Leafhopper Blog

Nymphs In 2018, we conducted weekly nymph counts at three vineyard locations in Mendocino County from May 24- September 6. The first emergence of VCLH nymphs occurred during the week of May 14th (Table 1, Figure 1) and densities peaked on June 8, July 6, August 12 and September 4.

Monitoring efforts during the week of May 14th showed the first emergence of VCLH nymphs for the season (see Table 1/Figure 1 for # VCLH nymphs per leaf).

Monitoring efforts during the week of May 14th showed the first emergence of VCLH nymphs for the season (see Table 1/Figure 1 for # VCLH nymphs per leaf).

Monitoring efforts during the week of May 14th showed the first emergence of VCLH nymphs for the season (see Table 1/Figure 1 for # VCLH nymphs per leaf). The numbers of nymphs decreased on the week of June 11th as the three vineyards we are monitoring were sprayed around that time.

On July 9 we surveyed parasitism of Western grape leafhopper (WGLH) and Virginia creeper leafhopper (VCLH) across 9 sites in Mendocino and Lake counties (Fig. 1). WGLH parasitism was fairly consistent (average 38%), but there was little to no VCLH parasitism (average 0.6%).