The brown hairstreak was spotted south of Dendermonde in recent years, in Opwijk and Herdersem (Aalst), but now experts also came across eggs of the brown hairstreak in Buggenhout and Wieze.
The increased numbers are unexpected because butterflies are having an increasingly hard time in many parts of Flanders.
“Food is needed for the caterpillars. By planting new blackthorn hedgerows especially favoured by brown hairstreaks the butterfly is finding more locations in which to lay its eggs” says Ruben Meert of environmental organisation Natuurpunt.
The blackthorn or sloe is popular among people with a heart for nature because the plant offers a home for many inspects and animals: “The plant provides a good supply of food. When new nature areas are purchased conservationists will think of planting blackthorns. If these efforts can be kept up, we hope to see the butterfly appear in many more areas.”
The brown hairstreak does not seek the limelight. It isn’t all that large and doesn’t head for flowers.
“There are butterflies with powerful wings that can even cross the North Sea. The brown hairstreak can’t do that. It stays close to home and remains close to where it was born. It doesn’t cross large meadows or colonise new areas” says Ruben.
He warns against unwarranted optimism: “Just because the brown hairstreak is back it doesn’t mean all problems are sorted. The wolf and the beaver are doing well too, but for every species that is doing well there are dozens of others that are having an extremely hard time.”