As part of the Species on the Edge programme along the East Coast, Butterfly Conservation has been involved with work to help reverse the declining fortunes of seven different coastal species. Alongside Small Blue and Northern Brown Argus our work has also focused on another insect, the tiny Bordered Brown Lacewing. In the UK this particular lacewing is only found along the East Coast of Scotland.
July 2025 marked 200 years since the Bordered Brown Lacewing was first recorded in the UK by renowned entomologist James Charles Dale, so as part of the Species on the Edge programme we are asking volunteers to help us reach 200 hours of surveying for the lacewing.
The Bordered Brown Lacewing is tiny, measuring just 1cm in length, and is proving rather hard to find outwith it’s stronghold of the steep coastal systems south of Aberdeen and Holyrood Park, Edinburgh.
Currently there is only one recorded sighting of the Bordered Brown Lacewing in the Highland area, this was just south of Helmsdale (by Nick Littlewood). Following some site visits with Buglife and discussion with Nick, we have identified stretches of the Black Isle and Easter Ross peninsulas as having potentially good habitat for the lacewing.
Key Facts
- Up to 1cm long
- Adults can be found from June to August
- Associated with Wood Sage, this lacewing eats aphids and other insects that are on the sage
- Eggs are laid individually on the underside of leaves
- Overwinters in a cocoon
- Prefer Wood Sage growing on rocky exposed slopes
- Threatened by habitat loss, particularly scrub encroachment
- Recognised as in need of conservation action on the Scottish Biodiversity List
How to survey for the Bordered Brown Lacewing
The two main ways to survey for the lacewing are either to use sweep netting or beating the vegetation:
- Sweeping: Sweep a large insect net over suitable looking vegetation and see what you have managed to scoop up
- Beating: as the name suggest take a stick (or similar) and while holding a shallow basin or bucket under the Wood Sage, beat it catching whatever insects fall out. A little trial and error is required to get the amount of force required correct. Too light and you won’t dislodge the lacewing, but too hard and you may break the Wood Sage.
We have found that any lacewings dislodged from the vegetation do usually sit still for a little before flying off, giving you plenty of time to scoop them into an insect pot. Once they settle down you can then take pictures and videos to aid with identification.
How to identify the Bordered Brown Lacewing
Generally this lacewing has something of a hunched shoulder look about it, but to identify it from other brown lacewings requires some technical knowledge of the wing veins.
The Bordered Brown Lacewing has a wing pattern quite distinct from other lacewings. There is a wide costal space on both forewings (between the outer edge of the wing and the humeral vein that runs along the length of the wing). This can be seen with the naked eye, but it is easier to see with a hand lens or small hand held magnifying glass. It also has at least five (sometimes six or seven) veins that branch off from this humeral vein.
Recording: either via iRecord or if you would like to provide Species on the Edge with some supplementary information from your survey, such as habitat conditions, please request a Species on the Edge survey form from Tracy Munro tmunro@butterfly-conservation.org