Before the 1930s, insect infestations tended to be isolated. Insecticides available at the time were colorfully named but largely ineffective which didn't matter so much since the bugs weren't that bad. All of that began to change during the 30s.
People who moved to North America brought with them European farming practices. Most farmers supported themselves and few others. In 1790, only 3.3 percent of the American population lived in cities. So, farmers produced most of their crops for home consumption rather to sell to the cities. Farms raised a wide variety of crops and livestock.
By 1930, farmers made up only 21 percent of the labor force. So it began to make economic sense to produce more food than your family need and ship the excess on the burgeoning transportation system to urban markets. The pressure was on to specialize in a few cash crops. It became increasingly clear that if you grew a lot of corn or a lot of wheat, you could make a lot of money when the price was right.
Beginning in the 30s, a few farmers tried to specialize in one cash crop. Most farms in the 30s had one field in corn, another in wheat, and maybe another in oats for the horses. By the 1950s or 60s, entire regions specialized in one of the cash crops producing a monoculture.
What did that move to monoculture agriculture mean to the insects? Unbroken fields with mile after mile of the same plant provided ideal feeding conditions for the insect pests that liked to eat that kind of plant. Beginning in the 1930s, there was a greater need for a better insecticides.
In the 30s, the chemicals that most farmers used were based on the ancient poison arsenic. They were named for their colors. Paris Green was the most popular brand. Scheele's Green was a close cousin. Both contained copper as well as arsenic. London Purple was calcium arsenite and was a byproduct of the London aniline dye industry. Later, chemists added lead to the arsenic compounds, and for the first half of the 20th Century these were the most popular insecticides.
Millie Opitz (left) remembers mixing "arsenic of lead" with sweet banana oil to attract the grasshoppers and spreading the mixture from the back end of a truck. She says it worked, but it was an inefficient way to distribute the poison.
Stan Jensen (right) remembers many of the same methods, and he remembers, "it wasn't very effective at all." So his dad and others tried to scoop the hoppers up with shovels.
Walter Schmitt remembers some farmers gave up on chemicals and tried to get the hoppers to jump into a shiny tank mounted on a tractor. In the bottom of the tank was diesel fuel that killed the insects.
In 1934 farmers in the U.S. used the following insecticides
- Arsenicals, 80-90 million pounds
- Sulfur, 73 million pounds
- Kerosene, 10 million gallons
- Mineral Oil Emulsion, 40 million pounds
- Naphthalene and paradichlorobenzene, 21 million pounds
- Pyrethrum, 10 million pounds
- Nicotine sulphate, 2 million pounds
- Rotenone, 1.5 million pounds
The problem with all of these methods is that they were largely ineffective and the chemicals were potentially toxic to humans and other species. Yet, the farmers continued to use them because they didn't have anything else.
Written by Claudia Reinhardt and Bill Ganzel, the Ganzel Group. First written and published in 2003.