We're gonna drag these Beetles up along the food chain with us. 

Meet with the bees again. After all, we planted these berry bushes "for them." They're a mutual investment. See if they would be willing to buzz by to inform us when these threats are coming, so that we might be able to marshal our new forces to better protect them.

Alternatively, we could evolve a big, fat, round variant of the drones the same color as the berries and full of poison and sticky fluid. Position them on the most tempting looking clusters of berries and let these giant monsters devour them. See if we can teach them that berries are dangerous.