3 Major Classes of Biopesticides and Their Advantages

According to the EPA, Biopesticides are naturally occurring substances that control pests.
These substances fall into three major classes:

 

  1. Biochemical pesticides are naturally occurring substances that control pests by non-toxic mechanisms. Conventional pesticides, by contrast, are generally synthetic materials that directly kill or inactivate the pest. Biochemical pesticides include substances that interfere with mating, such as insect sex pheromones, as well as various scented plant extracts that attract insect pests to traps. Because it is sometimes difficult to determine whether a substance meets the criteria for classification as a biochemical pesticide, EPA has established a special committee to make such decisions.
  2. Microbial pesticides consist of a microorganism (e.g., a bacterium, fungus, virus or protozoan) as the active ingredient. Microbial pesticides can control many different kinds of pests, although each separate active ingredient is relatively specific for its target pest[s]. For example, there are fungi that control certain weeds and other fungi that kill specific insects.
    The most widely used microbial pesticides are subspecies and strains of Bacillus thuringiensis, or Bt. Each strain of this bacterium produces a different mix of proteins and specifically kills one or a few related species of insect larvae. While some Bt ingredients control moth larvae found on plants, other Bt ingredients are specific for larvae of flies and mosquitoes. The target insect species are determined by whether the particular Bt produces a protein that can bind to a larval gut receptor, thereby causing the insect larvae to starve.
  3. Plant-Incorporated-Protectants (PIPs) are pesticidal substances that plants produce from genetic material that has been added to the plant. For example, scientists can take the gene for the Bt pesticidal protein and introduce the gene into the plant's own genetic material. Then the plant, instead of the Bt bacterium, manufactures the substance that destroys the pest. The protein and its genetic material, but not the plant itself, are regulated by EPA.

 

There are advantages to using biopesticides in that they are less toxic than conventional pesticides and generally affect only the target pest and closely related organisms.  In contrast, the use of conventional pesticides has been known to adversely affect other organisms such has insects, mammals and birds. Biopesticides are often effective in very small quantities and decompose quickly which results in lower exposures and an avoidance of pollution problems. They can often be used as a component of Integrated Pest Management (IPM) programs, and can greatly reduce the use of conventional pesticides, yet still produce a high crop yield.

In 1994, the EPA established the Biopesticides and Pollution Prevention Division in the Office of Pesticide Programs to facilitate the registration of biopesticides. This division promotes the use of safer pesticides, including biopesticides, as components of IPM programs. The division also coordinates the Pesticide Environmental Stewardship Program (PESP).

Since biopesticides tend to pose fewer risks than conventional pesticides, EPA generally requires much less data to register a biopesticide than to register a conventional pesticide. In fact, new biopesticides are often registered in less than a year, compared with an average of more than three years for conventional pesticides.

For more information on this subject and more, you may contact

Ombudsman, Biopesticides and Pollution Prevention Division (7511P)
Office of Pesticide Programs
Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, D.C. 20460

(source: EPA.GOV)

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Plants in Distress: A Beacon for Birds

Researchers at the University of Delaware have recently found that agricultural plants send out sensory volatile cues that alert organisms in the area (such as birds) that they are in need of help. Previous research has shown that this occurs in ecosystems such as forests. These “signals” are sent when plants are under siege from insects. With a little Play-Doh and orange colored pins, they are seeing the potential for growers to defend their crops.

Play-Doh "larvae" were distributed onto plants around a volatile dispenser that released the odor and recorded how many bird pecks were on the larvae closer to the volatiles versus the organic solvent dispensers. The results were clear: There were significantly more attacks on the larvae closer to the volatile dispenser.

It has been known for years that parasites and predatory insects respond to the damaged plants that release volatiles. With this new evidence of birds using the same cues, it allows a better understanding of their behavior. This information will be crucial when creating pest management programs. Interestingly, when scientists compared the number of pecks on the larvae attached to the volatile dispenser and the number of pecks on the surrounding plant larvae there was virtually no difference. That means the birds are smelling the volatiles and when it gets close to the damaged plant it visually searches for the insects.

It has been a longheld belief that birds were unable to smell. However, this research indicates that they are smelling the volatiles and then coming in closer to visually locate their prey. Birds lack certain anatomy to be able to smell yet somehow they are able to sense the volatiles emitted by the plant. Researchers will be testing to see which species of birds have this capability using essentially the same experiment as above.


Pesticide Professional Continuing Education

Online state-approved video continuing education courses are available 24/7.

 

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