Glassy-winged Sharpshooter Euonymus spp

Disease Information

Glassy-winged Sharpshooter

Symptoms and damage

The glassy-winged sharpshooter is a large leafhopper that obtains its nutrients by feeding on plant fluids in the water-conducting tissues of a plant (the xylem). Feeding on plants rarely causes significant plant damage, although the insects do excrete copious amounts of liquid that can make leaves and fruit appear whitewashed when dry. The excrement is a special nuisance when shade trees are heavily infested because cars parked under the trees tend to become spotted. During hot weather, heavy populations of glassy-winged sharpshooters feeding on small plants may cause them to wilt.

The real problem associated with glassy-winged sharpshooter, however, is that it can spread the disease-causing bacterium Xylella fastidiosa from one plant to another. This bacterium is the causal agent of devastating plant diseases such as Pierce`s disease of grape, oleander leaf scorch, almond leaf scorch and mulberry leaf scorch.

MANAGEMENT

 Large, yellow sticky traps are commonly used in orchards to monitor for the adults. Sweep nets are also used to monitor for glassy-winged sharpshooter in agricultural situations. Glassy-winged sharpshooter infestations can also be determined by examining the underside of plant leaves for egg masses.

Cultural Control

There are no known cultural controls for glassy-winged sharpshooter. But preventing transport of infested plant material to areas where glassy-winged sharpshooter has not been found can slow its spread in California. Nurseries shipping plants out of an infested area must follow rigorous plant inspection and treatment before the plants are shipped and then the plants must be inspected again after they arrive at their destination.

Chemical Control

The main material used to protect Xylella-susceptible plants in both commercial agriculture and urban landscapes is imidacloprid, which is registered for home and professional landscape use on nonfood crops. Imidacloprid is sold in two formulations: one for soil application and one for foliar application. The soil-application formulation provides the most effective, long-lasting control and is less disruptive to the biological control provided by the parasitic wasps (although it is quite toxic to some predatory lady beetles, such as the vedalia beetle), but it takes several weeks to become effective. Foliar applications of this material are effective for a much shorter period of time and may disrupt biological control agents, and thus are much less desirable.

In instances where the white excrement produced by this pest causes intolerable residues on cars or other surfaces, other insecticides can be applied to infested foliage to provide immediate relief. The least toxic and disruptive to biological control are insecticidal soaps and oils. Insecticidal soaps and oils are only effective in killing the soft-bodied nymphs of the glassy-winged sharpshooter and must directly contact the insect to kill it, so thorough coverage of the plant or tree foliage is essential. Applications of these materials need to be repeated at about 7- to 10-day intervals. Other insecticides are available for foliar applications. However, these materials are much more damaging to the parasitic wasps that are being introduced for long-term control.

 

 



Share this article