**The most commonly used # is x30, so in your case it is 136*30 =~4000 mites. This can be way off depending on the amount of brood in the colony and whether the colony is hygienic or not. The commonly quoted # is about 3000-4000 mites for economic threshould (worked out by Keith Delaplane in the Georgia/TN/SC area. so in your case, you should treat. Zach Huang www.msu.edu/~bees :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -- Visit www.honeybeeworld.com/BEE-L for rules, FAQ and other info --- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::