The “100 Days War”


Right now there’s a war going on in California. It’s not your typical war, but it happens every year from the end of January into June.

Plants being inspected for GWSS egg masses before being shipped

Plants at a Southern California nursery being inspected for GWSS egg masses before being shipped

“The ‘100 Days War’ is how the nursery industry refers to this period, because that’s when many of them ship roughly 70% of their nursery stock production for the entire year,” said David House, President of Village Nurseries. “Some of the nurseries that ship to the big retailers are operating 24 hours a day, six days a week during this time,” added House.

During this period major holidays, including Valentine’s Day, Easter, Mother’s Day and Father’s Day, take place, all of which involve giving flowers. Then, to top it all off, it’s also when people look around their yards and decide to do some spring landscaping and plant vegetable gardens. As a result, some nurseries are shipping as many as 20,000 plants a day during this time.

Plants being sprayed prior to shipment to a non-infested area.

Right in the middle of this “war” is when the first glassy-winged sharpshooters (GWSS) of the season begin to emerge as well. With over half of California’s nurseries located in Southern California’s GWSS infested areas, the challenge is to keep plant shipments free of GWSS. During the first two months of 2018 there were 5,207 shipments from GWSS-infested areas to non-infested areas of the state. That’s up by 456 loads, or over nine percent, compared to the first two months of 2017.

With the GWSS populations increasing during this period, there’s an added chance of egg masses being present on nursery stock. Plants that have been identified as hosts for GWSS receive extra attention and efforts by nurseries, which trap, treat, inspect, and safeguard plants to make sure they are free of GWSS.

Plants shipped to non-infested areas must be certified as GWSS-free before being shipped and may be inspected once again when they arrive at their GWSS-free destinations before they are released for sale at local outlets. “The county teams that provide inspection and certification services have been very cooperative despite their workloads,” said Robert L. Crudup, Jr., President and CEO of BrightView Tree Company. “It requires a working partnership to smooth out any bottlenecks and to keep the lines of communication open.”

Two leaves showing a fresh and an old GWSS egg mass found during an inspection.

Two leaves showing a fresh and an old GWSS egg mass found during an inspection.

All this effort by nurseries and county agricultural staff really pays off. In 2017, GWSS were found in only six of 36,700 shipments, a success rate of 99.98 percent.

And what happens in the rare event that GWSS adults, nymphs, or egg masses are found in a shipment at their destination? The shipment may either be destroyed, returned to origin, or rendered pest-free and released.

With the increase over last year’s numbers, this year’s “100 Days War” looks to be a busy one. All the troops, from nursery workers to county agricultural commissioners’ staffs, stand ready to once again help stop the spread of GWSS.

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