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How to Manage Pests
UC Pest Management Guidelines
Grape
Delayed-Dormant and Bud Break Monitoring
(Reviewed 6/06,
updated 6/06)
In this Guideline:
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Monitor vines and spurs once during the delayed dormant season and once
at bud break to check for cutworms, mealybugs, ants, and mites. Spurs are
one-year-old canes that were pruned back to 1 to 2 buds at pruning.
Use monitoring form
with detailed treatment threshold information.
HOW TO SAMPLE
(View photos of pests
for identification.)
- On a warm day (65°F or
above), monitor 20 vines by looking at 5 randomly selected vines per quadrant
of the vineyard. For the best estimate of pest distribution, monitor fewer
vines in more locations. Be sure to include those areas, however, where you
have noticed pests in the past.
- Monitor
vines following the guidelines below. For spur monitoring choose a spur on the
basal portion of a cordon closest to the crown.
- Record
your observations on a monitoring form.
PROCEDURE AND TREATMENT THRESHOLDS
| Pests |
Monitoring procedures |
Treatment threshold |
| cutworms |
Examine 5 buds for damage (hollowed buds).
If damage is present, look for cutworms under bark, on cordons, trunk, and at soil level. |
Don't treat if less than 4% of the buds
per location are damaged.
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| pseudococcus
mealybugs (grape, obscure, longtailed)
|
Look for crawlers under loose bark at the
spur tip.
Along Central Coast, also look for more mature obscure and longtailed mealybugs at base of spur, under bark. |
Treat if 1 out of 5 spurs is infested. |
| vine
mealybugs
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Look for
nymphs and females under bark at graft union, in old pruning wounds in the
trunk, and below the base of the spur (old remnant egg sacs may be found). In sandy soils, look at soil level and at roots. |
Treat during the delayed dormant period
and again at bloom if vine mealybug is present. If treatment is needed, remove bark before spraying trunk and cordons. |
| ants |
Look for ants. If found, look more closely for mealybugs or European fruit lecanium. |
Identify areas of concern for spring monitoring. |
| mites |
Look under loose bark on spur tip for orange overwintering form of Pacific or Willamette spider mite. |
Identify areas of concern for bloom monitoring. |
| thrips |
Open shoots or gently tap buds over white paper to check for thrips. |
Treatment may be necessary if damage increases and temperatures remain cool. |
![[UC Peer Reviewed]](/IMAGES/logo-ucpeerreviewed.jpg)
UC IPM Pest Management Guidelines: Grape
UC ANR Publication 3448
General Information
W. J. Bentley, UC IPM Program, Kearney Agricultural Research Center, Parlier
L. G. Varela, UC IPM Program, Sonoma Co.
F. G. Zalom, Entomology, UC Davis
R. J. Smith, UC Cooperative Extension, Sonoma Co.
A. H. Purcell, Environmental Science, Policy and Management, UC Berkeley
P. A. Phillips, UC IPM Program, Ventura Co.
D. R. Haviland, UC IPM Program, Kern Co.
K. M. Daane, Kearney Agricultural Research Center, Parlier
M. C. Battany, UC Cooperative Extension, San Luis Obispo Co.
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