By Irshadj
United Kingdom 
This attached photo is a leaf from a eureka lemon tree that I recently purchased from an online store. Also have a navelina orange tree with exactly the same problem.
Initially one or two leaves had this but this has now spread to most/all of the leaves.
Have looked at various times (day/night) and not been able to see any bug that is doing this
I have tried spraying soapy water and Bayer Provado ultimate bug killer and this does not seem to have helped (2-3 weeks).
Does anyone have any idea what this could be and how to resolve ?
Thanks
4 Apr, 2012
Answers
No, no new growth. Got them around 3-4 weeks ago.
Initially had them indoors but started to leave them out since we started having that great weather outside (early last week)
I do cover them with fleece covers on the cooler nights (based in greater london area).
4 Apr, 2012
It looks like nothing so much as physical damage - I don't know how well they were packed, but perhaps the leaves were bent or damaged in transit, and these brown scars are where that happened. If it continues, or in fact, now, you could contact the supplier and get replacements.
4 Apr, 2012
Not sure about the physical damage as initially one or two leaves had it and since then other leaves started with the same marks. Some leaves then had additional marks as the days went one. Almost entire tree now has these marks.
Totally confused by this as internet searching shows nothing like this. The closest was citrus leaf miner but the pattern is wrong for this.
Thank you for the interest and trying to help.
4 Apr, 2012
Exactly, it doesn't point to any known problem with citrus - and it looks remarkably like physical damage of some kind. I'd return them.
4 Apr, 2012
If you've had any new growth since you got them, are these markings appearing on those as well? When did you get them? Where are you keeping them at the moment?
4 Apr, 2012