Amazingly, I didn’t see my first Marbled white (Melanargia galathea) of the year during my recent week on the south coast of Dorset, nor during any other recent jaunts away from home. Though this butterfly species is not resident locally, my first sighting this year was on 29 June just a couple of miles from home at Lavernock Nature Reserve. Even more surprisingly, I didn’t see just one, but rather two of these stunning butterflies, and a couple of local chaps I talked to had seen six (!) the previous day. As we had just experienced our second heatwave of the year, from the 22nd to the 25th of June, it’s likely that these butterflies had been blown across the Bristol Channel from England on the hot nor’easterly winds we experienced during those few days.

I love these stunningly patterned butterflies so I was very pleased to have timed my latest visit to Weymouth and the Isle of Portland with their peak flying time of mid June to mid July. Despite my visit also coinciding with our third heatwave of the year (I’d booked my travel several months earlier), by leaving my guesthouse before 7am, I still managed to spend many hours over several days wandering around the disused quarries on Portland, thrilled to be surrounded by these, and many other, butterfly species.

In his Life Cycles of British & Irish Butterflies, Peter Eeles explains that the aposematic colouring of this black-and-white butterfly is thought to deter potential predators, the flavonoids from the food ingested by its larva making both larva and adult taste bad. Eeles also notes that these flavonoids ‘make the butterfly more visible to potential to potential mates thanks to the ultra-violet reflection from the flavonoid-rich white areas that contrast with the blacks on the wings’. Wouldn’t it be amazing to see what the butterflies see?

If you’re wondering why the Marbled whites in some of my photos have a brown hue that’s because the female of the species, though still having the black-and-white marbling on her upper wings, exhibits a pale brown tint on the undersides and on the leading edge of her forewings.