By Heidi Lindberg
Biopesticides are classified into three main categories: biochemical, microbials and plant-incorporated protectants.
An increasing number of greenhouse growers in Michigan are discovering biopesticides can be used in conjunction with commercially purchased natural enemies as a part of their integrated pest management (IPM) programs. Biopesticides offer numerous advantages to growers, including lower risk to employees, minimal (or no) re-entry and pre-harvest intervals, and compatibility with biocontrol programs.
In fact, a recent survey of Michigan floriculture growers revealed all of them had used at least one biopesticide in conjunction with their biological control program. While greenhouse growers are now using biopesticides, they often have questions such as: What is a biopesticide? How are they different from each other? Which one should I use?
Biopesticides are pesticides derived from natural materials, including animals, plants, fungi and microbes. The Biopesticides and Pollution Prevention Division of the Environmental Protection Agency, which registers biopesticides in the U.S., classifies classified biopesticides into three categories: biochemical, microbials and plant-incorporated protectants.
Biochemicals
Biochemicals are derived from naturally occurring substances such as plant extracts. This includes insect repellants, insect attractants and repellants, pheromones, and non-pest management class—plant growth regulators.
Examples
- Azadirachtin (broad-spectrum insecticide).
- Capsaicin (compound from chili peppers) (broad-spectrum insecticide, nematicide and fungicide).
- Clove, rosemary and peppermint oil (broad-spectrum fungicide).
Microbials
Microbials are products containing micro-organisms or their fermentation by-products.
Examples
- The bacterium Bacillus thuringiensis for use against caterpillars.
- The fungus Beauveria bassiana for use against whiteflies, aphids and thrips.
Plant-incorporated protectants
Plant-incorporated protectants are pesticidal substances produced by plants as a results of genetic manipulation. There are no plant-incorporated protectant compounds registered for use in greenhouses.
As of April 2016, there were 299 active ingredients in biopesticides registered with the Environmental Protection Agency (EPA). However, only 40 are labeled for use in greenhouses.
Read Part 2 of this Michigan State University Extension article, “Biopesticides for use in greenhouses in the U.S.,” to see our list of these compounds and the products available for greenhouse use.