Like any other tree, the lemon tree is susceptible to its share of pests. Fortunately, only a few bugs present an issue for lemon trees, and their impact is usually not detrimental. Some bugs can be present year-round, while others are only present in the spring and summer. In order to properly treat these bugs, take the steps to understand their activity.
The most common bugs that affect lemon trees include the Asian citrus leaf miner, citrus whitefly and brown soft scale.
After feeding on a lemon tree, the Asian citrus leaf miner leaves an unmistakable trail, much like that of a serpent, under the surface of a tree's leaves. In time, the trails turn a shade of gray and their feeding also causes leaves to become seriously distorted. The citrus whitefly also lingers on the underside of a lemon tree's leaves. It lays its eggs there, feeds on the sap within the leaves and then covers them with a sticky, sooty honey dew that causes the leaves to curl. Brown soft scales also suck the sap from lemon trees and cause the leaves to become discolored and drop.
Horticultural oil can prove effective at treating both the Asian citrus leaf miner and brown soft scale. Insecticidal sprays can treat the citrus whitefly effectively, but gardeners should take precaution to use a spray specified for fruit trees.
The Asian citrus leaf miner measures about an inch long but is best and most easily identified by its activity on a lemon tree. The citrus whitefly is a small, white, winged insect that only reaches about 1/12 inch. Brown soft scales are small insects that do not move and attach themselves to the foliage and wood of a citrus tree.
Watch your lemon tree closely---especially young trees. Because pests such as the Asian citrus leaf miner attack new growth on young trees, take steps to monitor the tree's leaves from early on. For the most important and effective measure to prevent an infestation of pests, keep your lemon tree properly watered and fertilized.