Where in the Bible does it talk about the end of the world involving insects?
Nowhere does the Bible talk about the end of the world involving insects. In fact, that would be difficult since the end of the world would be the end of insects as well. “But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up.” (2 Peter 3:10)
There are some passages in the Old Testament prophecies that may involve insects in God’s punishments of the nations at the time. Most notable among these is Joel 2, which many interpret as a description of a plague of locusts.
Revelation 9:3 also talks of locusts. Since the book of the Revelation is about the Roman Empire’s persecution of the church, and not about the end of the world, this scripture wouldn’t apply to your question. Additionally, the locusts here are symbolic and probably not a reference to real insects.