yea spinosd will work but there is a better alternative, go buy sum predator nematodes and water em into ur super soil, it wont effect ur microlife and will continue to take care of any soil born pest, the nemdotes eat the larvae and adults, they attack almost all soil dwelling insects, also if u have pets and are worried about fleas or ticks this summer u can water sum nematodes in ur lawn and they will go tho eating all the larvae, so not only can they help the plants but they can help u as well, i live in a area where there is alota wildlife and alot insects that crawl around and can be dangerous or agitating for my dog so i water my property wit nematodes every spring and summer, anyway give the nematodes a whirl before adding anything else, it will take em bout a week to get established an a hold on the problem but once they're in there they work wonders