It's a leaf miner of some sort. Four insect orders have members with larvae that specialise in feeding on the tissue inside leaves, Flies (Diptera), Moths and Butterflies (Lepidoptera), Sawflies (Hymenoptera) and Beetles (Coleoptera). The commonest are Flies and Moths.

Thats leaf minor. You need to remove all the leaves im afraid as the bug is inside. You spray with somethings - sorry I cant remember what. But Bamboo will know or someone else

Just checked and this one is a Dipteran (Fly).

So it's a baddy? But if I remove all the leaves won't the plant suffer? Thanks Fractal & Great ... you were quick! :O)

Cut them back and liquid feed. You should get another flush of growth with late flowers. Hopefully, this will also be outside the active period for the little fly that causes it.

Right thanks ... will do.

Uncle Fractal will keep you right.....lol

:o))

Lol