This can be unlocked fairly easily during Story Mode. Starting from your first encounter with the yellow killer wasps on "Duscae - Trail" and the red wasps later on, you can lead enemies around while only deflecting their stingers (use
when the screen zooms in). By pointing the left thumbstick towards an enemy, you can choose where to deflect the stinger, so keep the wasps alive as long as possible while you kill everything else.
I unlocked this about halfway through the 5th level, "Duscae - Deep Forest".