Leafhopper Newsletter

Adults and eggs peaking, nymphs increasing - Aug. 31

MENDOCINO COUNTY

Densities of both VCLH and WGLH adults and eggs remain elevated at most sites while nymph populations of both species continue to increase. For the WGLH, this nymph population increase represents the second brood whereas for VCLH the nymphs are likely a mix of second and third brood (later instars are from the second brood and earlier instars are from the third brood)

LAKE COUNTY

VCLH densities are generally low and more variable across all sites (less than 3 adults per trap). While no VCLH nymphs have been observed since mid-July, if they do appear they will represent the third brood.

WGLH adult populations have peaked (or are currently peaking) at all sites and we have been seeing increased nymph densities at most sites with the exception of "Scotts Valley" (sharp decline this week) and "Finley" (no WGLH nymphs observed since June). These nymphs represent the second WGLH brood.

PARASITOID RELEASE PROGRAM

Two batches of Anagrus daanei, the parasitoid that controls VCLH, were released on August 26 at a vineyard in Mendocino County in the Talmage area. The next release is scheduled for September 2 in Mendocino County.