The larger wasps, like paper wasps, do cintrobute to some extent to pest control in a garden. However their smaller cousins, the parasitic wasps, are even more important. Aphids are generally not food for large wasps, but they can be the exclusive food for some very small parasitoid wasps. Even though they are rarely seen, except by the keenest observers, these wasps do most of the heavy lifting in garden pest control. They are the ones we want to protect when choosing what and where to spray.