Ok so they are probably flightless, which means they can revert to flighted at a certain temperature ( you'll have to google as I dont recall ). As for making new cultures, you'll need containers, culture media, yeast, and excelsior or coffee filters and distilled water ( doesnt have to be RO, boiled is fine ). The media is mixed with water, usually in a ratio of 1:1, allowed to solidify, a few grains of yeast are sprinkled on top and the excelsior ( basically hard shredded paper like material for the flies to crawl on ) is placed in. Then some flies are shaken in, the container is closed and left in a warm spot and within about a week you will have a teeming new culture if everything goes well. You can buy the stuff at the website I posted earlier or google around for others.