The citrus leafminer damage is often misdiagnosed as a disease problem.

CURLED LEAVES ON CITRUS
For curled leaves on citrus this is the cause: This will not kill your citrus. It is caused by the Citrus leaf miner. Leafminers are tiny caterpillers which is the larval stage of the Citrus Leafminer Moth. The larvae bore into the leaf shortly after hatching and live inside the leaf for only 3-4 weeks. After emerging, they oftentimes will curl the leaf and live inside the curled leaf until molting into a moth. The moth is usually actively laying eggs in the warmer time of the year starting in about June but can start earlier. This damage WILL NOT KILL your citrus plant but will make it very ugly. The moth will lay its eggs on tender emerging leaves when the tissue is very soft and easy to enter. To keep your plants clean you must spray on a bi-weekly basis directing the spray to the new growth. It is recommended that two different sprays be alternated.