Scott W. Ludwig, Extension Program Specialist – IPM
The Departments of Agriculture in the states of Arizona, California, and Oregon are now requiring that plants shipped into their state are free of all glassy-winged sharpshooter, Homalodisca coagulata, life stages.
While most nursery producers are not familiar with this pest, it has been found east of a line from Ft. Davis to Big Spring to Childress. The glassy-winged sharpshooter feeds on a wide variety of plants with a host range of over 200 species. Known hosts in Texas include pine, sweet gum, citrus, stone fruit, crepe myrtle, ash, birch, and holly.
Glassy-winged sharpshooters are not nursery pests; however they transmit Pierce’s disease in grapes. As a result, Arizona, California, and Oregon have instituted quarantines for this insect, and it is important to make sure Texas nurseries are not exporting this pest.
Eggs are sausage-shaped and are laid side-by-side under the leaf epidermis in masses ranging from 1 to 27. Egg masses appear to be greenish water blisters on the undersides of the leaf.
Nymphs are greenish grey and similar in shape to the adults. The nymphs do not have wings and are generally smaller than the adults, ranging in size from 1/10 inch to nearly 1/2 inch long.
Adults are approximately 1/2 inch in length and are dark brown to black with a lighter underside. The upper parts of the head and back are stippled with ivory or yellowish spots with the wings being partly transparent with reddish veins. Watery excrement often collects on either side of the insect, appearing as large white spots.
Over-wintering adults lay their eggs in early spring. Nymphs hatch in about two weeks and proceed to feed into leaf petioles or small stems, while they progress through four molts before becoming winged adults. A second peak in adult activity occurs in late summer. The peak population occurs in Texas around Memorial Day.
SCOUTING BEFORE SHIPPING
Inspect the entire tree to ensure that there are no adults or nymphs present on the plants at the time of shipping. If leaves are present, inspect the underside of the leaves for eggs.
If you are shipping into Arizona, California, and Oregon you should have your plants inspected by the Texas Department of Agriculture to have glassy-winged sharpshooter included on your certificate.
Many formulations of systemic insecticides containing imidacloprid or acetamiprid can be used to provide residual control of adults and nymphs; however, it is still important to inspect treated trees and other plants before shipping to ensure there are no hitchhikers.
Products containing carbaryl, methiocarb, bifenthrin, cyfluthrin, permethrin and pyrethrins may be registered for sharpshooter control. These products could be apply to plants that have a sharpshooter infestation prior to shipping.
The insect grower regulator buprofezin can be used to control the immature stages of the sharpshooter.