Lace bugs on pyracantha
LACE BUGS - Lace bugs are in the genus Stephanitis. Both adults and nymphs feed on the undersides of leaves sucking plant juices and causing splotched or stippled appearance on the upper sides of the leaves. The adults, nymphs and eggs are visible to the naked eye as is a varnish like residue they deposit on leaf under-sides. These insects weaken plants by limiting photosynthesis and energy-storing capabilities. In evergreen plants, the foliar damage can be especially injurious because the leaves that would have remained on the plant for several seasons become useless.
At the Morris Arboretum we see large infestations of lace bugs on a whole range of plants. Different kinds of lace bugs feed on certain plants. For example, many oaks were covered with oak lace bugs, while pyracantha had andromeda lace bugs. Lace bugs came from Japan to Connecticut and are now found from North Carolina to Maine.The insect infestations are worse on plants that are in full sun.The lace bugs overwinter as eggs in the mid-veins of leaves or on leaf under-sides. It is best to control lace bug infestations early in the season to prevent big population build-ups later. At first sign of the insects, spray insecticidal soap and again in middle to late summer if the insects persist. When spraying, pay attention to the under sides of the leaves where the insects are most concentrated.