As RayR mentioned, you can dissolve it in water and apply it. Just make sure you put it through some cheesecloth or a sock or a coffee filter, otherwise it will clog up your sprayer. Very effective this way. If it rains you have to reapply.
BT works well on the guys you mentioned.
And Aphids, well, they're just awful. Neem/DE/soap/oil all can help control them, you just have to do it over and over. This might help:
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7404.html