Lammbock (2001) on Netflix

Plot summary

Kai and Stefan Becker own a gourmet pizza delivery business, a front for the cannabis they grow and sell. Stefan, whose father is a judge, is in the final stages of law school at his father's request. When the two visit their outdoor cannabis crop, they find aphids destroying the plants. At a head shop they meet Achim, who says he knows how to get rid of the pests and hands them a container of Aphidoletes aphidimyza. The two debate bringing him to the crop.