Monitor vines, spurs and canes once during the delayed dormant season and once at bud break to check for cutworms, mealybugs, ants, thrips, 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 (example form—PDF).
How to Sample
- 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|
||Don't treat if less than 4% of the buds per location are damaged.|
|Pseudococcus mealybugs (grape, obscure, longtailed)||
||Treat if 1 out of 5 spurs is infested.|
||Treat during the delayed dormant period and again at bloom if vine mealybug is present. For heavy infestations, consider removing bark before spraying trunk and cordons.|
||Identify areas of concern for spring monitoring.|
||Identify areas of concern for bloom monitoring.|
||Treatment may be necessary if damage increases and temperatures remain cool.|