2009 Donegal Painted Lady Migration 1

Donegal was one of the Irish counties to be most favoured by the arrival of huge numbers of Painted Ladies on May 31 and June 01.

On May 31 for example at Rossnowlagh (G86) Frank Smyth estimated PLs heading north in a narrow corridor at 80 per hour. While further north at Slieve League (G57) Robert and Hannah Northridge estimated PLs passing at 40 per mimute.

On June 02 at St Johnís Point (G76) Ralph and Liz Sheppard saw thousands and reckoned there were at least 20,000 PLs spread out over an area of about 100 ha. On June 10 I visited St Johns Point in fine weather and there were still thousands of PLs to be seen there.

As of June 20, PLs have been reported from all parts of the county, usually in handfuls but at the start of the month often in dozens and sometimes in hundreds.

One spectacular feature reported by three different people in very similar terms has been of massive localised communal egg laying. This has consisted in a few hundred PLs landing in a field with many young creeping thistles and spending some hours laying in such abundance that the thistles were coated in eggs.
In all three cases the egg laying was concentrated in a limited area of the field of some ten metres2. This was despite the fact that thistles were available over much wider areas of the fields but which remained untouched.
The first event was recorded on June 01 by Boyd Bryce at Inch Island (C32) in Lough Swilly.

On June 02 Frank and Joan Smyth observed a similar occurrence at Carrickfad (G86) on the south side of Donegal Bay. Subsequently FS examined three leaves on a single thistle and counted 316 eggs. While this may have been exceptional clearly many tens of thousands of eggs were being laid in each location.

On June 03 Danny Gillespie saw hundreds of PLs laying in a field at Muckros (G67) on the north side of Donegal Bay.

I saw the Inch Island site on June 06 and the Muckros site on June 12. In both cases some dozens of PLs were still present. I have had egg samples from all three sites taken at the time of my visit to two of the sites and all have appeared to be hatching successfully despite cold northerly winds a few days after the laying. In the cases of Inch Island and Muckros it is proposed to delay cutting the thistles and observe the outcome.

Bob Aldwell