Preventive Care

• Provide consistent care to your liquid ambar trees as vigorous plants have a better ability to avoid and recover from pest problems than unhealthy, weakened trees. Grow liquid ambar trees in areas of your home landscape that offer full sun exposure for optimal growth and color. Maintain moist, well-drained soil with a pH no greater than 7. Liquid ambar tolerates wet sites and wind, but will not tolerate alkaline conditions. Grow these trees in United States Department of Agriculture hardiness zones 5 to 8 for best development.
  
  

Types

• Caterpillars are a problematic pest on liquid ambar trees. These foliage-chewing pests are larvae of moths and butterflies. Leafrollers, for example, are larval moths that grow to a length of 3/4 to 1 inch while displaying green bodies with black heads. Body color changes to a brownish green hue and heads lighten to brown as they mature. Redhumped caterpillars also favor liquid amber trees. These pests, as their name suggests, display red heads and a red humped body segment over a full body color of yellow. Red/brown, black or white stripes also appear down the length of the body. These caterpillars grow to a length of 1 to 1 1/2 inches and mature into moths.
  
  

Damage

• Leafrollers feed on leaves for approximately one month during spring and then roll leaves over themselves as a protective cover, keeping the leaf closed with silk threads. These caterpillars result in defoliation and often lead to severe leaf drop during extreme infestations. Their silk threads also create a mess on tree surfaces and plants below. Redhumped caterpillars feed on leaves, eating all plant tissue but veins, a process referred to as skeletonization. Typically most problematic during summer months, this caterpillar feeding results in minor leaf drop of individual branches to extreme leaf drop of the entire tree. Particularly on weak, stressed plants, foliage-chewing caterpillars can result in dieback and plant death when heavy infestations strip trees of all leaves.
  
  

Solutions

• To control leafrollers, release natural enemies like tachinid flies that kill leafrollers without causing further damage to your plants. Purchase natural enemies from garden supply stores, catalogs or online. For redhumped caterpillar control, release parasitic wasps like Cotesia species or predators that hunt and kill caterpillars like lacewings. Spray the microbial insecticide Bacillus thuringiensis, or Bt, onto your trees for an effective, low-toxicity insecticidal control method for both types of caterpillars.