Origin:
Native to the southeastern U.S., but introduced to California and other southwest states in the 1990’s where it potentially may be destructive to vineyards and other crops and ornamental plantings.
Biology:
As a leafhopper the GWSS feeds by piercing plant tissues with its proboscis, and removing plant fluids. In the process of feeding it may inoculate the plants with a bacterium called Xylella fastidiosa, which causes devastating diseases in a variety of plants, such as Pierce’s Disease of grapes or Leaf Scorch of almonds, oleander, or mulberry. It is capable of feeding on hundreds of different crop and ornamental plants, including citrus, oaks, and maples. At the time of writing there is no cure for the disease once introduced into the plant. In temperate climates there may be two generations per year, with adults active even in January and February, when they may feed on the thin stems of deciduous trees as well as on citrus or non-deciduous ornamental plants.
Identification:
The adult insect is large compared to other leafhoppers, with a length of nearly one half inch. It is very dark brown and with a slightly speckled look. Like other leafhoppers the dorsal end seems to protrude forward from the head and the wings cover the abdomen and are held roof-like over it at rest. A very characteristic feature may be seen on females shortly prior to egg laying, as they secrete a chalky white material that they transfer to the sides of the wings, creating conspicuous white spots. The top of the head also is covered with a pattern of small white spots or speckles.
Characteristicts Important to Control:
Given the serious problems from its role as a vector of plant diseases an effort is being made to establish a good management program. Currently no effective cultural or biological controls are known, and since the principal problem is the disease, which only a few of the insects could spread, management is difficult. In California it may still be a quarantine species, and if found should be reported to the County Department of Agriculture.
