Neonicitinoids include products such as imidacloprid (Merit, Marathon, various homeowner products made by Bayer), dinotefuran (Safari), acetamiprid (TriStar), and thiamethoxam (Flagship). All the chemicals in this group are systemic and move to plant issue once applied. This includes nectar and pollen. These products have been under scrutiny lately due to their negative effects on pollinators. See this report.
Recently there was a large bee kill in Oregon apparently due to misapplication of a neonicotinoid to a flowering linden tree. Labels typically state “Do not apply to flowering plants or when pollinators are present” or something similar. In response the Oregon Department of Agriculture has temporarily restricted use of dinotefuran while it investigates the incident. More information about this incident is in a recent article.
This points out the importance of correct use of these (and all) insecticides by professionals and homeowners.