Leafhopper Newsletter

Nymph emergence continues - June 1

We have been seeing mostly 2nd, 3rd and 4th instar (stage) nymphs and expect more 4th and 5th instars to appear this week. Some additional leafhopper nymphs will continue to emerge in the coming week as well. Approximately 79% of the Virginia creeper and 48% of the Western grape leafhopper eggs have emerged.

This is the week to monitor your vineyard to determine is control measures will be necessary.

Parasitism of Western grape leafhopper has been consistent at all sites since May 5, indicating that the regional population of Anagrus spp. parasitoids have colonized the vineyards. There is practically no parasitism of Virginia creeper leafhopper.

A batch of Anagrus daanei, the parasitoid that controls Virginia creeper leafhopper, was released on May 26 in Mendocino County near Hopland.