The allusion comes on page 151 with the mention of "God," "Moses," and the "plagues." The meaning of the allusion is directly explained in the text, so I encourage you to find it, read it, and see what you get out of it.
The background information necessary to understanding this allusion is that it is a direct reference to the Exodus story of Moses leading the Egyptians out of slavery in Egypt. God sent 10 plagues on Pharoah and his people, one of which included swarms of locusts. Additionally, a key quote from the story (well known from movies and songs, not just the Biblical story) is "Let my people go." Lily, here, remembers the first night the bees came into her room. She thought of them then like a plague that God had sent to her father, as if to say, "Let Lily go."
Here at August's house, however, she is finally free. Consider the difference these bees hold for her now, as opposed to the first encounter she had with them.