Ladybugs will appear about every 45 min to 1 hour. You have to look around the map to find them. They will be on their backs. To help them, just simply tap on them and they will fly away. If you do the time glitch, just set the clock ahead 4 hours, then go back into game and help the ladybug. Keep repeating the glitch as many times as needed. If you use the time glitch, make sure you do not unlock your achievement in the future.
Note: There is a glitch that can cause the Ladybugs to stop appearing in the game. If this happens to you, please check your village very carefully and consult with this thread. If you do not find any in your search and they still do not show up, you will eventually need to start the game over. Please see the Roadmap and this thread for information on what to do in this situation.