Food Plant: Populus canescens (Grey Poplar)  

Egg: Laid on the petiole.

Mine: July - October

Notes: A gall in petiole, later mine in leaf-blade, in “green island”. Eggs may be laid on two sides of the petiole and two mines may develop (as shown). This leads to a less conspicuous green island (compared to a single mine in the leaf).

Data: 08.x.2010, Wicken, Cambs, VC29

Image:© Rob Edmunds