8th August - Long-tailed Blue - Portsdown Hill, Hampshire

Back in October 2023, there was a small colony of Long-tailed Blue butterflies on Portsdown Hill, over the last three years the site has been checked but they were not found.  This week though at the same time the report of the Queen of Spain came out a Long-tailed Blue was found in the very same spot.

After the success with the fritillary we decided to head south to get another rare migrant of the UK.  After an hours drive we arrived at the car park, had lunch ten crossed the road to the spot with the bench.  The sun was in and out with some cloud about and as we arrived it went in and a butterfly buzzed around and then settled once the sun was behind the clouds.  A close look and there was the Long-tailed Blue.

The Long-tailed Blue is an extremely rare migrant to the British Isles.  The most noticeable influx occurred in 2013 when Long-tailed Blue were seen at 9 sites in Devon, Hampshire, Sussex, Kent and Suffolk. Mating pairs, eggs and larvae were also found, confirming that the species had successfully bred and, on 8th September 2013, the first of the offspring emerged in Wiltshire and Kent. Sightings from other counties followed, with sightings continuing into October.

The adult butterfly has a jerky and rapid flight that is very similar to a hairstreak, but flies closer to the ground. It is also a strong flyer, borne out by its ability to migrate over large expanses of land and water. This butterfly possesses a pair of "tails" that give this species its name, together with an eye spot where the tails meet the wings. These act to divert a predator, such as a bird, away from the essential body parts. When at rest, the butterfly will rotate the hindwings which causes the tails to move, diverting predators from the more-important parts of the body.

This was a female, with the brown upper wing, the males being a graduated blue.

On the continent, this butterfly is considered a pest of pea crops, one of the larval foodplants, where it can cause considerable damage. This butterfly is continuously-brooded on the continent but again like the Queen of Spain is unable to survive our winters, who knows.

The white stripe on the hindwing looks a little faded which suggests these are migrants.  Who knows what has attracted them to the exact same spot as last time three years ago.  The chances are that now these will breed and that there will be a second brood in October.

They can quite feisty and will chase off butterflies much larger than themselves.

When the sun was out at least two were flying around the area, but as soon as it went behind the clouds they settles on the grass stems.

Alo in the area were a Small White.

And of course a Painted Lady.

We decided to go back and try and find the Brown Hairstreak, but once again the search was fruitless.  Quite bizarre we had seen two extremely rare butterflies in the UK today but could not get to see an endemic!

However there was always the Swallows once again flying around the cropped grass.

And a confiding Holly Blue where the Brown Hairstreak should have been.

Some lovely cloud formations looking south from the bottom of the slope, again looking impressive in black and white.

I doubt there are many days when you get to see two rare migrant butterflies in the United Kingdom, so it was special.  Who knows maybe as our climate changes we will see more of these exotic butterflies reaching our shores