- Author: Houston Wilson
Published on: May 9, 2017
This week eggs of both Virginia creeper leafhopper (VCLH) and Western grape leafhopper (WGLH) were found on red varieties in the Red Hills and Big Valley areas of Lake County (Fig. 1A). While we're not monitoring red varieties in Mendocino County, leafhopper egg deposition is likely starting to occur on red varieties there as well.
VCLH and WGLH egg deposition continues to increase on white varieties in both counties (Fig. 1).
No nymphs of either VCLH or WGLH have been observed yet.
In order to provide better data on regional leafhopper life-stage development, we've changed a few of the sites that we monitor in Lake County:
- "Upper Lake 1" was dropped due to an early season pesticide application, which killed off all of the VCLH. This is now replaced by "Upper Lake 2".
- "Big Valley 1" was dropped because it had very low leafhopper densities and was redundant with "Big Valley 2" (both are red varieties). In place of "Big Valley 1" we've added "Big Valley 4", which is a white variety with higher leafhopper densities.
- We've also replaced the "Red Hills" site with "Red Hills 2", since "Red Hills" had very low leafhopper densities.
Last Friday May 5 we released another batch of Anagrus daanei in a vineyard near Talmage.
Thanks for the update (and good eye). The Anagrus parasitoids that attack leafhoppers are active in most vineyards by now, though populations vary from site to site. We haven't seen any signs of WGLH parasitism at the sites we're currently monitoring, but I expect that to change in the near future. As for VCLH, still no signs of parasitism, but hopefully we can change that with these releases of Anagrus daanei.