Currently I am using a small hive beetle trap with a tray that I've been filling with vegetable oil. It has been working pretty well, but I'm looking to reduce cost as I am replacing vegetable oil in 4 hives every two weeks which is an expense I would like to reduce. I have a friend who has "sludge" oil from making bio diesel. This sludge oil is the oil that is left over after he has processed his biodiesel. The oil is basically old vegetable oil that he was given from commercial fryers. Is this a safe alternative to buying and using new vegetable oil? Has anyone done this before? Or what are ya'll using? Just looking for a cheaper method.
Thank you very much,