Taking Aim at a Sharpshooter

San Diego, CA - The landscaping of our California highways are so well maintained by the California Department of Transportation (Caltrans) that motorists take it for granted.

Now that the springtime blooming season is winding down, we can be thankful for the mild San Diego climate. Our weather allows the beautiful oleander bushes along our freeways to bloom for most of the year. In colder climates oleanders only bloom from the early summer to fall.

The plant was the perfect choice for California’s freeways. It needs little water, has a long blooming season, handles constant pruning with grace, it is simple to propagate, establishes itself easily and is resistant to air pollution.

Sounds like perfection, doesn’t it? As in many things that are too good to be true, there is trouble in paradise. Caltrans had to stop planting oleanders because of the invasion of non-native insect, the glassy-wing sharpshooter. This pest is responsible for a major outbreak of Pierce’s Disease (PD) in Southern California.

There is no cure when the disease afflicts a plant. Within 3 to 5 years of the first noticeable symptoms the plant dies. So we are losing our oleander plants. Caltrans stopped planting them in the late 90s. Freeway expansion has eliminated many more plants that have not been killed by disease. Caltrans is looking for an alternative, but they will never find a better replacement.

Even worse is the effect on Southern California’s budding wine industry. Sharpshooters love grape vines. Thankfully they only feed on the edge of the vines and the infected portion of the plant can be cut away with pruning. Unfortunately, infections are often undetected until the disease has spread. This cost 20 million dollars of damage in the last major outbreak of PD over 10 years ago in Temecula wine country.

The California Department of Food and Agriculture is taking aim against the glassy-winged sharpshooter, but the pest is a prolific breeder and is highly mobile. Various predators have been evaluated, but so far we haven’t had much luck. Meanwhile, containment strategies have been implemented with only minor success.

While aggressive applications of pesticides blunted the worst outbreak over 10 years ago, it is imperative that we find a long-term solution to the problem. Unfortunately, State Agriculture Secretary, Karen Ross, proposed a list of budget cuts that include the elimination of 1.12 million dollars from the $3.12 million allotted to the Pierce’s Disease management program.

So let enjoy the year round displays of the oleander plants while we can. While we are at it, we should hope and pray that the glassy-winged sharpshooters don’t make it to Northern Californian wine country!