Asian Citrus Psyllid

• The Asian citrus psyllid, also known as the citrus leafminer, is drawn to lime trees and is a tiny fly maggot that causes squiggly lines on the leaves, as well as leaf crinkling and cupping. Often seen on new growth but not much of a threat to the tree, leafminers can be treated with a horticultural oil or dish soap solution that consists of 3 tbsp. dish soap for every 1 gallon of water.
  
  

Aphids

• Aphids, which are tiny insects that can also be controlled with water sprays or detergent solutions, populate lime trees and cause cosmetic damage only. Symptoms of aphid infestation include curled or cupped leaves, leaf distortion and a sticky substance on the leaves.
  
  

Thrips

• Flea-like and tiny, thrips can cause yellow streaking and distortion on your lime tree's leaves, but control is unnecessary.
  
  

Grasshoppers and Caterpillars

• Both grasshoppers and caterpillars are fond of lime trees and may cause minor aesthetic damage by chewing, cutting or tearing your tree's leaves. Damage is minor, but caterpillars can be hand-picked or treated with Bt, or Bacillus thuringiensis, in large outbreaks.