Why do we mention this in Midwest Biological Control News? Because farmers are in the process of inventing new technologies today, including new uses for natural enemies in biological control or IPM programs. Capitalizing on the natural inquisitiveness of farmers offers a tremendous potential for biological controlone that can be better utilized by Extension and University staff responsible for developing biological control efforts in their area.
What Farmers Know. The ultimate "integrator" of the information farmers receive to increase production, stabilize yields, use pesticides, etc. is the farmer him/herself. It is the farmer that "lives the problem," gains the benefits, and suffers the consequences. The farmer is observant of the nuances of his/her production system and eager to try new things. A researcher with his/her technical training and jargon may think a farmer is uninformed if he/she calls an insect's pronotum the "bug's neck"but both are referring to the same region of the beast. Likewise, an Extension specialist may wonder just what a farmer is thinking when he/she plants marigolds to increase tomato yields ...until they find out that the roots of marigolds offer protection to the tomato plant from root-infesting nematodes. On the one hand, the differences in terminology and training can separate farmers from researchers and extension workers, but ideally the differences in experiences and training can be used to catalyze a new understanding. An example may be illustrative. In a project in Honduras, my graduate student, Luis Canas, is determining whether sugar solutions applied to corn attracts natural enemies that control the fall armyworm. The idea for using sugar solution can be found in a number of scientific journals and has been tried in the U.S. in alfalfa and some vegetable systems with some success. However, the idea for using sugar solutions to attract natural enemies in Honduran corn came not from a scientific journal, but from a poor, illiterate farmer, who when given sufficient information "put 2 & 2 together" and invented a new technology. What she did was take what she knewin this case that ants like sugarand added it to something she was recently taughtthat ants are predators. It is important to note that she wasn't taught to use sugar to attract ants to control pests, only that ants are predators. And how did we know to teach her that ants are predators? Because we were fortunate that an anthropologist (Dr. Jeff Bentley), understood what farmers knew, and what they didn't know. By talking with farmers, Dr. Bentley realized that, among other things, they only thought of ants as pests, whereas agricultural scientists knew that ants were important predators. By teaching farmers that ants were predators (indeed that there are even things like insect predators), he felt confident that the inquisitiveness of farmers would "come up with something." In one course sat our farmer"Hmmm, ants are predatorsthey like sugar, because I see them in my sugar bowlperhaps if I put the sugar on my corn the ants will come and eat the pests". Voila! She invents a technology, exactly like the one we here at the University discuss in our professional journals! The point of this story is that when we invigorate the experimental engine of farmers, they will invent all sorts of things to try to solve their problems. Farmers experiment with the familiar to gain insight on what they don't know. How many new biological control uses would we have if farmers knew more about biological control or natural enemy biology? Once farmers know that pests have natural enemies that can be used in control, we will see more attempts at biological control than if biological control remains the sole "property" of University or Government scientists.
Of course, some inventions will work and some won't. Without failure we can not reap the benefits of success. It is also important to point out that the process of farmer innovation is similar to the process of experimentation followed by researchers. There may be differences in the background appreciation of the problem, scientific validity and statistical rigor, but that does not preclude farmer innovation from being a powerful mechanism in agriculture development (witness the plow!). Coupling the experimental protocols of the scientific method to the farmer's deep appreciation of their system would seem to be a powerful way to generate new agricultural practices, including biological controls.
Experimenting with Biological Control. Readers of this newsletter know that there are three ways of doing biological control: classical, in which exotic natural enemies are introduced to permanently control introduced (sometimes native) pests; conservation, in which the environment of the natural enemy is modified to be more conducive to the natural enemy, and augmentation, which uses periodic releases of natural enemies to effect control. Since the classical method involves the importation of new, exotic natural enemies, farmers are unlikely to be (indeed should not be!) involved in importing natural enemies, although they may be of assistance in various ways, such as allowing releases on their property. It is more in the areas of conservation and augmentation that farmers can be innovators of new technologies.
Conservation. Preserving the environments of natural enemies can do much to increase their effectiveness. Perhaps the number one way to conserve natural enemies would be to reduce the rate or frequencies of pesticide applications. Thus, farmer experimentation with "organic" pesticides, so-called biorational products (e.g. Bacillus thuringiensis), or the timing and rates of applications should be encouraged to increase biological control. Comparisons to control plots, non-treated areas, or "averages" for the area can give farmers an appreciation of the effectiveness of their conservation action. Encouraging farmer participation in pesticide trials and experiments on other conservation approaches (e.g., cover crops) should be the norm. By listening to farmers' conservation ideas (the same group of Honduran farmers planted flowers to attract predaceous wasps), researchers can use scientific methods to sieve the successful ones from those that do not work. Importantly, by including farmers in experimental designs and research agendas, we will increase the number and diversity of conservation approaches, and increase the likelihood of adoption of appropriate conservation methods.
Augmentation. Farmers have over 100 species of natural enemies they can purchase from nearly 50 companies nationwide. Some species, such as Encarsia formosa are highly effective (against greenhouse whiteflies), whereas others are of dubious use (e.g., ladybird beetles) or are outright worthless (e.g. praying mantids). Extension recommendations for using commercially-available natural enemies are relatively rare, but are increasing in number in several systems (e.g., home gardens, greenhouse ornamentals, fruit trees). We may see the greatest increase in closer Extension-farmer efforts in the area of augmentative biological control. It has happened a number of times already that the farmers were successfully using natural enemies without the advice (or knowledge) of Extension personnel. In using commercially available natural enemies, the farmer should purchase them from a source they have had experience with or is known to other farmers or Extension specialists. When ordering natural enemies, order only those that you need and only when you need them. Check to be sure they arrive alive, checking for activity or by taking a small sample of the order and holding it for emergence (a small hand lens will be very helpful here). Many companies include release informationfollow label instructions. Release early in the morning or at dusk and observe the natural enemies moving about following release. Evaluate success against a control where the natural enemies have not been released (or make evaluations based on your own experience). Contact your local Extension service to find out more about the natural enemies and their use in your particular system. Remember that many Extension people have had little or no experience working with natural enemies (although this is changing), so invite them to observe your experiment! Start small and go from there.
Conclusions. Where do we go from here? Using biological controls are like many agricultural technologies. Farmer innovation has had and will continue to have a major influence on the development of successful programs. Partnerships between farmers, Extension personnel (both at the state and county levels) and researchers will increase the rate of success and identify new areas of effort that neither group alone would have discovered. Trusting farmers to experiment means that we do not need to give them recipes, but knowledge. Training sessions on case histories in biological control, on-farm experiments, and natural enemy biology will catalyze new approaches. Our Honduran farmer is but one example of the dynamic inventiveness of farmers, and her Brazilian counterparts represent the potential for harnessing this process. Hopefully in the future we will have Midwestern examples to brag about!
- Bob O'Neil, Purdue University
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