The Common Brimstone (Gonepteryx rhamni) is one of the earliest butterflies to show up in spring and one of the latest to be spotted in autumn. Adult butterflies can reach a lifetime of almost a year which quite an achievement in the world of butterflies.
In about two months from now the Common Brimstone will be flying again in Finland. Right now, the butterflies overwinter between fallen leafs and growth under a layer of snow. In many languages this species is named “Lemon Butterfly” (ger. Zitronenfalter, fin. sitruunaperhonen) due to its color. Nevertheless, it’s mainly the male which are colored in a strong yellow. Females have a rather pale shade and almost appear to be white (see photo below).
As for many other species in Finland, the year 2014 has been harsh. Despite of flying in large quantities during spring it was only a couple individuals of the Common Brimstone that I spotted in summer (summer generation). Even though it’s such a common species it’s always a pleasure to sight this butterfly. Here’s a couple of photos from the year 2014. The same year I also had the chance to follow a dalliance of a male and female.
Even though the Brimstone is such a common butterfly finding caterpillars is often a bit tricky. The reason is that caterpillars only feed on alder buckthorn (Rhamnus frangula). This plant is not rare either, but it may be growing well hidden in the woods. Hence, the challenge is not to find caterpillars, but the foodplant first. Here’s some snapshots from season 2014. I also had large losses due to paratites this year. Most of the caterpillars I took home for raising never reached the pupal stage.