George Zhuang, UC Cooperative Extension Specialist, and Manuel Marin Jr, PCA and California Raisin Grower, discuss some of the best practices for controlling ants and vine mealybug in your vineyard. Key takeaways include improved vineyard monitoring practices, specific methods of ant and Vine Mealybug control, and new ideas to bring home to your farm.
Special thanks to Bayer Movento Insecticide for making this episode possible.
Vine mealybug (Planococcus ficus) has become one of the most economically damaging pests in California vineyards. Left unmanaged, infestations can reduce yield, weaken vines, lower sugar content and spread viruses like leafroll, which contribute to sudden grapevine collapse.
The good news is effective control is possible with the right timing and integrated approach.
In this guide, we break down proven strategies used by California growers to control vine mealybug based on field insights and expert interviews featured on the California Ag Network channel.
Vine mealybug is a small, sap-feeding insect that:
· Hides under bark, in clusters and on roots
· Produces sticky honeydew that attracts ants and encourages sooty mold
· Reproduces rapidly in warm climates like California’s Central Valley
· Multiple generations per year.
· Protected hiding spots make detection more difficult and contact sprays less effective.
· Can vector or spread various vineyard diseases like grapevine leafroll disease and others.
· White, cottony masses under bark or on clusters
· Sticky residue (honeydew) on leaves and fruit
· Black sooty mold developing on vines
· Increased ant activity (ants protect mealybugs)
Ant presence is often your first indicator of vine mealybug. If you have ants in your vineyard, you probably have vine mealybug.
So, you’ve scouted your vineyard and found vine mealybug: what next?
The most effective approach combines timing, chemistry, biology and monitoring.
· Dormant and early season control
· Growth stage foliar sprays
· Biological control (natural enemies)
· Ant control
· Monitoring and timing
Prevention is the best medicine. An insecticide spray during late dormancy or at bloom is usually enough to control their population all season long for milder infestations. There is a lot that goes into determining which chemistries to use such as soil conditions and specific regional climates. The UC Cooperative extension also recommends considering other pests in your treatment in strictly preventative situations. Broad spectrum pesticides can take care of more problems than just vine mealybug and reduce the number of passes through the vineyard. Be aware, however, that broad spectrum insecticides can also reduce beneficial insect populations so be sure to consult your Pest Control Advisor for the best dormancy and bloom treatments.
Other helpful strategies include:
· Remove loose bark to expose hiding populations
· Apply delayed dormant insecticides if the pressure is high
This stage is critical because you’re targeting populations before they explode
While the vine mealybugs are developing, it’s essential to use systemic insecticides applied through drip irrigation where possible for the deepest control. Contact insecticides and foliar systemic sprays can contribute to control as well. The crawler stage is when they are most vulnerable so be sure to target early season.
Beneficial insects play a critical role in long -term suppression
· Parasitic wasps
· Mealybug destroyer
It’s important to avoid broad spectrum sprays that kill beneficials, so be sure to consult your pest control adviser for the best in-season treatments.
Ant control is critical in managing growing vine mealybug infestations as ants will protect them in exchange for their honeydew. Without controlling ants, your biological control strategy becomes less effective, and infestations can spread more quickly. To control ants, you can:
· Setup bait stations
· Apply sticky trunk barriers
· Apply targeted insecticides
Monitoring populations is essential as it allows you to time sprays effectively and reduce unnecessary applications thus improving ROI on inputs. Understanding the movements and stages of the infestation is essential for effective control. Growers often use a combination of pheromone traps and visual scouting under the bark to detect and track vine-mealybugs.
· Vine mealybug requires year-round management.
· Timing of control methods is everything.
· Combine chemical control, biological control, and ant management strategies.
· Monitoring tools dramatically improve effectiveness.
Vine mealybug is not a one-time fix; it’s a management system. Growers seeing the best results stay proactive, use integrated strategies and adjust based on monitoring data.
Check out this video on control of Vine Mealybug HERE
Check out our webcast on scouting for Vine Mealybug HERE
— By Hyrum Malcolm, Publisher
Kent Daane, UC Cooperative Extension Entomology Specialist, and Jeannine Lowrimore of Pacific Bio Control join American Vineyard Live to discuss some of the best practices for control of Vine Mealybug and other vineyard pests this summer. Watch the one hour presentation now or listen at the links below.
Special thanks to the title sponsor Pacific Bio Control.
Watch our previous Presentation: What Weeds are Telling You About Your Soil Health with American Vineyard Live
The arch nemesis pest of the California grape industry continues to spread to more grape growing areas. Vine mealybug damage not only leads to black sooty mold on grapevine leaves and clusters, but it can also transmit and spread grapevine leafroll associated viruses that have been devastating vineyards. Watch this brief interview with UCCE Kern County Entomology Advisor David Haviland as he encourages an integrated or combination approach to combatting this pest.
Please thank this video’s sponsor Ranch Systems for their industry support.
Vine mealybug has never been more widespread across the grape growing regions of California than it is now. Watch this video interview with Nathan Mercer from the Kent Daane Lab at UC Berkeley, who shares a more effective and collaborative way to control this pest in vineyards. Read more about vineyard pest management in American Vineyard Magazine.
Please thank this video’s sponsor Suterra for their industry support.
Many insect pests currently plaguing California agriculture are not native to the state. As grape growers continue to battle pests like vine mealybug and are threatened by other potential pests such as spotted lanternfly, watch this brief interview with Lodi PCA/CCA Larry Whitted as he reminds growers how important it is for imported grapevines to be properly quarantined and screened before being planted in the vineyard. Read more in American Vineyard Magazine.
Please thank this video’s sponsor Suterra for their industry support.
Santa Rosa, Calif., (August 2, 2017) – In the spring, grapevine nurseries will deliver tens of thousands of vines for new developments and vineyard blocks scheduled to be replanted in Sonoma County. Vines will also arrive to replace plants lost to Pierce’s disease and those that were pulled because of leafroll or red blotch disease. For new and redevelopments, sig- ni cant resources and time were invested months before the delivery date to insure that on the day of planting the site is prepared, the irrigation system functions, stakes or plant markers are in and labor is available. Given these “times” one more item should be added to that long list. Vines should be inspected for vine mealybug by your crew before the vines are planted and if the pest is found, the Agricultural Commissioner o ce should be informed.
Vine mealybug (Planococcus cus) was rst discovered in Coachella Valley in 1994 and in 1998 it was found in
vineyards in Kern and Fresno Counties. Within the next 5 years it was in 16 counties and infested plant mate- rial was one of the contributing factors to that rapid spread. Although the movement of vine mealybug on nursery stock is far less of an issue now than it was prior to 2003, in the long run, it pays to spend time looking at vines while they are in the ats just to be certain the pest is not seen. Once vine mealybug becomes established in a block it must be controlled every year with an IPM program that utilizes insecticides and eventually mating disruption plus diligent monitoring to evaluate e cacy.
Vine mealybug is spread naturally by wind and birds and by farming practices that move the immature insects to other areas inside the block and to adjacent blocks. ere are 3 to 4 overlapping generations in the North Coast and pest populations increase throughout the grow-
ing season. By midsummer, all stages of the insect can be found on canes, clusters, leaves, petioles as well as under the bark on trunks and cordons. As they feed, they excrete copious amounts of honeydew. Vineyard equipment and clothing is easily contaminated when it contacts sticky plant parts that contain young immature insects (crawlers) which are less than 1 mm long.
Grapevine nurseries take measures to prevent dormant and green benchgra s from becoming infested with vine mealybugs. e CDFA Nursery Stock Pest Cleanliness Standards requires nursery stock to be free from vine mealybug. Nurseries can be in compliance of the stan- dards of cleanliness requirements by using the Vine Mealybug Trapping and Survey Protocol provided by CDFA. In the protocol, adult vine mealybug males are monitored with the use of sticky traps which contain a lure loaded with a synthetic form of that insect’s sex pheromone.
In lieu of conducting the trapping and survey protocol, nurseries may voluntarily immerse dormant grape cuttings and rootings in hot water following a protocol provided by CDFA. e county Agricultural Commissioner’s sta must approve of the dipping equipment and ensure the recording thermometers are calibrated. Most nurseries routinely hot water dip and do so under a compliance agreement with their Agricultural Commissioner’s o ce.
Green gra ed vines can’t be immersed in hot water and there is no protocol currently available for treating these vines. Nurseries apply insec- ticides and take other measures to prevent vines from becoming infested during the production process. e wax that is used to protect the gra union also protects insects that get under the wax.
Given that vine mealybugs continue to spread within grape growing regions in California, vineyards are at risk of becoming infested. Infested plants from nurseries are rare, but it happens. Taking the time to inspect them on-site is critical. Budgeting labor hours to inspect vines before planting may reduce farming costs in the future if infested vines are not planted – and your neighbor does the same.
By Rhonda Smith, UC Cooperative Extension Farm Advisor