A bee's life is but short...many workers die before they have reached even that age.
The quotes at the beginning of each chapter in The Secret Life of Bees serve to foreshadow events that will happen in the chapter, as well provide definition and clarity to the chapter in terms of the recurring bee analogy used throughout the book.
This is the chapter where May commits suicide. The quote at the beginning of this chapter then suggests that May was a "worker bee" who died before her time was up because she was "threatened by all kinds of dangers," in life. The question presented, therefore, is what dangers existed that May should take her own life.
After the suicide of her twin sister, May displays a sensitivity toward others and toward life unlike any of the other characters. She is easily upset, evidenced by her tears while watching the news. As a result, the other sisters attempt to protect her from bad news. Even so, she frequently retreats to her "wailing wall" in order to sooth herself. It is the news of Zach's arrest which finally puts her over the edge this time, causing her to drown herself in the stream.
The quote at the beginning of this chapter not only foreshadows May's death, but pays her a tribute of honor, suggesting that she had a very specific place and role in the "hive" of August's house, and she died doing what she was meant to do.