7/2/2013 - By Matthew Shultz

If I had to pick one insect that is an ornamental pest to be my favorite, it would have to be the lace bug. At first glance these insects look like something out of a Sci-Fi movie. The top of its head and wings are covered in lace-like ridges, often times with colorful patterns, which is where the insect gets its name.

Most species important to the nursery are rectangular in shape and about a ¼” in length. Lace bugs are in the Heteroptera or True Bug order; both the adult and larval lifestages use a piercing stylet to extract liquid from the underside of the leaves. This feeding gives way to a stippled look to the topside of the leaves and is usually a good giveaway to the presence of this pest.

In heavy populations, lace bugs can induce premature leaf drop. Another way to scout for lace bug is to look for dark tar spots on the undersides of the leaves, these are actually their fecal spots. The Eastern US has around 20 different species that are important to the nursery; some more notables include Hawthorn Lace bug, Oak Lace bug, Sycamore Lace bug, Lantana Lace Bug and Azalea Lace bug.

Avocado and Sugarcane lace bugs can be problematic in the south. Most of these pests are host specific while a few will move to an alternate host plant to overwinter on. Lacebugs that feed on woody ornamentals will overwinter as adults in bark splits and branch crotches. These adults become active in the spring with the new flush of growth and will have up to 3 generations per year in the Mid Atlantic, and up to 5 in the South.  The nymphs do not resemble the adults and are covered in spines and very dark in color, they too look like something out of the movie Aliens. These insects will go through 5 instars before reaching the adult lifestage. The larval lifestage is the easiest to control when using conventional insecticides.

Lace bugs can move rather quickly and can also fly from host plant to host plant. Lace bug are easily controlled using a preventative spray program which utilizes systemic insecticides. Tristar, Safari, Flagship and Imidacloprid all work well against lacebugs, as do unsulphonated horticultural oils like SuffOil-X, but coverage is critical with oils.

By Matt Shultz, Horticultural Tech Support Specialist and Sales Representative, Harrell’s LLC.