New pheromone tool helps you fight vine mealybugs in grapes
By Stephen Vasquez, Walt Bentley and Kent Daane
A new tool is now available for managing vine mealybug (Planococcus ficus) in vineyard production systems. Lavandulyl senecioate is a chemically formulated sex pheromone developed by University of California researchers and manufactured and distributed by Suterra. Suterra’s patented membrane dispenser (Fig. 1) releases a consistent stream of pheromone that confuses the males, thus disrupting the mating process.
Figure 1. Vine mealybug pheromone dispenser.
This reduces the ability of males to locate and mate with females, resulting in an overall decrease in vine mealybug (VMB). Mating disruption works best when integrated into a well planned VMB management program. A balanced integrated pest management program for VMB should include the following:
- Field crews trained to identify VMB and damage
- Season long monitoring using VMB pheromone traps
- Sanitation protocols that include pressure washing or steam cleaning equipment
- Mating disruption
- Biological control
- Targeted and/or selective use of insecticide treatments
- Ant control
Know thy enemy
The first aspect of managing VMB is being able to identify the pest. It is imperative that field crews be well trained to look for and identify the pest and its characteristic damage. If VMB is identified early, success of managing its spread during the season and over seasons increases.
Figure 3. Vine mealybug adult male (left) and female with ovisac starting to be deposited.
A sign that the pest has infested a vineyard is the presence of sticky honeydew on clusters, leaves and bark. As the season progresses, the excessive amount of honeydew produced by VMB encourages sooty mold growth. Mealybug body parts and, especially, egg cases and crawlers will be found throughout fruit clusters and over the canopy.
A heavy infestation should not be mistakenly attributed to grape mealybug
(Pseudococcus maritimus). Grape mealybug will not produce such levels of honeydew. Less severe VMB infestations may not be as noticeable, with the canopy exterior void of mealybug, honeydew and sooty mold, but insects will be found in the crown of the plant.
Vines where VMB signs and symptoms are found should be flagged, mapped, treated and monitored throughout the season. The best time to use mating disruption is when VMB populations are low. Pheromone traps should be placed throughout the vineyard to monitor VMB populations. VMB traps use the same pheromone used in the mating disruption dispensers and are capable of attracting male VMB at least 100 yards from the trap.
Place one trap for every 20 acres. When traps record less than 5 male VMB, they are probably being pulled from outside the vineyard. Recordings of male VMB in the range of 10-15 should be followed up with a survey of the vineyard for female VMB.
It is this type of situation—low male catches and female finds—that warrant the use of mating disruption. To maximize the affect of mating disruption, approximately 200-250 pheromone dispensers (Fig. 2) per acre should be placed throughout a vineyard.
Figure 2. Spent vine mealybug pheromone dispenser shown in vine at the end of the season. Dispensers are typically placed in the vineyard in April/May.
For the best results, pheromone dispensers should beplaced in the vineyard before or shortly after VMB begins to move from its overwintering locations. Managing high VMB populations using mating disruption is cost prohibitive and should involve first using insecticides registered for VMB management.
There are several good sources for additional information that discuss VMB and its damage.
- A publication that should be shared with field crews is titled Vine Mealybug: What YouShould Know, UC ANR Publications 8152. It is available at your local UC Cooperative Extension Office for free or online at: http://anrcatalog.ucdavis.edu/pdf/8152.pdf
- Mealybugs in California Vineyards, UC ANR Publication 21612 discusses the most common mealybugs found in vineyard settings. It is a great resource for identifying mealybugs and includes a key that uses unique characteristics for mealybug identification.
UC has several web sites withVMB information that are updatedregularly. New biology and management information using registered insecticides can be found at these sites.
- Mealybug in California Vineyards located at: http://www.vinemealybug.uckac.edu/
- UC IPM Guidelines for Grapes located at:http://www.ipm.ucdavis.edu/
- Vine Mealy bug located at: http://ucipm/PMG/r302301911.html
- Grape, Obscure, Longtailed located at: http://ucipm/PMG/r302301811.html
Stephen Vasquez is the UC Cooperative Extension viticulture advisor in Fresno County. Walt Bentley is the UC IPM advisor based at UC Kearney Agricultural Center, Parlier, CA. Kent Daane is a UC Cooperative Extension Specialist based at UC Berkeley and Kearney Agricultural Center. Photos courtesy of K. Daane.
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