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This week's Book of the Week feature is The Non-Toxic Farming Handbook by Philip Wheeler and Ronald Ward.
From Chapter 5: Insect Damage
Insects and insect damage have been called the “farmer’s curse.” It is true that each year millions of tons of produce, grains, and fruits are destroyed or damaged by insects. Insects account for a 13-16 percent loss from $244 billion in crops annually in the United States. Insect numbers count in the billions and their collective weight by far surpasses the collective weight of mammals. Of more than a million zoological life forms identified and categorized by scientists, more than 800,000 consist of insects. It is believed that as many as 10 million insects remain as yet to be identified. Aside from our annoyance with these pesty critters and their attacks upon crops, pets, and livestock, what is their purpose?
Insects actually benefit man. Estimates of the value of insect pollination from honey bees and wild bees alone amount to approximately $30 billion annually in the United States. Insects pollinate fruits, berries, grapes, and field crops including peas, onions, carrots, clover, alfalfa, and flowers. In addition, insects provide millions of dollars annually in the form of such items as honey, shellac, and silk.
Many insects are actually beneficial to man because they devour insects harmful to our crops. Ladybugs, for example, will eat aphids. These predators play a useful role in maintaining balance within the insect kingdom.
Less than 1 percent of the insect species are considered harmful. About 1,000 species are considered serious crop pests, another 30,000 species are described as minor crop pests. Their control cost is only slightly less than the value of the crops they would have destroyed if left alone. In 1995, worldwide expenditures for pesticides hit $37.7 billion; U.S. expenditures came in at $11.3 billion.
Insecticides are the modern mode of insect control. Insecticides come in either dry or liquid form and are either dusted or sprayed. They are used to prevent insect damage as well as to kill the insects after they have arrived. Insecticides come in several types. Some are stomach poisons which react within the insect after being consumed. Others kill on contact. Others, called systemics, are absorbed by the plant or animal and affect the insect after it bites the treated host.
Now that public awareness has increased and public opinion has caused the EPA to review pesticides, it is expected that many will not be allowed to remain on the market. This scenario has prompted Steve Brown, Auburn University Extension Service, to list several alternatives for farmers to consider. These can be considered as part of an IPM or Integrated Pest Management program.
- Select insect-resistant varieties.
- Calculate closely such variables as planting dates and row spacing.
- Take advantage of crop rotation benefits.
- Utilize pheromones (insect sex attractants) to capture or disrupt insects or introduce predator insects.
- Utilize the biological pesticides which are available.
- Consider trap crops in certain instances.
- Utilize plastic mulch.
- Consider soil solarization, using clear plastic.
- Utilize machinery which sucks insects off plants.
Although these suggestions represent creative solutions to a growing reality, they miss the mark in that they don’t address the cause for the insect infestation in the first place. Once the variables influencing insect attack are understood, steps can be taken to remedy these causes. Addressing the cause will produce more lasting results.
Dr. Philip Callahan, renowned authority on the corn earworm and author of The Soul of the Ghost Moth and numerous other books, has studied insects extensively in his role as USDA researcher. His research indicates that insects communicate via infrared signals which are received and sent by the insect antennae which occur over much of their bodies. Each insect is apparently sensitive to certain plant signals and ignores others. Most damaging insects are selective in what they attack. Thus, the alfalfa weevil would not infest elm trees.
Infrared signals are emitted naturally by all living plant or animal bodies as well as from the gaseous emissions of all plant and animal life. Signal strength and configuration are affected by a variety of factors including nutrient balance and stress factors. Insects detect these signals with their antennae.
Upon close examination, it is evident that each species of insect has an antenna shape unique to its species. According to Dr. Callahan, the shape of the antenna determines the signal range received by the insect. Thus, the shape of weevil antenna allows it to be attracted to alfalfa frequencies.
When plants are grown in a soil with balanced nutrients and the plant itself utilizes those nutrients in a balanced manner, its own system will maximize its genetic potential in terms of yield and health (or resistance to stress). However, when the soil is out of balance, when normal growth stresses, e.g., drought, excess water, heat or cold, wind or hail occur, the plant may require other nutrients to counteract the stresses at hand. The extent those nutrients are missing is the extent the plant will suffer and, eventually, deviate from its genetic potential.
The infrared signals given off by the plant will modify depending upon the health of the plant. As the plant moves further from ideal health, the signals become more pronounced in a way that attracts insects. This can be shown by taking refractometer readings and observing that the brix reading measured as percent sucrose on attacked plants is lower than plants not being attacked. The brix reading is a good indication of the efficiency of the plants’ output of carbohydrates which is the result of photosynthesis.
A properly balanced soil will have sufficient quantities of organically active carbon — humus — which helps hold nitrogen in the ammoniacal form. In soils lacking this active carbon content, the soil will give up this ammoniacal nitrogen to bacterial conversion into nitrates or directly to the atmosphere in gaseous form. During the process of ammoniacal nitrogen leaving the soil, it passes by the plant and can act as an amplifier of the infrared signal coming from the plant. Whereas the plant may have been initially broadcasting the signal, “I’m not balanced nutritionally,” the signal now reads, “Come and feed on me!”
Dr. Reams taught that most insects do not attack healthy plants. His whole approach to plant fertility and insect control capitalized on supplying the soil balanced forms of plant food which, in turn, maximized plant health. Insects look for signals coming from unhealthy plants and seldom attack healthy ones. Insects willingly eat weeds and will return to that practice in fields with healthy crops and soils and unhealthy (low brix) weeds. The attacking of weeds by insects is one of the signs to look for in observing your progress toward sustainable agriculture.
Failing Plant Health
The research conducted by Dr. Callahan and Dr. Reams has immense implications. If insects attack unhealthy plants and ignore healthy plants, they are telling a sad story about the fertility approaches as currently practiced. By attacking unhealthy plants, insects are actually benefiting humanity by pointing out which plants are unhealthy, low in mineral content, and not fit for human or animal use. The astute farmer views insects, as he views weeds, as messengers of soil or crop conditions, not the cause of them.
Many farmers are beginning to work with the IPM (Integrated Pest Management) approach to insect control. President Clinton once announced his intention to have a large percentage of U.S.A. crops grown under IPM by the year 2000 in an effort to reduce the amount of toxic chemicals used.
This concept consists of setting out insect traps baited with the sex scent (pheromones) of insects and then observing insect populations. If the insects are present, but in a number below that which would cause significant crop damage, no spraying should occur. If the population indicates significant crop damage will occur, steps are taken to control their numbers, hopefully with non-toxic materials. Other aspects of IPM include the release of mating disruption pheromones or predator insects to devour the harmful ones present on the crop.
Increasingly, farmers are turning to non-synthetic pesticide options such as botanical, microbial or predator approaches. These consist of using plant extracts such as nicotine from tobacco leaves, pyrethrum from flowers, rotenone from roots as natural insecticides; using plant extracts such as garlic juice and capsicum from peppers as repellents; microbial vectors that destroy harmful microbes or larger organisms; and predatory insects to control insect pressures.
Ladybugs and lacewings are traditionally welcomed in the field as a predator of moths and other destructive insects. Additionally, their presence usually indicates a relatively low level of toxic contamination in the field, since they are also killed off by toxic sprays. Ladybugs usually are considered an indication that the field environment can sustain beneficial insect life.
It is important to consider using a foliar nutrient or feed with any type of insecticide whether synthetic or natural. Any plant under attack by insects is mobilizing its defenses. This requires nutrient and energy utilization. Wouldn’t it be wise to give some “chicken soup” to your crop along with anti-insect treatment to aid in its recovery?
An interesting natural product for insect control is diatomaceous earth. D.E., as it is commonly called, consists of the shells of tiny fresh or sea water diatoms which have been deposited on old lake beds over millions of years. They are mined and milled into powders for feed or for use as a filtering agent in swimming pools. The swimming pool product cannot be used in feed as it will damage the animal consuming it. Since it will absorb many times its weight in water, D.E. is considered to be an anti-caking ingredient for feed. It is often fed by alternative ag farmers, not because of its anti-caking properties, but because of claims it will control parasites in animals. Although it feels like talcum powder to the touch, you would see extremely sharp edges under a microscope. Supposedly, when the substance comes into contact with an insect it will scratch the insect’s cuticle. Death often follows from dehydration. How it works internally is not fully understood. Some think it de-energizes the parasite in the stomach.
Although only a few brands of D.E. on the market have gone through the EPA registration requirement to be considered a pesticide, other brands could work the same. Recent university research has shown that the vegetable oils used with pesticides may also give excellent insect control when used alone. However, the EPA has yet to “catch up” with this information and give its full “blessing.”
Could it be that insects and weeds are symptoms of a problem rather than problems themselves? Could it be that fertility approaches exist which can correct these basic problems exemplified by insect and weed pressures? Are these pressures related to fertility practices? If this is the case, how does the farmer determine the correct fertility program to use?
ABOUT THE AUTHORS:
Philip A. Wheeler has worked as the technical advisor and consulting agronomist for Crop Services International in Grand Rapids, Michigan. CSI is a soil testing lab and consulting service operated by Phil and his wife Louisa. He is a national lecturer on biological and sustainable agriculture and its relation to nutrition and health. An amateur dowser, graphologist and metaphysician, Phil also enjoys composting and gardening. He is a member of American Mensa.
Ronald B. Ward grew up in suburban Grand Rapids, Michigan. At the age of 9 his parents bought a 50-acre farm 25 miles away from their city home. He obtained a B.S. in park management from Michigan State University; a master’s of divinity from Asbury Theological Seminary; and a master’s in community counseling from the University of Kentucky. After working for and eventually directing the Lexington Central Kentucky Re-ED Program for emotionally disturbed children, Ron returned to his country roots where he was introduced to alternative health and the Reams method of testing urine and saliva.
Titles of Similar Interest:
- Eco-Farm, by Charles Walters
- The Farm as Ecosystem, by Jerry Brunetti
- Hands-On Agronomy, by Neal Kinsey & Charles Walters