Privets, or ligustrum, are shrubs and trees that are usually planted as hedges. They grow well in either full or partial sunlight and tolerate most soils. Ligustrums are vulnerable to attack from a number of different insects.
Ligustrum weevils, or Ochyronmera ligustri, are approximately .15-inch long, shiny brown insects with long rounded bills. Blackvine weevils (Otiorhynchus sulcatus) are between .25 and 0.4 inches long. All blackvine weevils are flightless females with black bodies. Privet rust mites, which are too small to see without magnification, have brown, spindle-shaped bodies. Female euonymus scales are immobile grey or brown insects that spend their lives attached to plants.
Ligustrum weevils chew holes in privet foliage and destroy buds, while blackvine weevils feed on foliage during the night. Privet rust mite infestations cause browning and curling in plant leaves. Euonymous scale insects feed on foliage, causing dieback, reduced photosynthesis and stunted growth.
Ligustrum weevils are controlled by removing privet flowers and fruits. Soil treatments of imidacloprid insecticides kill blackvine weevil larvae. No known control methods are available to reduce privet rust mite populations; healthy plants that receive appropriate irrigation and fertilisation can tolerate insect infestations. Euonymous scale insects are controlled by planting insect-resistant cultivars, by keeping plants healthy, and by using horticultural oils or insecticides.
- University of California Statewide Integrated Pest Management Program: Privet--Ligustrum Spp.
- North Carolina State University: Ligustrum Weevil
- Colorado State University Extension: The Black Vine Weevil Otiorhynchus Sulcatus (Fabricus)
- North Carolina State University: Privet Rust Mite
- Canadian County Oklahoma Cooperative Extension Service: Euonymus Scale
- University of California Statewide Integrated Pest Management Program: Gall and Blister Mites (Eriophyid mites)