I purchased a potted Meyer lemon tree two months ago from Home Depot, Toronto. The tree had no health issues until a fortnight ago, Now, its leaves have developed light patches, some lower ones have turned brown on edges and fallen off. Over watering doesn't seem to be the case. I did put half a spike of citrus fertilizer in the pot 2 weeks ago. I also noticed a few baby spiders on the tree when it was sitting outside( not the red spider mites) which I removed and there haven't been any more since then. I don't see any other signs of insect infestation on the leaves. I am attaching a few pictures of the leaves to give you a better idea. Any suggestions will be highly appreciated.