving the tree to pupate (Thomas 2010).

Another strategy used by the larva of the Purple Hairstreak is to play dead if disturbed by a bird. If it is picked up, the larva stays still. A wriggling larva is a clear confirmation that live protein has been found, while a still creature might be a leaf scale or piece of bark.

Purple Hairstreak fourth instar larva on leaf scales. © J.Harding.

While the strategies described may protect some caterpillars from birds there are many other hazards. Many caterpillars are killed by bad weather, viruses, parasitoids and other predatorial animals, such as wasps.

When you see the perfect adult butterfly admire it not just for its beauty but for its achievement in getting this far!

References

Thomas, J. and Lewington, R. (2010) The Butterflies of Britain and Ireland. (Revised edition) British Wildlife Publishing, Dorset.

Newland, D., Still, R., Swash, A. and Tomlinson, D. (2015) Britain’s Butterflies (Third edition) Princeton University Press, New Jersey.

 

An Bord Pleanála refuses permission for Waterways Ireland ‘Blueway’

An Bord Pleanála has rejected Waterways Ireland’s appeal against the refusal by three local authorities of its application for the installation of hard surfaces along the River Barrow for all of County Carlow and part of County Laois and County Kildare.

This issue, which has created well-coordinated opposition by various groups supporting the continuation of the current grassy towpath and gentle management to preserve the relaxed character of the river and track and its associated wildlife has highlighted the unnecessary intrusion and destructiveness of some of Waterways Ireland’s actions.

It also highlights the body’s lack of commitment to biodiversity in its rush to exploit natural resources to turn a tourist profit. The decision also suggests a lack of realism and one wonders how wisely money was spent in pursuing this agenda.

On a related note, the National Parks and Wildlife Service (NPWS) has replied to our query concerning Waterways Ireland’s tree-felling along the Barrow.  The National Parks and Wildlife Service has told us that Waterways Ireland did not, as they should have done, consult NPWS concerning the tree-felling works carried out.  The reply from NPWS made it clear that Waterways Ireland did not check if a screening assessment for the tree-felling was required. Because this screening assessment was not done, it is not possible to say if the tree-felling needed ministerial consent or whether planning consent was needed.

It will be interesting to see if any action is taken by NPWS or Waterways Ireland to attempt to restore the habitat. Trees should be planted to replace those removed.

It is, unfortunately, quite disheartening that Waterways Ireland, a public body, cannot be trusted to follow the procedures laid down in the EU (Birds and Natural Habitats)Regulations 2011 and the parent Birds’ and Habitats’ Directives. Conservation bodies will need to remain vigilant.

Finally, congratulations and thanks to everyone who contributed to the campaign to protect the Barrow.