Updates on grape and vine mealybug development in Napa County vineyards
Virtual Vertebrate Pest Council Webinars!
Feb 26, 2021
Join us for the first virtual Vertebrate Pest Council Webinars!
Tuesday, March 30, 2021-Register here.
- Ground Squirrel Management- Carolyn Whitesell, UC Division of Agriculture & Natural Resources
- Gopher & Vole Management- Roger Baldwin, UC Davis
- Using PRESCRIBE- Ed Duarte, Alameda County Dept. of Ag/ Weights & Measures
Wednesday, March 31, 2021-Register here.
- Navigating AB1788-Jim Hartman, Los Angeles County Dept. of Ag./Weights & Measures
- Rodenticide Exposure in Wildlife- Jaime Rudd, California Dept. of Fish & Wildlife
- Active Ingredients & Modes of Actions for Managing Rodents in CA- Niamh Quinn, UC Division of Agriculture & Natural Resources
Thursday April 1, 2021-Register here.
- Rat Trapping 101- Niamh Quinn, UC Division of Agriculture & Natural Resources
- Health Significance of Rodents for Rodent Managers- Laura Krueger, Orange County Mosquito & Vector Control District
- Controlling Rodent in Homeless Encampments- Michael Mooney, Alameda County Vector Control Services District
See attached event flyer for additional details.
Download (617KB PDF)
Mechanical Canopy Management Demo, Friday, May 10, 2019
May 7, 2019
FREE Mechanical Canopy Management & Trunk Suckering Demonstration
You do not need to RSVP.
Friday, May 10, 2019, 9 am – 11 am
UC Davis Oakville Experimental Station - Map
1380 Oakville Grade Road, Napa
We will demonstrate how to capture vineyard variability via canopy reflectance, turn it into useful knowledge, and then manage canopies at a variable rate. The demonstration will start at 9:00 am and will wrap up at 11:00 am. There is no cost to attend.
Download (250KB PDF)
Vine mealybug management and FAQs
Mar 16, 2015
The Napa County Wine grape Pest & Disease Control District sponsored a seminar on vine mealybug (VMB) on February 25. We discussed VMB detection, biology and management. As a follow-up, this article summarizes significant points from the day, focusing on issues that are of particular concern for management of VMB, and also addresses FAQs.
Download (10,329KB PDF)
Vine mealybug update
May 1, 2014
Vine mealybug was monitored at a Carneros vineyard on April 29, 2014.
This edition of the UCCE-Napa County VMB newsletter contains:
Update on VMB populations
Male VMB flight
Photo documentation of biological control with Anagyrus pseudococci
Photo guide to identification of various VMB life stages
Download (5,111KB PDF)
Grape Mealybug Update
Mar 26, 2014
On Monday, March 24, I monitored grape mealybug populations at a vineyard in Oakville.
I found 1st and 2nd instar nymphs on one year old wood. No GMB nymphs were found on the permanent wood or on leaves. Sampling techniques for GMB are demonstrated in the Grape Mealybug Spring Monitoring video.
Spring insecticide treatments can be an effective means to control GMB populations. An effective treatment is timed to occur when crawlers are present and somewhat exposed (on one year old wood and leaves) in early spring.
Download (53KB PDF)
Vine Mealybug Update
Feb 28, 2014
The results of the Napa County 2013 VMB Trapping Program are now available as downloadable maps on the Agricultural Commissioner's website.
All vineyard acreage in Napa County was trapped at a density of 25 traps per square mile, to more accurately detect VMB populations in new areas and to track resident populations. This program is supported by funding from the Napa County Wine grape Pest and Disease Control District.
A reminder that we are likely to have another "early" year for VMB. Sampling in Carneros on Jan 8, 2014 revealed mostly 1st instar nymphs (40.6%), but 2nd instar (21.2%) and 3rd instar (14.5%) nymphs were also found, as were females (12.7%) and ovisacs (10.9%).
Careful monitoring of VMB is highly encouraged. Large populations with overlapping generations can be very challenging to control. Multiple, early intervention strategies--targeted insecticides, mating disruption, parasitoid and predator releases--can keep VMB populations low. Rotation of insecticidal materials is also highly encouraged to decrease the potential for resistance to develop and to protect products for future use.
Download (63KB PDF)
Grape mealybug update
Feb 7, 2014
Early spring monitoring techniques for Grape Mealybug
This is a great time of year to develop and implement a grape mealybug sampling program. Crawlers of the overwintering generation should be hatching and moving to the spurs or canes and onto leaves as shoots grow.
Lucia Varela, UC IPM Advisor for the North Coast and Rhonda Smith, UCCE Viticulture Advisor, have developed a short video that describes the GMB life cycle, identifies targeted sampling areas, and demonstrates techniques for monitoring.
http://ucanr.edu/gmb spring monitoring video
Download (21KB PDF)
Grape mealybug update
Jul 17, 2013
We found 1st and 2nd instar GMB in clusters in Oakville and Rutherford. Follow newsletter link for details and photographs.
Download (5,361KB PDF)
Grape mealybug update
Jul 2, 2013
Emily and I checked GMB populations in Pope Valley today (HOT).
The most prevalent life stage was 1st instar GMB under the bark (one on a leaf). They were hatching from the eggs as we watched (COOL). We also found some eggs that have not hatched yet.
Because of the small size of the 1st instar nymphs, they can be difficult to see without a hand lens.
Download (54KB PDF)
Vine mealybug update
Jun 12, 2013
Sampled VMB at a vineyard in Carneros today. I found mostly 2nd instar VMB (63%) and 3rd instar VMB (22%). I also found a few females, one ovisac and one 1st instar.
Biological control agents (Cryptolaemus montrouzieri and Anagyrus pseudococci) have been released in this vineyard. I found evidence of parasitism (mummies and empty mummies) and 2 mealybug destroyer larvae.
Download (63KB PDF)
Grape mealybug update
Jun 11, 2013
Trap counts for our GMB monitoring traps in Oakville/St Helena show that the 1st GMB male flight is over.
We found mainly mature female GMB and ovisacs in visual surveys in Pope Valley vineyards on June 6.
Download (20KB PDF)
VMB Update for May 9, 2013
May 9, 2013
We are finding mostly 1st instar nymphs (crawlers) at a sampling site in Carneros. We also found new eggs in ovisacs. This is indicative of a new generation that is currently hatching.
We found most nymphs under the bark, and a few on the leaves. Other growers have reported finding some portion of the population on the leaves in Carneros.
Download (64KB PDF)
Grape mealybug report
Apr 23, 2013
Last week, on April 17, in Oakville, we found 1st and 2nd instar GMB under the loose bark of spurs and canes.
At this time of year, they are moving between the leaves and the loose bark of spurs and canes, as this generation develops.
Download (53KB PDF)
VINE mealybug update
Apr 16, 2013
We are finding all life stages of VMB at Carneros and Howell Mountain sampling sites. We found all VMB under the bark.
We found evidence of parasitism and predation at the Carneros site--both empty and full mummies, and mealybug destroyer beetle larvae.
Careful monitoring of VMB is highly encouraged. Large populations with overlapping generations can be very challenging to control. Multiple, early intervention strategies can keep VMB populations low. Rotation of insecticidal materials is also highly encouraged to decrease the potential for resistance to develop and to protect products for future use.
Download (53KB PDF)
Grape mealybug report for week ending April 5, 2013
Apr 9, 2013
We found 1st instar GMB in Oakville vineyards last week. All nymphs were found under the bark--either of spurs or canes. The shoots at all sampled vineyards were 1 inch or less in length, so we were not finding nymphs on the leaves yet. As the canopy grows over the next several weeks, the nymphs should move between the leaves and protected locations under the bark, as this generation develops.
Download (54KB PDF)
Open House: Male mealybug training session
Apr 3, 2013
Will you be using pheromone-baited sticky traps to monitor mealybugs? You can learn to identify the male mealybugs (grape, vine, and grass) in sticky traps at an informal, open house session.
April 18, 2013
9 am to 12 pm
UC Oakville Experimental Vineyard (1380 Oakville Grade Road)
Drop-in at your convenience, any time during the 9-12 time period. You can expect to spend 15-30 minutes learning to identify males. Please RSVP so that we can measure interest in this session.
Download (24KB PDF)
Vine mealybug report
Mar 18, 2013
We sampled a VMB population last Friday (15-Mar) in Carneros. Roughly 92% of our sampled individuals were 1st or 2nd instar nymphs, and all were found under the bark. We did not find any adults or eggs. We also found evidence of parasitism---both empty mummies and full mummies.
The somewhat explosive VMB populations in 2012 could be explained in part by (1) a diverse population earlier in the season than normal (in April 2012, all life stages were present), and (2) a late start on our treatments to target this population with overlapping generations. Thus, we should pay particular attention to VMB development in 2013, potentially targeting control practices for earlier in the season.
Earlier season insecticide sprays that target nymphs under the bark could be implemented. Also, the parasitoid, Anagyrus pseudococci targets mainly 3rd instar nymphs (some 2nd instars) for egg-laying. Female Anagyrus lay eggs at temperatures above 57.2 degrees F; Anagyrus larvae develop at temperatures between 52.9 and 96.8 degrees F.
Download (52KB PDF)
Grape mealybug report
Jul 20, 2012
The summer generation of the GMB is currently hatching at all of our sampling sites (Carneros, Oakville, and Pope Valley).
We are finding 1st instar nymphs on leaves, and under the bark of cordon and spurs. We also found one 1st instar on a berry.
There are still some eggs that haven't hatched, but >90% of the life stages that we found are 1st instar nymphs.
Download (57KB PDF)
Vine Mealybug Update
Jul 12, 2012
We found mostly VMB eggs and young nymphs at our Carneros sampling site. We found the eggs under the bark. Young nymphs (1st instars) are under the bark and on the leaves.
77.2% of the VMB population under the bark is eggs and 1st instar nymphs.
99.2% of the VMB population on the leaves is 1st instar nymphs.
We also found many mealybug destroyer larvae feeding on VMB eggs under the bark.
Download (55KB PDF)
Grape mealybug report
Jul 9, 2012
We are finding GMB eggs in ovisacs. We have not yet found hatched eggs or crawlers of the summer generation.
At our Carneros site, eggs are 91.4% of the sampled population; at our Oakville site they are 100%, and in Pope Valley they are 75% of the sampled population.
The remaining portion of the population at each site is female GMB. We also found one, 3rd instar nymph in Carneros.
Download (54KB PDF)
Grape mealybug update
May 11, 2012
The GMB population is mostly in the 2nd instar stage at vineyards in Pope Valley and Oakville. We are still finding some 1st instar GMB.
We found GMB under the bark (on canes and spurs) and also on the leaves.
Download (7KB PDF)
Grape mealybug report for week ending Apr 27
Apr 26, 2012
We continue to find mainly 1st instar GMB in vineyards we are monitoring from Pope Valley to Oak Knoll. We found all of our GMB under the bark of spurs and/or canes. We have not yet found GMB on the leaves, although we could expect to see them on the leaves with next week's warmer weather.
If you are planning to use an insect growth regulator (Applaud) to treat this overwintering generation of GMB, it will be important to make your applications while we still have young instars in the field (in the next couple of weeks).
According to Lucia Varela, UC IPM Advisor, these applications for GMB usually occur when there is between 6 and 10 inches of shoot growth--while we have mainly 1st and some 2nd instars in the population. It is not necessary to have all of the population exposed on the leaves, as there should be some activity of Applaud against a population on the canes or spurs.
Download (7KB PDF)
Grape mealybug update
Apr 6, 2012
We found GMB on spurs (spur pruned) and canes (cane pruned) in Pope Valley, Oakville, and Oak Knoll. We found a few hatched eggs under the bark of the trunk in Pope Valley. Otherwise, 100% of the live GMB that we found are 1st instars (crawlers).
Download (7KB PDF)
Grape mealybug report for week ending Aug 12, 2011
Aug 12, 2011
We continue to find mainly 1st and 2nd instar grape mealybugs.
In Pope Valley and St. Helena, we found GMB nymphs on leaves, in clusters, and under the bark of the cordon.
At our Oak Knoll sampling site, we did not find GMB nymphs on leaves or in clusters, solely under the bark of the cordon.
Nymphs will move into the clusters to feed and mature. Mature females will then return to the bark to lay eggs, which are the overwintering stage of GMB.
Download (8KB PDF)
Vine mealybug report for week ending July 29, 2011
Aug 1, 2011
We are seeing the overlapping generations typical of vine mealybug populations in the summer months.
All life stages are present at all of our sampling sites.
At the Carneros site, we found a few VMB on the leaves, but the majority of the population at all sites remains under the bark.
We are catching males in UC traps, and so are staff of the Ag Commisioner in their traps.
Download (8KB PDF)
Grape mealybug report for week ending July 22, 2011
Jul 26, 2011
Most of the summer generation of the GMB has hatched.
At our sampling site in Pope Valley, 69% of the sampled population was in the egg stage on July 11, 2011. By July 21, 2011, only 14% of the sampled population remained in the egg stage. A small percentage of the crawlers had moved out onto the leaves, but most remained under the bark on July 21, 2011.
At our St Helena sampling site, only 2% of the sampled population remained in the egg stage on July 22, 2011. The hatched crawlers were found principally under the bark of the arms and cordon, with a few remaining on the trunk. We also found one GMB 1st instar on the fruit, on a berry of a cluster that was in direct contact with the cordon.
As the summer generation develops, the nymphs will move into the fruit to feed.
Download (7KB PDF)
Grape mealybug report for week ending July 8, 2011
Jul 8, 2011
Crawlers of the summer generation are starting to hatch. We found 15 ovisacs: crawlers were hatching from 3 of these, but not from the other 12 ovisacs.
These are the very early stages of egg hatch. The hatched crawlers were still located under the bark. We did not find any GMB activity on the leaves or in the clusters. Eventually, nymphs of the summer generation will move to the fruit and foliage to feed.
Once the nymphs move to the fruit and foliage, this will be the appropriate timing for a contact or IGR insecticide application targeting the summer generation. Systemic insecticides should have already been applied for this generation.
We are seeing increasing evidence of activity of natural enemies: both predators and parasitic wasps. We found larvae, pupae, and an adult of the mealybug destroyer beetle (Scymnus). Unwarranted insecticide applications should be avoided to minimize disruption of natural enemy populations.
Download (8KB PDF)
Vine mealybug update for week ending July 1, 2011
Jul 1, 2011
VMB populations remain mostly synchronous at our sampling sites in St. Helena. The majority of the population is in the 1st or 2nd instar stage. We did not find any movement onto the leaves, although we may see some following the predicted warm weather. We are finding some evidence of parasitism at both sites.
VMB populations at our Carneros site are not as synchronous. We are finding mostly 2nd and 3rd instars, but a smattering of females, ovisacs, and 1st instars are also present. The Carneros population is also under the bark. We also found healthy populations of Argentine ant on the vines in Carneros with VMB.
Download (8KB PDF)
Grape mealybug update for week ending June 24, 2011
Jun 27, 2011
The GMB population is in the adult (female) and ovisac stages, at vineyards we are monitoring from Oak Knoll to St Helena, and into Pope Valley. Nymphs hatching from these ovisacs will move into the clusters to feed.
Last week we began to see more evidence of activity of biological control agents, both parasitic wasps and predators.
For those concerned about GMB as a vector of leafroll viruses, this will be the appropriate timing for insecticide applications.
Spirotetramat (Movento) applications may be most appopriate during this stage (egg development).
The appropriate timing for application of insect growth regulators (Applaud) is at or just after egg hatch. Insect growth regulators are most effective against young mealybugs (1st and 2nd instars).
Contact neonicotinoids (such as foliar applications of Clutch and Venom, Assail, Actara, and others) may be applied at or after egg hatch. Contact insecticides may be applied up to harvest (respecting pre-harvest intervals), although efficacy may be reduced after bunch closure when it is more difficult to contact mealybugs feeding in the clusters.
Organically registered materials also typically have contact activity, so are most appropriate after egg hatch, or during the young instar nymph stages.
Insecticide applications may disrupt natural enemies that attack GMB. Unwarranted insecticide applications should be avoided to conserve natural enemy populations.
Download (7KB PDF)
Vine mealybug report for week ending June 10, 2011
Jun 10, 2011
VMB eggs are hatching at all vineyards we are monitoring in Carneros and St. Helena.
92% of the VMB population at the block in Carneros is 1st instar;
60% of the VMB populations at the blocks in St Helena are 1st instar.
In Carneros, all VMB life stages were found under the bark. In St Helena, some 1st instars were found on leaves.
Download (7KB PDF)
GRAPE Mealybug report for week ending June 3, 2011
Jun 3, 2011
The first flight of male GMB has started in Napa County.
We are seeing mainly 3rd instars and females on vines in Oakville and Oak Knoll. We have not seen any egg-laying yet (no ovisacs found).
Download (7KB PDF)
Grape mealybug update
May 6, 2011
We found GMB on the leaves and the base of the shoots.
We also started seeing a sizeable population of predatory mites at our Oak Knoll site this week.
For growers concerned with GMB as a vector of grapevine leafroll virus, this is the first treatment window for insecticide applications. (This may not include Movento applications that require an expanded canopy for translocation).
Pesticide applications may disrupt natural enemies that attack GMB. Unwarranted applications should be avoided to conserve natural enemy populations.
Download (7KB PDF)
Vine mealybug report
May 4, 2011
Vine mealybug populations in Carneros are very synchronous right now. We found mainly adults. Most of the adults were laying eggs. We could expect egg hatch within a couple of weeks.
As the eggs hatch and crawlers emerge, that will be an appropriate window of insecticide applications (both chemigation and foliar applications). For information on insecticide efficacy for VMB visit http://ucanr.org/CESonomaMBcontrol
We also found many adults and egg sacs at the St Helena site. Some of the eggs have begun to hatch, and we also found crawlers at that site. At this St Helena site, development is slightly more advanced than in Carneros.
VMB development may vary by site. It is best to understand the populations in your vineyard to inform management decisions.
Download (7KB PDF)
Grape mealybug update
Apr 25, 2011
We sampled GMB at the end of last week (Apr 21, 22).
At our Oakville site, 100% of the GMB population was on the spurs. They were 1st and 2nd instars.
At our Oak Knoll site, 90% of the GMB population was on the spurs and 10% of the GMB population had moved onto the leaves. They were 1st and 2nd instars.
Insecticide treatments are most effective against exposed mealybugs (on the leaves). For growers concerned with GMB as a vector of leafroll virus, the first treatment window for foliar insecticide applications is approaching and will be optimal when the GMB are exposed on the leaves. (This does not include Movento applications, which require a more expanded canopy for absorption).
In vineyards where leafroll virus is not a concern, and GMB populations are not economically damaging, avoid unwarranted insecticide application to protect the GMB natural enemy complex.
Download (7KB PDF)
Vine mealybug report for Apr 15, 2011
Apr 19, 2011
VMB populations at St Helena and Carneros sites tended to be 2nd instars and Females.
Download (7KB PDF)
Grape mealybug report_11 Apr 2011
Apr 11, 2011
We scouted for GMB in Carneros, Oak Knoll, and Oakville.
We found 1st and 2nd instars. They were under the bark of the spurs, at the base of the spurs, and on the arms. We have not found any moving onto the leaves yet, but we expect this will occur soon.
We will be scouting for VMB in Carneros and St Helena on Friday, 15-Apr.
Download (7KB PDF)
Vine mealybug report
Mar 24, 2011
We sampled VMB in St Helena, 21-Mar-2011. We also planned to sample Carneros this week, but the weather did not cooperate.
All VMB were found under the bark, mainly on the trunk, from the soil line to the head.
Download (7KB PDF)
Grape mealybug report--18 Mar 2011
Mar 18, 2011
GMB are getting ready for spring!
At vineyards from Oak Knoll to St Helena, we found most of the population (92-100%) is in the 1st instar stage.
In Carneros, we found both 1st and 2nd instars (47% and 42%, respectively).
At all sites, GMB were found on the spurs; they are positioned to move onto the leaves soon after the vines break bud.
Weather permitting, we will report next week on VMB.
Download (7KB PDF)
Grape mealybug report
Mar 11, 2011
We sampled grape mealybug Feb 8-14, in Carneros, Oak Knoll, and St. Helena.
100% of population in Oak Knoll and St Helena vineyards were in the egg stage.
The majority (52.6%) of the population in Carneros was in the 1st instar (crawler) stage under the bark.
We will be out sampling again Mar 14-18, to issue another report the week of March 21.
Download (7KB PDF)
Welcome to the Vineyard Mealybugs newsletter
Feb 18, 2011
The purpose of this newsletter is to provide information on the life cycles of vineyard mealybugs in Napa County.
The two mealybug species of interest are the grape mealybug (Pseudococcus maritimus) and the vine mealybug (Planococcus ficus).
We will follow the development of these species through the growing season, and issue reports on the life stages found in vineyards of Napa County.
Download (7KB PDF)