Super-useful, lemongrass essential oil is what is used to lure swarms to bait hives. It mimics the pheromone that scout bees release when looking for a new home and has been said to double your chances at luring a swarm to a hive or trap. Just put a couple drops of the oil inside the entrance of your hive and wait! You can also refresh the oil weekly to keep the scent fresh.
If you've already got a hive without bees, you may as well bait it with lemongrass and see what happens, while you pursue other avenues of obtaining bees (catching a swarm, buying a package, etc.). The 1 ounce bottle of oil will last for years to come!