Vine Mealybug - Never Stop Protecting

Year-Long Control is Necessary to Prevent Vine Mealybug Damage in Vineyards

As the 2024 grape harvest comes to a close, viticulturists and PCAs are already hard at work preparing for the challenges of the upcoming season. While there are several management practices necessary to maintain a healthy vineyard, pest management remains a crucial priority. With warmer fall and winter temperatures extending pest activity in the field, it is vital to invest in year-long Integrated Pest Management solutions for damaging pests like vine mealybug.

Warmer Temperatures Extend Vine Mealybug Activity in Vineyards

California experienced another warm September and early October this year. Because the biological processes of insects are linked to climate, sustained warmer temperatures means extended pest activity. In the context of vine mealybug, this manifests as longer reproduction cycles, increased number of generations per year, extensive damage potential as well as virus transmission to vineyards.

Vine mealybug is present in all grape-growing regions of the state, unlike other mealybug species that tend to be more geographically confined. In California, there is potential for seven or more generations of vine mealybug per year. Unlike some insects that diapause, vine mealybug has no physiological break in its development. While it’s true that vine mealybug may migrate under bark or to the root system of vines in the winter, its lack of diapause means pest development and reproduction in these areas is still possible.

Trends in Vine Mealybug Behavior and Damage Potential

All of the previously listed factors combined make managing vine mealybugs an extreme challenge for grape growers. Without a steep drop in winter temperatures, 7+ pest generations per year may become the new normal. Growers can expect significant surges in vine mealybug populations if not managed properly.

Over the past several seasons, Suterra scientists monitored vine mealybug populations in the Napa-Sonoma and Kern County areas. They confirmed that males were still actively searching for females well into mid-November. In our continued conversations with growers, many have shared that vine mealybug crawlers have been detected under plant bark as early as January in some parts of the state – further exemplifying the pervasive, year-round nature of this pest.

Vine mealybug populations of any size have the potential to decrease plant vigor, encourage sooty mold growth in grape clusters, and will increase the transmission of plant viruses like Grapevine Leafroll-Associated Viruses (GLRaVs). Perhaps the most devastating consequence of vine mealybug infestations, the virus only takes one hour to transmit from insect to plant. Once present, GLRaVs disrupt the flow of nutrients through the phloem, causing a myriad of physical symptoms in vines and contribute to sudden vine collapse.

Year-Round Vineyard Protection with Suterra Mating Disruption for Vine Mealybug

The vine mealybug’s capacity to spread incurable leafroll viruses as well as directly damage clusters means a persistent significant threat of economic loss to vineyard producers. Coupled with an accelerated biological cycle due to warm weather conditions, year-round treatment strategies for this pest are essential. The importance of a year-round IPM program has also been stressed by the University of California’s Statewide Integrated Pest Management program as a way to manage key pests at each stage of crop development and evaluate their effectiveness at the end of the season.

Suterra’s portfolio of products for vine mealybug includes Celada^TM VMB, a novel dispenser with more than a decade of mating disruption experience and grower feedback behind it. Its proprietary resin blend, expertly engineered release profile, and high-quality pheromone active ingredient allow Celada to thrive in all field environments for 365 days. With zero re-entry interval, zero pre-harvest interval, and MRL exemption, grape growers can also rest assured that they use a worker-friendly and crop-safe solution.

For more information on vine mealybug monitoring or treatment, please contact us.