Brown hairstreak
Thecla betulae
Habitat
The Brown hairstreak is a rare resident butterfly in the Netherlands. This butterfly species can be found in a number of areas in Overijssel and Drenthe, along the edge of the Veluwe, on the Utrechtse Heuvelrug, in some areas in North Brabant, and in South Limburg. This butterfly species lives in areas with blackthorn thickets or plum trees. The habitat must have distinctive meeting trees, such as birch, for the mating ritual. You can spot the Brown hairstreak from late July to late September.
Appearance
Life cycle
The Brown hairstreak remains in the egg for 260 to 280 days. When the Brown hairstreak emerges from the egg, this butterfly species remains a caterpillar for 43 to 62 days. The caterpillar then pupates. Pupation lasts 20 to 38 days. After this, the Brown hairstreak lives for 30 to 60 days as a butterfly.
Host plants and nectar plants
Host plants are special plants on which butterflies, such as the Brown hairstreak, lay their eggs. When the eggs hatch, the caterpillars feed on those plants. This allows the caterpillars to grow until they are large and strong enough to transform into butterflies. Host plants are therefore essential for the survival of butterfly species, because without host plants there would be no caterpillars and ultimately no butterflies.
Each butterfly species has its own favorite plants. The Brown hairstreak uses Blackthorn (Prunus spinosa) and Prunus domestica (Prunus domestica) as host plants.
Most butterfly species, such as the Brown hairstreak, need nectar to survive. Butterflies obtain nectar from nectar plants. Nectar is a syrupy liquid that comes from flowers. This liquid contains a lot of sugar, small amounts of protein, and vitamins. Nectar provides the energy that the Brown hairstreak needs to fly.
The Brown hairstreak feeds on Eupatorium (Eupatorium), Goldenrod (Solidago), Common ivy (Hedera helix), Alder buckthorn (Frangula alnus), and Brambles (Rubus). This butterfly species also extracts honeydew from Oak (Quercus), Lime (Tilia), Birch (Betula), and Maple (Acer).
The Brown hairstreak is struggling in the wild because small-scale cultivated landscapes with their (blackthorn) hedges are disappearing. Furthermore, the aging of blackthorn thickets and the removal and pruning of blackthorn have a negative effect on the conservation of the Brown hairstreak. It is therefore recommended to prune blackthorn bushes in phases. This ensures a constant supply of young, 2- to 3-year-old wood. It is also recommended to prune the bushes once every 5 years. This is best done between the end of June and the beginning of August.
Caution with some plant species
The Blackthorn (Prunus spinosa) is a mildly toxic plant species.
The Prunus domestica (Prunus domestica) is a mildly toxic plant species, but its fruits are edible.
Eupatorium (Eupatorium) is used in natural medicine. This plant has medicinal properties for the liver, urinary tract, kidneys, bones, joints, and digestive system. If large quantities of the whole plant are ingested, it is poisonous.
Common ivy (Hedera helix) contains berries that are poisonous to humans. Ingestion of the berries causes skin rash, fever, vomiting, abdominal pain, and drowsiness.
