Per the product label, you can mix Safari 20SG with a surfactant, but it may not be very helpful for woolly adelgids in particular since they are mostly controlled by ingesting the active ingredient rather than by contact:
Tank mixing with a surfactant may improve control of pests such as whitefly, mealybug and scale. Confirm plant safety of tank mix in small area before using on a commercial scale.
Safari can be applied as a basal trunk spray as gives instructions on page 15 of product label for doing so.