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Sharpshooters

Blue-Green Sharpshooter Glassy Winged Sharpshooter

The bug on the left is the Blue-Green Sharpshooter(BGSS), the traditional vector of Pierce's disease (PD). PD is the killer of grape vines in warm climate sites which would be great for viticulture were it not for this pest. There is currently no known cure for PD.

The BGSS plays host to a bacterium which, when introduced to green plant tissue, results in the clogging of the plant's plumbing system and denial to the plant of the necessary water to keep it alive.

The BGSS is not the most efficient accessory to a crime. It does not like arid regions, and tends to stay close to bodies of water. This characteristic has retarded its ability to spread PD, and resulted in the "hot spot" concept of grape growing in the southern U.S. You don't try to grow grapes varieties in a hot spot that are not PD resistant. But nearby areas are always worth a try.

The bug on the right is the Glassy Winged Sharpshooter (GWSS). It also is a vector of PD and a relative newcomer to the southern U.S. It demonstrates no particular affinity to bodies of water. This characteristic combined with other talents, permits the GWSS to expand its territory much more rapidly. It is currently threatening billions of dollars worth of prime viticultural territory (e.g. two thirds of the State of California).

The GWSS may be a blessing and a curse. With so much at stake, there is likely to be an enormous amount of research funding thrown at the PD problem. In addition to being a host for the lethal bacterium, the GWSS could be the unwitting catalyst for research which will result in a cure for Pierce's disease.



April 14, 2000
War has been declared aganist PD!
USDA's Declaration is here in the GGN.
Read this one pager.
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