Adult Audience:  Audience should have an above general understanding of science-and to a lesser degree Biology / Insect metamorphosis with an understanding of Agricultural Food production and associated pest and weed management. OBJECTIVES After completing this lecture, participants should be able to; Describe and explain some of the positive and negative agricultural impacts attributed to insects; bacteria ; fungus; disease and some of the historical control methodologies.  Explain the need and potential for biological control and its application and role in sustainable, diverse and safe agricultural environment  Explain classical bilogical control with specific emphasis to the roles of natural enemies - notably-Predators; Parasitoids; Pathogens and Weed Feeders

Recent news headlines in the Palm Beach Post Times of February 6, 2000, highlighted the cooperative research effort between a local Okeechobee, Florida High School senior , who is the granddaughter of a long time area rancher/farmer and the University of Florida IFAS Center-Immokalee . The showcase of this research was the reporting of findings relative to continual research efforts to find a methodology to eradicate exotic plant species-in this case Tropical Soda Apple. Through a series of continual experimentations, the research has shown that by spraying the targeted species with a mix of bacteria and herbicide the end result leads the researchers to believe with a high degree of confidence that they are on the right track to better manage this invasive plant. Through this management process, the intent is to reduce the amount of herbicide use. This methodology will reduce the costs of chemical control as well as lessening the amount of chemicals put onto and into the land. By reducing the area covered by this invasive plant, more land has the potential to be returned to agricultural use.

Over the past years, much media text has been given to the need for all of us to be more involved and more aware of the need for a better environment. Often highlighted, is the continual pressure to reduce the amount of chemicals that are used to control pests and diseases, while still trying to maintain a balance and goal to produce food and feed the world's population. Much has been said, often times jokingly, about insects outsurviving the human species in the event of a nuclear war, due in large part to their continual genetic adaption to chemical sprays and changing environments. Most of us have been raised with some understanding that some insects-perhaps a few -- are good, such as the Ladybug. There also seems to be a general understanding that worms are good for something other than to be attached to a fishhook. For the most part, however, the proliferation of pest control companies throughout the residential areas and the ever presence of spray trucks and planes on agricultural lands, still lends credence to the populous thought that the only good bug-is a dead bug! The row after row of chemicals stacked on shelves at local home supply stores does have a tendency to paint a picture that most insects; bacteria and fungi are better off eliminated, with prejudice.

This presentation through a combination of written words and information linkages with photos and graphs will attempt to shed a more positive light on natural methods of control and highlight the positive impacts these methods can have to agriculture and the food production environment.

Before we venture too far into the relationships of biocontrol, diversity, and food production, it is important to understand some of the general information relative to what biodiversity -agroecosystems-and agrobiodiversity mean.

Biodiversity and the detailed knowledge about its role in our environment, have allowed farming systems to evolve through the years. While some may be surprised to see the use of the word diversity and agriculture in the same sentence and not note it as an example of an oxymoron, agriculture is based on a diverse biological foundation and is comprised of a variety of managed ecosystems, known as agroecosystems. Agrobiodiversity is a basic principle of worldwide farming systems and includes many types of biological resources. The World Resource Institute's articles about Sustainable Agriculture notes agrobiodiversity as a basis for production and survival.

This site http://www.wri.org/wri/sustag/iba.html notes the general benefits of Agrobiodiversity. Of special interest in this reference is the Conceptual view of Agrobiodiversity on page 2, and the general benefits associated with Agrobiodiversity noted on page 3 of this particular article.

AGRICULTURE AND GENETIC DIVERSITY

In all organisms that reproduce sexually, each individual member contains a mix of genes. This mix is known as genetic diversity and it is through this species variation that populations can adapt to changes in the environment. This can be both good and bad. When a species loses too many individuals- it becomes less diverse and the result is a uniform genetic composition. The more uniform or homogeneous the genes the less adaptable that species is to environmental changes. A benefit of genetic diversity is that it hardens the gene line to hold off pests and diseases which may have gone through their own genetic hardening and poise a continual threat. More than 400 species of crop pests have developed resistance to one or more of the pesticides used to control them. In the case of the corn crop failure in 1970, the United States lost 15 percent (1 Billion $$'s) worth of corn to a fungus which up to that time was not present in high levels. However, as a result of genetic uniformity, the plant was essentially defenseless to the fungus.

As mentioned, pesticides are also overtaken by genetic evolution in the targeted species and as a result offer only a temporary deterrent to pests. While 400 species of pests now resist more than one pesticide-the proportion of crops lost in the US to insects has doubled since 1940's to 13 % with some estimates closer to a top end range of 20%. Wild-also referred to as natural relatives of crops have contributed to the improvement of that plants resistance to diseases -fungus-drought and heat. The number of genes range from about 1,000 in bacteria; to 10,000 in some fungi and 700,000 in flowering plants and some animals

The World Research Institute articles on Biodiversity highlight the value of genetic diversity for agriculture and discuss genetic engineering; diversity and livestock breeding; forest species aquaculture as well as problems with genetic uniformity.
http://www.wri.org/wri/biodiv/agrigene.html    http://www.wri.org/wri/biodiv/gene-div.html

An additional point of interest to the reader is the risks associated with High - Yielding Crop Varieties.

AGROBIODIVERSITY LOSS:  CONFLICTS AND EFFECTS

Increased Vulnerability to Insects Pests and Diseases

 Homogeniization of species increases their vulnerability to insects, pests and diseases. This can have a devastating effect on uniform crops as previously reference to the corn failures in the 1970's in the US. The trend of reliance on a monocultural -uniform variety exposes the crop to increased failure potential. This monocultural method can also impact the soil and in particular the amount of soil organisms and soil nutrients. Beneficial insects and fungi can also suffer as a result of heavy pesticide inputs and uniformity making crops more prone to pest problems. In addition many insects and fungi commonly seen as enemies of food production are actually valuable through pollination-biomass contributions natural nutrient production and cycling and as natural enemies to insects and pests associated with crop disease. The continual expansion of modern agricultural control systems has eroded the range of beneficial insects and fungi and in doing so, have impacted negatively food production. Dependence on agrochemicals and the general non selective manner in which the chemical kills all that is exposed to the chemical, does equal harm to the natural enemies and beneficial insects as well as the targeted species/pest. Pesticides-especially when they are overused- can have a dramatic changing effect on the host environment for the beneficial insects/fungi and can lead to a resurgence or outbreak of new and more resistant pest species.

The World Resource Institute provides a short account relative to sustainable agriculture and some of the conflicts created through agrobiodiversity loss.  The audience is directed to pay specific attention called to the assorted tables which are noted on page 2, 3 and 4. Information relative to the reduction of the number of varieties of a crop, such as Rice in Sri Lanka, from 2,000 varities in 1959 to less than 100 varieties today is eye opening. Additional information notes the reduction of diversity in Fruits and Vegetables from 1903 to 1983, reflecting per cent losses well within the 90 percentile. Of particular interest is the table depicting past crop failures due to genetic uniformity
http://www.wri.org/wri/sustag/lba-home.html

BIOLOGICAL CONTROL

Plant Diseases

Plants can and do get sick and unhealthy. If the cause of the plant disease is an infectious agent, this is called a pathogen. Certain fungi, bacteria and viruses can infect plants and disrupt their normal cycles. The affects can be noticed in various ways such as blemishes; lesions; color loss; slow growth and other matters such as loss of leaves. There needs to be a concern about plant diseases because plants serve many beneficial functions - of which the most important is the providing of the primary food source for all humans and animals in the world. Given the importance of plants as a food source, methods must be employed to keep plant diseases and pests in check, otherwise these disease and pests could destroy most of the world's food supply. As previously discussed, plant diseases have impacted humankind throughout history.

The control of plant disease depends on the specific nature and characteristics of whatever is causing the disease. Plant diseases are typically controlled by either physical; chemical; or biological methods.

Physical or cultural control involves the physical management of the plant environment to remove the disease carrying pathogen or make the environment unfavorable for disease development through practices such as soil tillage; crop rotation ; plant sanitation; heat; barriers. Oftentimes these methods are labor intensive.

Chemical control involves the use of chemical pesticides to eradicate or reduce the population of the disease causing species or to afford a protective barrier against the disease. While these may be effective for some applications, the chemicals may not be species specific and may cause harm to beneficial organisms as well as causing environmental concerns.

Biological control is very specialized and uses one or more organisms to control the disease. The use of a biological organism excludes man. Biological control has been used in agriculture to control insects, weeds, and plant diseases. A beneficial organism used to control a pathogen is called a Biological Control Agent or BCA. Another term applied to biological control agents is antagonists, as they antagonize or interfere with the disease-carrying organism. The antagonist is generally a naturally occurring soil microorganism that has some traits or characteristics that help interfere with the growth and spread of the disease organism.

Advantages associated with the use of biological controls allow for the reduction of the use of chemicals in the food production process. Additionally, the use of biological controls can reduce or prevent the genetic development of tolerance within targeted species commonly associated with continual chemical use and the need to continually develop genetic variety. A common disadvantage associated with biological controls is that it does take specialized knowledge before it can be implemented . Close management of all control agents is required to insure that once the disease or pest host is controlled, the control agent does not seek out non targeted species and cause significant economic loss in food production.

The USDA article on Plant Disease and Biocontrol notes in more specific detail the relationships between disease and control.  Highlighted in this article is the importance of plant diseases and numerous short answer sections to general type questions relative to Biocontrol.
http://www.barc.usda.gov/psi/bpdlfaq/faq.html#Q1

SOILS

Before proceeding further into the more specific benefits of natural control methods, it is important to pause and reemphasize the importance of understanding the ecosystem is rooted in soil-no pun intended. Soil provides the physical foundation for virtually all human activities--most of all agriculture. Soil biodiversity and the whole ecosystem process related to this diversity is the central hub for an interactive and healthy -environment. The following diagrams, note the interactive webs within the soil . Click here to find additional in-depth information in regards to the biodiversity and ecosystem functioning in soil.  NOTE: Go to Table 1 on Page 21 and Table 2 on Pages 22 and 23.. Of interest in the above noted tables is the reference to the types of soil dwelling species and the functions of the major groups of soil organisms.
http://www.nrel.colostate.edu/soil/scope/soil.html
 

PEST MANAGEMENT PRACTICES AND CHEMICAL USE

In regressing to refresh the role of an active and diverse soil environment, it is equally important to remind the reader why we are writing about the use of natural methods to control diseases and pests and not depend so heavily on chemical use for pest management. The below noted linkage address will present the results of a survey taken in 1995 by the University of Florida-IFAS group. The survey was conducted to document pest management practices and chemical use in Florida's Ornamental Plant Nursery Industry. This industry was ranked in 1993 as the second largets of its kind in the United States with over 5,000 farms and annual revenues exceeding $1 billion.

This is a must look up informational linkage, if only to take the reader to the appendix of tables which note page after page the insecticides, miticides herbicides fungicides and plant growth regulators used just in the Florida nursery environment. Of particular relevance is the small percent of use firms incorporating Biological control agents in the Florida Ornamental Nurseries.  http://edis.ifas.ufl.edu/body-AA242.html

INSECT BIOLOGICAL CONTROL

Insects are the dominant life form on earth as millions may exist in a single acre of land. Estimates place the number of identified insects at one million while some research notes there may be as many as ten million remaining to be identified. Of all species on earth, insects are the primary food consumers. They play a critical link in decomposition and food supply. With the possible exception of the ocean environment, insects can be found throughout the earth.

As shown insects typically pass through four distinct life stages-egg; larva; pupa and adult.

Oftentimes in assessing the influence of insects to their environment, it is better to consider insects as populations rather than as an individual species member. Populations have attributes such as density-age distribution birth and death rates . These are all factors into understanding biological control management.

Biological control is a part of integrated pest management which is defined as the reduction of a pest population by natural enemies and usually involves human interaction.

CONSERVATION - BIOLOGICAL CONTROL

Special note is made of the relationship of conservation as a form of biological control. While this lecture will conclude with an in depth look at natural control methods, the simple practice of conserving what exists naturally, and understanding the benefits and not reaching for the spray or the shoe to snuff out all insects will go a long way in driving home the importance of conservation as a major component of biological control.

CLASSICAL BIOLOGICAL CONTROL -- NATURAL ENEMIES

PREDATORS / PARASITOIDS / PATHOGENS / WEED FEEDERS

NOTE:  THIS FINAL SECTION WILL INVOLVE AN IN DEPTH LOOK AT FOUR GROUPS OF NATURALLY OCCURRING BIOLOGICAL CONTROLS; PLEASE LINK TO THE NOTED CORNELL UNIVERSITY WEBSITE FOR PHOTOGRAPHS AND INFORMATION RELATIVE TO THE ABOVE REFERENCED INDIVIDUAL SPECIES OF NATURAL ENEMIES.  IN REFERENCE TO THIS SITE, AND THE LECTURE, THE AUDIENCE IS DIRECTED TO THE Table of Contents AND SPECIFICALLY TO THE SECTION NATURAL ENEMIES-Predators;Parasitoids-Pathogens-Weed Eaters. THESE SECTIONS WILL PROVIDE DETAILED INFORMATION AND PHOTOGRAPHS OF REPRESENTATIVE NATURAL ENEMIES. THIS COMPLETE DOCUMENT IS RECOMMENDED AS A MUST READ!!!
http://www.nysaes.cornell.edu/ent/biocontrol

 The advent of synthetic insecticides in the 1950's came with much fanfare as the easy control of pests which impacted food production appeared to be manageable and the efforts to increase food production were just over the horizon. Unfortunately, in the years that followed, the fanfare and production was tempered by environmental concerns and genetic tolerances of targeted pests and insects. The secondary impacts to many beneficial environmental attributes took their toll and the control of pests and diseases actually diminished. This situation created increased chemical useage and stronger applications- in concert with genetic uniformity and the growing weakness of food plants to control pests and diseases.

The primary protection to food crops is still heavily dependent on chemical application. This practice still carries with it the historic concerns generated over the years relative to environmental impacts and presents a significant expense to the agricultural community .

The use of insect pests to manage other pests which are harmful to the food crops is known as biological control and it is known that all insect pests have natural enemies. The maintaining-conserving and continual development of an environment rooted in biodiversity is critical to the sustained success of the agricultural community. The increased use of biological control /natural enemies in balance and complement to the use of more traditional methods of control will go a long way to guard against the repeating of past agricultural /food production failures.

Weeden, Sheldon, and Hoffmann, Editors. Biological Control: A guide to Natural Enemies in North America. Cornell University. 1998.  This is an OUTSTANDING DOCUMENT- as referred to in the - NATURAL ENEMIES section of the lecture and representing a source of immense subject knowledge.

Brussaard, Behan-Pelletier, Bignell, et. Al. Biodiversity and Ecosystem functioning in Soil. 1997.  This is a collaboration of many researchers into the significance of soil -biodiversity and the ecosystem.  This is yhr reference in the lecture under the SOILS section.

Hodges, Aerts, and Neal. Pest management Practices and Chemical Use in Florida's Ornamental Plant Nursery Industry. University of Florida-IFAS. 1995.  Excellent survey document of a dynamic Florida Industry. Significant value in associated Tables which highlight types of targeted species and control agents. This is noted in the lecture under the section of PEST MANGEMENT PRACTICES.

Larkin, R.P. USDA Compiled Report: Plant Disease and Biocontrol FAQ. New England Plant, Soil and Water Laboratory, Orona Me.  General question and answer look at some basic issues relative to plant diseases. Lecture reference can be found under section PLANT DISEASE.

The following references refer to assorted aricles derived from the publications of the World Resource Institute;

Sustainable Agriculture. Agrobiodiversity Loss: Conflicts and Effects. 1997  Article notes erosion of crop and livestock and vulnerability to pests and insects. Some excellent tables which are referenced in lecture section AGROBIODIVERSITY LOSS

Sustainable Agriculture. Agrobiodiversity as a Basis for Production and Survival.1997.  Article presents good definition of agrobiodiversity and associated benefits. Refer to lecture section AGROBIODIVERSITY.

Biodiversity. Agriculture and Genetic Diversity. 1989  Article highlights values of genetic diversity for agriculture. Refer to lecture sectin AGRICULTURE AND GENETIC DIVERSITY

Biodiversity. Genetic Diversity.1991.  Article notes problems with genetic uniformity. Refer to lecture section AGRICULTURE AND GENETIC DIVERSITY