Vineyard Mealybugs in the North Coast Region
The three most important mealybugs (below) in the North Coast are vine mealybug (VMB), grape mealybug (GMB), and obscure mealybug (OMB). Gill's and long-tailed mealybug are present in other regions, but not prevalent in the north coast. Mealybugs can be found anywhere on the vine (trunks, cordons, leaves, etc.). They are phloem-feeders, and excrete honeydew. Excessive honeydew can lead to the growth of sooty mold that can soil leaves and clusters. All vineyard mealybugs transmit grapevine leafroll-associated viruses (GLRaV). Male mealybugs do NOT transmit GLRaV because they do not feed in the adult stage; as nymphs they are vectors.
More information: UCIPM: Vine mealybug, UCIPM: Mealybug identification, UCCE Napa County, UCCE Sonoma County
Information adapted from materials made by UCIPM, UCCE Napa, UCCE Sonoma, and Bettiga et al. 2013. Grape Pest Management. Third edition. University of California, Agriculture and Natural Resources, Richmond, CA, USA.
Video: M. Hobbs July2020
VMB population on grapevine trunk.
(A) Vine mealybug (Planococcus ficus)
(B) Grape mealybug (Pseudococcus maritimus)
Short caudal filaments
PC: Malcolm Hobbs
PC: Jack K. Clark
(C) Obscure mealybug (Pseudococcus viburni)
PC: Kent Daane
PC: Jack K. Clark
Figures A, B, C, D: the four common mealybugs and their defining characteristics relevant to the North Coast/ Central Coast region.
Click on the image to visit the UC IPM website for more details on management and identification.
(D) Long Tailed mealybug (Pseudococcus longispinus)
Identifying male mealybug in traps
Click on the photos for a downloadable copy of the identification sheets
Common features of male mealybugs
Zoom Progression of Male Mealybugs in Traps
Vine Mealybug: detection & monitoring
Trap data collected through the Napa Pest and Disease Control District were used to indicate potential risk for spread of vine mealybug in Napa County
Click on map below to enlarge or read it in Spanish!
Male Vine Mealybug detections from 2012-2021 in Napa County
Map by: Sarah L. MacDonald