Neonicotinoids Made Easy: Pesticides, Pollinators and Water

A U.S. Geological Survey fact sheet, prepared with the National Park Service, explains pollinators, pesticides and the neonicotinoids that link them.

What are pollinators?

A pollinator is an animal — usually an insect — that helps plants make seeds or fruit by moving pollen from one part of a plant to another. Pollen sticks to pollinators that land on a flower to drink its nectar; when they move on to other flowers, the pollen they carry fertilizes them. This is pollination, and many plants need it to make fruits and seeds.

What are pesticides?

Chemicals used to kill or control pests, often on farms and in gardens. They are developed in laboratories and grouped by what they control:

What are neonicotinoids?

A type of pesticide commonly used in agriculture to protect crops from pests such as insects. They control pests effectively and help farmers protect their crops — but there is concern about their effect on other organisms, including pollinators, and bees above all. Because some studies indicate they can harm bees and other pollinators that many crops depend on, research continues into their use and their effects on the environment.

Why bees are the worry

The main concern with neonicotinoids and other pesticides is that they can harm bees by reducing their ability to pollinate, through:

• direct poisoning
• disorientation
• weakened immune systems
• reduced reproductive capacity

Bees pollinate many of the crops people rely on for food. Their decline could mean lower crop yields and less food overall.

How they move through the environment

1. On the crop: pesticides are sometimes sprayed on crops, and the coating on many planted seeds often contains neonicotinoids.
2. Into pollinators: bees and other pollinators can be exposed through pollen and nectar, from either sprays or seed coatings.
3. Into soil: soil can be exposed to pesticides and neonicotinoids.
4. Into water: from there they can move into groundwater and surface water.

Sources

Based on Shipra Shukla and Elias Tejeda, Neonicotinoids Made Easy, USGS Fact Sheet 2024–3014, version 1.1 (June 2025), U.S. Geological Survey; a work of the United States government in the public domain. The sheet is printed in English and Spanish; this page follows the English, from its PDF. Its illustration of these routes is made of licensed stock photographs and is not reproduced. The sheet's "National Parks Service" is corrected.