BioActive Supply's Aspen Excelsior is our recommended medium for fruit fly cultures!
Aspen Excelsior also known as wood wool and American moss is a renewable material that is used for fruit fly cultures. This Material provides fruit flies a place to live on, mate, and lay eggs. This Product compared to alernatives such as coffee filters provide higher fruit fly yeilds and more stable cultures. 
Aspen Excelsior is a 100%natural and Biodegradable material that is sure to improve your fruit fly cultures!
*The BioActive supply Aspen Excelsior will provide enough material for ten fruit fly cups!