Wasps get a good and a bad rap. Initially they prey upon other arthropods. Many of these, bugs, caterpillars, flies and others, are considered garden pests. These they chew up to feed their larvae back at their nest.
Unfortunately, when wasp colonies stop breeding new workers in late summer, the existing workers search for the sweeter things in life. These are often supplied by humans, especially in the shape of soft drinks and fruit.