Thecla betulae

Brown Hairstreak


by Matt Rowlings

copyright © 2003-2024

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Valais, Switzerland, August 2013


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Valais, Switzerland, August 2014


Field notes and information

A creature of hedgrows and treetops. Photography is difficult due to this behaviour. It is discrete and easily overlooked although can be found feeding on flowers - always a surprise, and a very welcome one!

Identification & Similar species: Distinctive and without similar species.

Distribution & Flight: Widespread but local and absent from parts of the range. Usually uncommon and hard to find so is surely under recorded. Surveys of the species tend to focus on the eggs which are much easier to find than the elusive adulds. The round white eggs are easy to locate on the food plant in the winter. Adults fly from mid July until end October, but the peak is generally in August or September depending on locality.

Habitat & Behaviour: It flies along woodland edges and hedgrows. Males rarely come low down although females may be found feeding on flowers and egg laying between about 1 and 2 m above ground level. Males congregate around master trees, usually tall ash trees - I've only seen this once, and it wasn't infact on ash, more a lose congragation of several adults along a woodland edge centered around several different trees, includinging conifers!

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Valais, Switzerland, August 2014

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Valais, Switzerland, August 2014

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Vaud, Switzerland, March 2010

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Vaud, Switzerland, September 2020

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Valais, Switzerland, August 2013


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Valais, Switzerland, August 2014


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Vaud, Switzerland, September 2020

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Vaud, Switzerland, March 2010