Vine Mealybug Maps

Interactive Map

Has vine mealybug (VMB) been found near you? Access data from our interactive map to find out. Each square represents a 25-acre area and are colored relative to the range of VMB males trapped. The map is searchable by APN, address or operator identification/permit number. Contact our office if you have questions about the map.

VMB Map GIF Opens in new window

Vine Mealybug Trapping Program Changes for 2019

Our vine mealybug program activities are made possible by Napa County Winegrape Pest and Disease Control District, and the vineyard owners who pay into the annual assessment fund. The Pest District, with the support of the Ag Commissioner’s Office, is very mindful that assessment funds are spent with the highest impact for the greater winegrape industry in mind. Recently the Pest District looked at data analyzed by University of California researchers to review our VMB trapping program. The data presented was made possible by a CDFA Pierce’s Disease Control Program-funded project to study the invasion biology of vine mealybug, with the goal of improving detectability and response. Details can be found in the 2018 Symposium Proceedings online. UC researchers attempted to measure how favorable the different environments throughout Napa County are for VMB to invade and establish populations, by examining environmental, geographic, and human-mediated (roadways, wineries) factors to model habitat suitability in the County. UC researchers also used Napa County trapping data from 2012 – 2017 to analyze the spread of VMB locally.

Vine mealybug trap on a grapevine

Based on this data, the Pest District elected to scale back VMB trapping in the chronically-infested regions of the county (those areas that have had positive male VMB detections in at least 4 of the years of the trapping program.) Ag Commissioner’s staff have still placed traps in the areas identified as low, medium, and high risk, to monitor new infestations. To offset the reduced trapping, we have expanded our biocontrol release program in those chronically-infested areas. Growers are encouraged to monitor and survey their vineyards for VMB, and implement a complete IPM program for mealybug control.