Please kindly help - I have a lovely lemon tree, she is 3 years old now and has suddenly developed a problem with the leaves.

The leaves on the top half of the tree have strange marks on them, as though a slug or worm have crossed the leaf. The marks meander across the top of the leaf, they then turn brown and curl up and fall off the branch, this tree has also never borne any fruit - please advise the right approach to cure it.

ps I live in Dubai and the weather here is pretty hot all year especially May - September where it reaches 45 degrees and the lemon tree receives the full afternoon sun.

Kind regards

Bianca