11 Saturday Apr 2020
Another new butterfly species for the year, the Holly blue!
This individual is actually the second one I’ve seen – the first was up and over the bushes and trees too quickly for me to grab a photo but this little lovely was flying slowly from spot to spot along a grassy slope so I was able to enjoy its beauty and get a couple of images. There’s just something very special about blue butterflies and the Holly blue is usually the first of the year to emerge.
23 Tuesday Jul 2019
Posted in 365DaysWildin2019, insects, nature
Tags
#365DaysWild, British butterflies, butterfly, Holly blue, Holly blue butterfly, Lavernock Nature Reserve, summer butterflies
The Holly blue is one of several British butterflies that goes through more than one life cycle per year (you can read more about them here), and the second generation of these stunning little butterflies is now on the wing in my local reserves and wild places.
I saw my first of the summer brood on 14 July at Grangemoor Park, and this perfect little female was feeding on bramble flowers when I visited Lavernock Nature Reserve on Saturday, 20 July. Look out for them on ivy bushes, as that’s where the second generation females lay their eggs.
15 Monday Apr 2019
Posted in 365DaysWildin2019, insects, nature, spring
Tags
#365DaysWild, British butterflies, butterflies, butterfly, Holly blue, Holly blue butterfly, Lavernock Nature Reserve
I walked almost every path, track and trail at Lavernock Nature Reserve today hoping that, in spite of the strong cold southerly wind blowing in off the sea, I might find some butterflies in the more sheltered spots … and I did – four Speckled woods, a fine male Orange-tip, and the one butterfly I had hoped most to see, my first Holly blue and my tenth butterfly species for 2019. And what a beauty it was!
22 Wednesday Aug 2018
Tags
British butterflies, butterflies, butterfly, Celastrina argiolus, Holly blue, Holly blue butterfly
I blogged about the Holly blue butterfly (Celastrina argiolus) back in May but I’ve since read some really interesting info about this lovely little butterfly and have some new photos to share as well.
My information comes from the book I’m currently reading, which I highly recommend – it’s Wonderland: A year of Britain’s wildlife day by day by Brett Westwood and Stephen Moss. The entry from 13 August is about the Holly blue and answered a query I had about why I’ve recently been seeing so many Holly blues on Ivy plants rather than on Holly.
It turns out the Holly blue has two generations per year: as their name suggests, the females from the first generation lay their eggs on Holly plants and that’s what the first generation of caterpillars munch on. Then, once those caterpillars have pupated, they emerge as butterflies from around mid July, and the females from that second generation lay their eggs on Ivy, as that’s what the second generation caterpillars eat.
I’ve also been wondering why I seem to be seeing so many more Holly blues this year and Wonderland has the answer to that too:
These fluctuations [in population], over a cycle of five or six years or so, are caused by a small parasitic wasp called Listrodomus, which injects the caterpillars with a long sting-like ovipositor. The Listrodomus grub lives inside the caterpillar, but keeps it alive long enough to allow it to pupate, emerging later from the chrysalis. As wasp populations increase, they reduce the Holly blues. Fewer butterflies mean fewer opportunities for the wasps and so, in turn, wasp numbers fall too. This allows the butterflies to build up again, and that’s why over a span of several years our sightings of Holly blues go up and down.
20 Sunday May 2018
Tags
blue butterfly, British butterflies, butterflies, Holly blue, Holly blue butterfly, Lavernock Nature Reserve
With clear blue skies and temps in the mid 20s, it was hot work chasing the Holly blue butterflies (Celastrina argiolus) around Lavernock last Monday. I think I saw five but they move so quickly along the scrub and up and over the trees that it was hard to be sure. Those fast fliers are mostly the males, I think, constantly sniffing for the female pheromones.
I know there were at least two Holly blues, as I managed to get a male and female together in one photo, and then was lucky enough to catch the female laying an egg on a Dogwood plant. Once she’d departed I carefully examined the plant but couldn’t find the egg. I think she must have tucked it well in amongst the flower buds, which I didn’t pry apart in case I damaged the newly laid egg. But I remember where it was so will try and go back in a week or so to check for a caterpillar.
Holly blues are the first of Britain’s blue-coloured butterflies to emerge each year, which is one way to distinguish them from the many other blue butterflies. Another is their flight pattern – the other blues usually fly close to the ground. And the Holly blues are the only ones with small black dots on the undersides of their wings though, unless you see one perched, you’ll need to be quick to spot those dots ’cause these little beauties are speedy.
