The biggest issue now has been the several days of heat and the stress that it is placing on the vines (including the possibility of scald mentioned within the past few days). Make sure you keep the vines well watered during periods like this until the heat breaks. Some vines have been showing evidence of vein whitening (see photo). Evital applications were made in the fall and likely, the weather conditions have stressed the vines and caused these symptoms to show. A couple of small fertilizer applications (foliar feed with some micronutrients may be good) may help the vines to recover.
Keep in mind, to apply the equivalent of the highest label rate of Callisto (8 oz/A), use just 1.6 tsp per gallon (this assumes an application rate of 30 gallons of water per acre, which is very reasonable for most ground applicators); 1.6 tsp equivalent to about 0.27 oz. The maximum amount of NIS should be 1.9 tsp (0.32 oz) per gallon or 2.5 TBsp (1.3 oz) crop oil; you can use about 2 oz of Poast per gallon of water to deliver the high-end rate of a 1.5% solution. If this combination is working and there are no application (phytotoxicity) issues, then this is good news. Just be sure your recipe keeps to the rates permitted by the label.
From the Entomology Lab: Keep in mind that Belay is only being recommended for cranberry weevil; it is a better choice than Actara for summer weevil management. You can only apply a total of 19.5 oz/A of Delegate per season. Reminder for those delivering to Ocean Spray: No Sevin (carbaryl) applications can be made after August 1.