If the ratio for dilution on my horse fly spray is 8 oz in 50 gallons of water how much of the concentrate would I use in a 44 oz container?

1.65 ml per 44 oz would be a good ratio. However to get this that accurate you need to use an insulin syringe to get the ml broke into tenths. A ratio of 2 ml to 44 oz is not going to hurt anything. Also if you will put a little white vinegar in the mix instead of a couple of oz of water it will last longer. Shepherd 564