- Author: Houston Wilson
Last week we made our first observations of Western grape leafhopper (WGLH) eggs on chardonnay in the Ukiah/Talmage and Upper Lake areas (Fig. 1). Egg deposition by Virginia Creeper leafhopper (VCLH) continues on white varieties in both counties. Leaf development of red varieties at the sites we're monitoring is still inadequate to support leafhopper egg deposition.
This past week we encountered a few VCLH eggs that showed signs of nymph emergence in a chardonnay vineyard near Hopland. This represented approximately 7% of the total VCLH eggs in that vineyard, but emergence will likely increase this week. We will begin to monitor for nymphs this week.
We have dropped the McDowell Valley site in Mendocino County since it was redundant with the Hopland site. A third site from Big Valley was added this week in order to track leafhopper development on a white variety in this region.
Another batch of Anagrus daanei, the parasitoid that attacks VCLH, was released in a vineyard near Talmage on April 28.