Left over insecticide?

I recently had to battle some new caterpillars on my lettuce so I purchased a bottle of Bacillus Thuringiensis that needed to be diluted. Once diluted it says to use the mixture in 24 hours but it made waaaay more than I needed. I can’t dump it down the drain and I can’t use it up so what do I do with it now? Any idea how I am supposed to safely dispose?