UF/IFAS
Okeechobee County Extension Service
458 Highway 98 North
Okeechobee, FL 34972-2578
Phone: (863) 763-6469
E- mail: dfculbert@ifas.ufl.edu
| Quick Links: l References |
September 11, 2006
Feature Article - for release the week of September 17, 2006
Dan Culbert - Extension Horticulture Agent
BIOPESTICIDES IN YOUR FLORIDA YARD
Local homeowners that deal with pests in the landscape are often concerned about the use of pesticides in their Florida Yards. During a recent conference, UF Extension Plant Pathologist Monica L. Elliott presented a few ideas on a kinder, gentler way to manage unwanted pests without sacrificing our delicate environmental quality. Today’s column shares some of her thinking on the use of biopesticides.
The modern answer to landscape pests is called Integrated Pest Management. IPM is a way to deal with pests that uses pest identification, and monitoring, followed by decisions to use multiple approaches to reducing pest populations. Cultural methods such as using pest resistant varieties, selecting appropriate plants and management techniques are coupled with traditional chemical controls or biological controls to manage a pest problem.
All too often biological controls are promoted, even by scientists, as the ultimate problem solver. They are not. They are simply one part of the complex puzzle - another weapon that can be used if a battle is needed.
Biological control suggests that some kind of other creature is involved in controlling a targeted pest. But does that organism have to be alive? Can we figure out how Mother Nature works and have it help us out? Why does the word "pesticide" always have to be lumped with the "bad guy"? These are some of the topics that relate to Biopesticides.
Using Nature as a blueprint
It is important to realize that there are safe chemical pesticides. The trend in the pest control industry is to look to nature for clues for chemical pesticides. Biologically derived pesticides are synthetic compounds whose chemistry is based on natural products.
A
good example of biologically inspired synthetic pesticides
is the strobilurin group of fungicides. The active
ingredients are based on natural compounds produced by a
fungus that decays wood. However, when the natural
compounds tested under field conditions, they proved to be
impractical because they broke down when exposed to
sunlight. These natural products inspired the stable
synthetic versions which were invented.
Biopesticides are natural products where there is no chemical synthesis involved. Since they are pesticides, they are regulated by the Biopesticides and Pollution Prevention Division of the U.S. Environmental Protection Agency (EPA).
Types of biopesticides
There are three types of biopesticides - biochemical, plant, and microbial.
Biochemical biopesticides are naturally occurring chemicals that control pests by a non-toxic mode of action. The most common examples are pheromones - chemicals that insects produce that regulate certain kinds of activity, such as molting or egg-laying.
Plant biopesticides are substances that plants produce from genetic material that has been added to the plant. The insertion of the Bacillus thuringiensis (Bt) endotoxin genes into crops like corn, cotton and potato to control insect pests are well known examples.
Microbial biopesticides contain a naturally occurring or genetically altered microorganism or its product as the active ingredient.
Examples of Biopesticide Products
Microbial biopesticides examples are available if you know to ask for them. At the end of 2001, there were approximately 195 registered biopesticide active ingredients and 780 products. These products do not permanently establish in the environment. Here are some examples of commercially available biopesticides:
-
"Bt" insecticides such as DipelTM are derived from the bacterium Bacillus thuringiensis. This is an example of
a
product that is composed of a dead microbe and/or the
product that it produces. When you apply Bt
insecticides, you are applying a toxin produced by the
bacterium. The endotoxin has been separated out from
the rest of the products the bacterium produces and
from the bacterium itself. When the targeted insect
(such as caterpillars or mosquito larvae) eats this
toxin, it is killed. One of the main problems with Bt
insecticides is that the toxin is readily broken down
by sunlight. This is why it is best to apply the
product just before dark. -
DiTera is a product that is composed of the dried fermentation residues of a fungus, Myrothecium verrucaria. It is labeled for insect and nematode control. The fungus is no longer living. But, unlike the Bt insecticides, essentially everything produced by the fungus during fermentation is used to formulate the product.
-
An third example of a biopesticide product composed of a living microorganism is the fungicide RootShield Home & Garden. It is composed of the fungus Trichoderma harzianum. This product may control soilborne fungal pathogens in a number of ways, such as production of a toxin or competition for food or root sites.
Biopesticides must be registered
If
a product composed of microbe(s) claims to directly
control a pest, it must be registered
by the EPA as a pesticide. 
If
a living microbial product only claims to improve plant
health in general, without mentioning specific pests, the
product does not have to be registered by the EPA. These
products are often referred to as inoculants.
Registration by EPA indicates the product has been determined to be safe, when used as labeled, for humans, non-target organisms (e.g., fish, honeybees), and the environment in general. Non-registered products have not undergone a safety evaluation. EPA does not evaluate any product for efficacy.
I’ve placed more information on our Okeechobee web page, http://okeechobee.ifas.ufl.edu. If you need additional information on Biopesticides, please email us at okeechobee@ifas.ufl.edu or call us at 863-763-6469. Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, and visit our Okeechobee County Master Gardeners from 1 to 3 PM on Tuesday afternoons.
-30-
Trade names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin. Florida Cooperative Extension Service / IFAS / University of Florida. Larry A. Arrington, Dean Last update: 09/18/2006 . This page is maintained by Dan Culbert
Culbert, D.F. Biopesticides in Your Florida Yard. Vero Beach Press Journal, 9/9/01. http://okeechobee.ifas.ufl.edu/News%20columns/Biopesticides.htm
Leppla, Norm. Biopesticides and Biorationals. UF/IFAS IPM website. 2003. http://ipm.ifas.ufl.edu/applying/tactics/pesticides/biopesticides_biorationals.htm
Reilly, Sheryl. What are Biopesticides? Washington: US EPA, 5/2006. http://www.epa.gov/pesticides/biopesticides/whatarebiopesticides.htm
Weinzierl, R., Henn T., and Koehler, P. Microbial Insecticides (UF/IFAS bulletin ENY-275). Gainesville: Florida Cooperative Extension Service, 6/2005. http://edis.ifas.ufl.edu/IN081