Insecticide for Azalea Lace Bugs

Azalea Lace Bug Basics

• According to the University of Tennessee, the azalea lace bug was first introduced to America from Japan in the early 1900s. Since then, it has caused no end of problems for gardeners across the country. Azalea lace bugs can cause damage to evergreen and deciduous varieties of azalea. At only 1/8 inch to 1/16 inch in length, an adult lace bug can cause significant damage by sapping nutrients from the azalea leaf.

Identifying Damage

• Azalea lace bugs do their damage on the leaves of the plant. The most common symptoms of azalea lace bug damage are spotting or discoloration, even bleaching, on the top surface of the leaf. In severe cases, the azalea lace bug can even cause an entire leaf to go white and drop off the plant. In addition to damage on the top of the leaf, the bottom of the leaves will have a black, shiny, dry excrement left behind by the bugs.

Insecticides

• A vast number of insecticides can be used to combat the azalea lace bug. A few notable ones are acephate, thiamethoxam, dimethoate and malathion. An exhaustive list, including a list of nursery-only insecticides, can be found in the Resource section below. For residential spraying, simply look for an insecticide that contains one of these chemicals and apply as directed.

Application and Timing

• To get the most out of spraying an insecticide, the applier should always keep in mind when and how to best apply. Azalea lace bug infestations occur most frequently in July or August although weather and other environmental factors can affect this.

  Furthermore, insecticides work best against this pest when the populations are higher in number. Additionally, the insecticide should be sprayed on the top and the underside of the leaves for best results. Most, if not all, insecticides will contain a guide on their packaging that will help the applier use the product safely and efficiently.

Other Considerations

• Horticultural oil is an oil/water mixture that, when sprayed onto an infected azalea, can be very effective in eliminating lace bugs. Furthermore, horticultural oil is more attractive to some gardeners because it is a more environmentally friendly solution to the problem.

  Additionally, some gardeners simply choose to spray their azaleas with a strong stream of water in an effort to disrupt the populations of lace bugs. Although not the most effective method of treatment, this method can be used to as a temporary measure.