Natural Pest Control: Minimizing Pests the Natural Way

These little guys can take over if their numbers get out of control. (from left to right, mosquito, slug, parasitic wasp)

Modern pesticides and fertilizers are expensive and are toxic to humans, animals, our environment, and yet they are used on a majority of cropland.  In 2001 herbicides (a type of pesticide) were applied to 98% of corn acreage and 96% of soybean acreage.[5]  Residues are common in vegetables, fruit, grains and meat. [6]  In 2002 the USDA found that 47% of the produce, 16% of the grains, and 15% of the meat they tested had detectable pesticide residues.  Pesticide residue was also found on 64% of imported fruits and vegetables, with the highest concentration of residues on strawberries, mangos, peppers, and bananas.  The most commonly found pesticide was methamidophos, which poses a serious health threat to humans.[7]  Most of the residues found in meat were from persistent chemicals, like DDT, that have been banned for years yet remain in the environment without changing for long periods of time.[8][9]  Some pesticides can leach through soil and enter the groundwater, contaminating the drinking water for millions of households in rural areas that depend on drinking water for their primary water source. [10]

While the EPA regulates tolerance levels for pesticides in the U.S., studies have shown that many of the tolerance levels are dangerously high because of the unreasonable assumptions they have used to set them. [11]  Scientists from the Environmental Protection Agency say there is "sufficient evidence" to conclude that the most widely used pesticide in the U.S., atrazine, is an endocrine disrupting chemical and causes sexual abnormality in frogs.”[12]

Unfortunately chemical pesticides are indiscriminate in wiping out life. Pesticide drift is responsible for injuring birds, fish, sensitive plants and other wildlife. If poorly timed, pesticides can kill bees and other pollinators in the area and other beneficial parasites and predators that help naturally control pests.[13]

These days it seems that the only thing pesticides don’t harm are the very things they were designed to eradicate.  Resistance to pesticides is becoming increasingly problematic, for example, there were no knows weeds with herbicide resistance in 1970, now there are over 273 known herbicide resistant weeds.  There are approximately 1000 species of agricultural pests that are resistant to at least one pesticide and some pests that are resistant to all pesticides that are legal for use.  This is costing the agriculture industry billions of dollars every year in increased pesticide costs and decreased yields.[14]

Resistance has developed because of high rates of pesticide use and the increasingly specific nature of modern pesticides, which allows for faster development of resistance.[15]

Employing natural farming techniques doesn’t mean a return to watching pests destroy crops.  The first step is to have a better understanding of the pests themselves, their life cycles, and what deters them.  This enables implementation of clever solutions and preventative measures using a system of integrated pest management to reduce reliance on pesticides.  The main components of integrated pest management include:

• Setting an Acceptable Level of Pest Population: Eradication is impossible and will lead to more problems, it is therefore important to focus on reduction instead of elimination.
• Preventative Practices: Selecting crops that are best suited for growing conditions, and quarantining or removing infected plants to prevent spreading. Diversity of height, color and fragrance can deter those pests that are seeking the monoculture. 
• Monitoring: Successful pest control requires accurate identification first and then close observation and recordkeeping.  Since insects are cold blooded, their development is dependent on temperature so it is important to monitor the degree-days to determine the life cycles and when outbreaks will occur so we can target the right time to apply mechanical, biological and chemical controls.
• Mechanical Controls: This is the first line of defense when a population has reached unacceptable levels and includes hand picking, insect barriers, traps, pheromone lures etc.
• Biological Controls: Reduction of pest populations by natural enemies.  These can include: predators, parasitoids and pathogens for insects; antagonists for plant pathogens; herbivores and plant pathogens for weeds. This approach provides control with little environmental impact, unless the biological control is improperly selected which may result in unwanted effects on native species, which may affect the regions natural biological diversity. 
• Chemical Controls: Many natural pesticides can be made at home from plants.

Some select biological and chemical controls that we may employ at the center include:

• Birds and Bats: Both eat millions of bugs a day.
• Insects:
  • Ladybugs: One ladybug will eat up to 100 aphids a day.[16]  To draw more ladybugs we will plant butterfly weed, coriander, marigold, and tansy.
  • Dragonflies: Natural predator of mosquitos.
  • Lacewing: Some species will eat 100-200 pests a week, including aphids, thrips, spider mites, and other soft body insects in their immature states[17].  Attracted to yarrow, dill, cosmos, fennel.
  • Minute Pirate Bugs: Attracted to caraway, alfalfa, spearmint, and goldenrod.
  • Earwigs, parasitic wasps, assassin bugs, Green, Syrphid Flies, Big-eyed Bugs, and Praying Mantis, all eat soft body insects.

• Mycological Mixtures: These are a potent nematicide and parasiticide.
• Natural Insecticides: Citronella, eucalyptus, neem, and pyrethrum (from the Dalmation Chrysanthemum).

There are myriad natural pesticides in use throughout the world today, using ingredients as common as soap or as exotic as nicotine.  Natural pest control methods are simple enough that anyone can and should practice them.  We will test the effectiveness of biological and chemical controls and the center and share what we learn with our neighbors and our community, and learn from experts in the field so that we may cultivate a world together where we will no longer need to use toxic chemical pesticides.