I found these first on Blackthorn when looking for leafminers but couldn’t find any examples on the British Leafminers website, so I posted photos on Twitter and asked my ecologically minded followers ‘what’s this?’.

The response was almost instant: ‘Carcina quercana does that on several trees. The silk tube is always against the midrib or a vein and they venture out to graze from there’.

Carcina quercana is a lovely little moth and the little silken tubes are created by its larvae. The UK Moths website says ‘The foodplants are various deciduous trees, including oak (Quercus) [hence the quercana, in its name] and beech (Fagus)’, but, as my examples here show, the larvae don’t seem too fussy about what they eat. My photos here, showing both the upper and lower sides of the leaves, are on Blackthorn, Bramble, and Buckthorn.

And why did I not find this species on the British Leafminers website? Well, strictly speaking, it’s not a miner – the larvae graze on the underside of the leaf when they venture out from their protective silken homes. You might just be able to spot the larva in the photo below.