Food Plant: Sonchus arvensis (Corn Sow-thistle), S.oleraceus (Smooth Sow-thistle), S.asper (Rough Sow-thistle)

Mine: Summer, Autumn

Notes: Forms a circular pustule in the leaf, around 5mm in diameter (the pustules shown measure 4mm in the centre with a width of 6mm overall). The pustule is equally considered a leaf mine, as well as a gall and turns purple due to accumulations of anthocyanin, induced by the larva. The lower surface of the pustule is slightly concave and a pale yellow or orange larva (or pupa) may be found beneath. The adult emerges through the lower surface in the autumn. Mine shown on S.arvensis

Data: 16.viii.2015, Downham Market, Norfolk, VC28

Image:© Rob Edmunds