Technorati Tags: ,,,

 

Lest you think this is something thought up just to annoy you, rest assured, your great-great-great-great-great-etc. grandparents had just as many (if not more) disgusting and obnoxious household pests as you do – both in body and in agriculture.

For example, guinea worms (three-foot-long worms that mature from larvae inside your body and then burrow out of you via acidic secretions) have been found in ancient Egyptian mummies, caterpillars were mucking up Chinese citrus groves by 1200 BCE, and the 8th century BCE poet Homer wrote just one of many, many literary accounts of locust swarms attacking plants and people.

Natural Defenders

It’s highly likely that some of the earliest means for fighting common pests were natural ones. For instance, those Chinese citrus farmers didn’t just sit around and let the caterpillars take over. Instead, they built an intricate network of ropes and bamboo sticks that connected tree-to-tree and high branch-to-low. Then they released a particular species of insectivore ant that quickly went to work devouring every caterpillar (and, as an added bonus, every wood-boring beetle) in sight. The scaffolding provided by the humans helped the ants move efficiently through the orchard and made it easier for them to clear every tree of invaders. Strangely enough, biological controls similar to this ancient one are still being used today. In fact, it’s actually a little easier to “outsource” the predator’s work now that we have access to a planet’s worth of animals and can import the best ones from several continents away. In the 19th century, for example, California citrus growers imported a species of ladybug from Australia that turned out to be extremely well-adapted to killing off the cottony cushion scale, an insect that litters citrus trees with thousands of pillowy egg sacks. The African cassava mealybug, responsible for destroying much of that continent’s nutritionally important cassava crop, was brought under control by a South American wasp in the 1980s. And, in a slightly different scenario, a moth introduced to Australia in the 1880s was able to completely wipe out the prickly pear, a plant that had caused ranchers no end of trouble as it choked out edible species from the land.

Besides exploiting predatory scenarios, humans have also been selectively breeding hardier pest-resistant plant species and sub-species for thousands of years. In fact, archaeologists believe that this has been happening, albeit rather unconsciously, as early as 7000 BCE. The first real scientific research on the subject was done in the 1870s by entomologist C.V. Riley. By grafting tough, resilient American grapevines onto their more delicate European counterparts (the grape equivalent of interbreeding), Riley was able to halt a massive outbreak of the grape-destroying phylloxera aphid. Before Riley and his American vines saved the day, phylloxera had eaten up nearly a third of the wine grapes in all of France. Of course, Riley’s efforts didn’t go unnoticed. For saving he wine industry and making the world safe for future generations of liquor snobs, riley was awarded the Gold Cross of the French Legion of Honor, the equivalent of the American Presidential Medal of Freedom.

Chemical Repellants

Don’t be fooled. Just because our ancestors were fighting pests by natural means, doesn’t mean that they were opposed to tossing toxic chemicals at the buggies. In fact, history shows that humans have been drenching their soil in pesticides for almost as long as we’ve been farming. Ancient Mesopotamians apparently dusted their fields with powdered sulfur. Other ancient societies fought the good fight with things like arsenic, lemon oil, wormwood, the aptly named fleasbane, and salt. And the ancient Egyptians even used a mixture of natron, a strong salt used in the mummification process, and water to rid their homes of fleas and lice. Believe it or not, these early methods were perfected and used for centuries. In the 1st century CE, Romans were still fighting insects by burning sulfur and letting its smoke “gas” their crops. Even as late as the 17th century, the basic ingredients of chemical remedies remained largely unchanged, with household ants killed off by a mixture of honey and arsenic. The truth is, even today, sulfur remains an important element in chemical control. In the 1840s, sulfur dusting and a spray made of sulfur and lime helped American and European farmers control the bacterial disease vine powdery mildew – a success that marks the first time humans truly gained the upper hand in the battle of pest control.

The Color Purple

It was a later 19th century success, however, that popularized the widespread use of chemical pesticides and prompted commercial research into newer, better formulas. In the 1870s, Western pioneers brought the hearty, tasty potato to their new homes in Colorado, unaware that the territory was already home to a virulent beetle that would decide potatoes were its new favorite food. Christened the potato beetle, the bugs quickly broke the bonds of former habitat and flooded eastward, looking for more spuds. Along the way, they decimated potato crops all the way to the Atlantic Ocean. Then, they managed to hitch a ride on a ship and eat their way through Europe as well. But in 1877, the beasts were finally halted in their tiny tracks, thanks to two chemical compounds that became the most famous pesticides of the 19th and early 20th centuries: Paris Green and London Purple. Both were water-insoluble and made from the extremely toxic chemical arsenic. Oddly, both also had ties to then-popular household dyes and paint pigments. Paris Green, invented in the 1840s, got its name after being used to kill rats in the Paris sewers. London Purple was developed much later, in 1872 and was a byproduct of the London dye industry. One of the key ingredients in London Purple, the indigo-derived chemical aniline, was also the base that allowed London chemists to “invent” the color mauve in the 1850s.

 

 

Share this post :

Advertisements