neem oil is pressed from neem cake,they are the same,neem cake is best for amending your soil and keeping some of the bug life out,but doesnt completly fix all,if you are for sure there are larvae in your green house,use capt jacks from any box store ,water it in with a sprayer and give it a good wetting,stand back for a few minutes and any worms such as catipillar,leaf cutters and such will come right to the top to get some were as they die,far as the larvae a couple of spraying as mention above about 3 or 4 days apart will put a good can of whoop ass on them,i cant say it will take all of them but it put a damper on them for sure,any product with perithan think that how you spell it works,my fav is
azamax,i spray
azamax one day 3 days later capt jacks ,then
azamax again,my last spray is a seriouse pepper spray i make and it will gas your ass,with all this said i would only do this if no plants were growing and i had at least a month before planting again,if your plants are growing do the same a week apart,it a cycle for them and in order to get them all you have to keep at them for there life cycle,goggle there life cycle and you will know for sure,me i wouldnt spray but twice and let plants recover,also i mention that if you have flower on plants like squash ,potato and such ,dont get it on the flowers they wont pollentate if you dig
