Spray the foliage with a strong, stiff jet of water when a noticeable amount of dust accumulates during the growing season. Accumulated dust is detrimental to beneficial insects that get rid of pests. A forceful spray of water removes existing pests.
Wrap a 4-inch wide band of copper wire around the base of the tree trunk. Copper wire will deter garden snails. Wrap the wire tight enough that snails do not creep underneath but not so tight that it cuts into the bark. Check the wire once a month to make sure it does not get too tight around a growing trunk.
Prune low-hanging branches touching the ground or other structures flush with the collar in winter or early spring. Ants, which are harmful to beneficial insects, may climb low-hanging branches. Keep the bottom 10 to 12 inches of the tree trunk clear of sprouts to prevent attracting citrus leafminer.
Wrap a strip of heavy paper around the tree trunk. Apply a sticky insect barrier on the paper. Check the insect barrier occasionally to see if it needs replacing. Sticky insect barriers help prevent ants from climbing up the tree trunk.
Spray horticultural oil to a new flush of leaves, when they are about 1/2 to 1 inch long. Horticultural oils differ, so read the product label for the correct strength and timing. On average, the best time to spray horticultural oil is on a cool, cloudy morning. Horticultural oil will protect the tree from citrus leaf miner and suffocate any pests.