Pesticides can be classified based upon their biological mechanism function or application method. Most pesticides work by poisoning pests. A systemic pesticide moves inside a plant following absorption by the plant. With insecticides and most fungicides, this movement is usually upward (through the xylem) and outward. Increased efficiency may be a result. Systemic insecticides, which poison <answer>pollen and nectar in the flowers</answer>[citation needed], may kill bees and other needed pollinators[citation needed].
Which parts of a plant do systemic pesticides generally attack?
pollen and nectar in the flowers