Leaf burn has many different causes. One of which is sometimes pests as they could infect the plant.
It looks like it might be one of the list below.
Environmental leaf burn
Too hot / too dry
Bacterial leaf burn
Reaccuring every year
Too much/too little fertiliser
usually iron or manganese
It is responding a stressor, like not having enough light. Less light is the trigger for trees to loose their leaves in the fall. Those leaves change colour, because the plant cut off liquid to leaf. As the leaf stop making energy it shows it real colour. The colour it has without photosynthesis.
Your plant should be at your brightest window and have a ...