A Six-Legged Solution to Pollution

The U.S. not-for-profit Environmental Working Group recently published a list of 43 fruits and vegetables according to the amount of pesticide(s) each would bring to your table. The ranking was based on the results of nearly 43,000 tests for pesticides done by the U.S. Department of Agriculture and the U.S. Food and Drug Administration between 2000 and 2004. The group makes available both a detailed description of the criteria they used to develop the ranking, and the full data set for the resultant list.
They started their list of studied fruits and vegetable at the number one, for the food item you want to avoid the most. Grabbing that #1 was the peach, which had the highest likelihood of multiple pesticides on a single sample. 86.6% of the sampled peaches had two or more pesticide residues.
Waltzing in at the number 41, out of 45, was the mango. Fewer than 10% of the mangoes sampled had detectable pesticides on them and fewer than one per cent had more than one pesticide residue. The results, of course, are based on U.S. grown produce, but they still have a great deal of relevance to Canadians since so much of the produce sold in our stores is imported from the States.
If this news concerns you, one way you can lower your exposure to pesticides is to buy organic. A valid concern, however, for those farmers seeking to produce crops that can be certified organic is how to control pests that endanger their crops and threaten their profit margin without resorting to pesticides.
The July issue of "The Economist" presents an article titled "Ant and Tech". It highlights a pollution-free solution to the problem for mango farmers that has been producing great results in Africa. There, fruit flies attack and destroy approximately 40% of the continent's crop. The flies are so common a problem in African mangoes that America has totally banned the import of the fruit, in an attempt to protect its own groves.
The use of pesticides, which might help with the problem can present the African farmer with his own sword of Damocles, since they cost more than the farmer may be able to spend, are difficult to spray effectively on tall-standing trees, and are generally a case of closing the barn door after the livestock has all wandered off, since the farmer must first spot an infestation before he sprays for it.
Agricultural scientists looked at using parasitic wasps to control the pesky flies but the wasps kill only about one fly in 20, which means far too many survive. About the only recourse available to the beleaguered farmers was the early harvest of their crops, beating the flies to the punch. This reduced the crop value.

A way to increase the value of the harvest by as much as two-thirds has crawled up the mango tree trunks, however, and presented itself in the form of weaver ants. A study by Paul van Mele and his colleagues in the Consultative Group on International Agricultural Research on these busy little insects and their effects on mango crops has been published in the latest issue of the Journal of Economic Entomology.
Van Mele surveyed several orchards in Benin and found less than one fruit fly pupa in each batch of 30 mangoes from trees where weaver ants had taken up residence, while there was an average of 77 pupae in batches from trees without the little six-footed fruit fly foes. The weaver ants are most efficient at mounting a posse to track down and ingest fruit flies and a host of other mango harming pests. They can deliver a painful bite to humans but an easy way around that problem at harvest time is simply to do the work with poles rather than shinnying up the trunks.
Weaver ants have been used as six-legged pest control in Asia for many long years and Australia, too, has begun using the mighty, miniature warriors. What's holding back North America?
Van Mele set out to teach a group of farmers in Burkina Faso how to make use of the weaver ants, needing just one day for the whole process. All he had to do was to show them how to run a string from a weaver ant nest to the trees needing their protection. Instant, inexpensive, and innocuous, the ants allow the farmers to market their mangoes as organic to the European market, and greatly increase their income thereby.
We need to think about what pesticides are capable of killing, along with the fruit flies. For a real eye-opener, you might want to read "The Body Burden", a report on an investigation looking at industrial chemicals, pollutants, and pesticides found in human umbilical cord blood. Popular wisdom used to teach that the placenta shielded the cord blood and the baby from most chemicals and pollutants, but that head-in-the-sand idea has been blasted out of the waters of our complacency now.
Maybe we don't need to use poisons strong enough to kill on the foods we put into our mouths and the mouths of our children. Maybe we just need to have a little more patience and look a little more to nature.