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History of pesticides includes a healthy dose of ‘tobacco tea’

Simply put, they are all pesticides: insecticides, herbicides, fungicides, rodenticides, algaecides, miticides and so forth with all the “cides.”

The term “cide” is defined as “to kill” or a “substance that kills.” And that is mostly true in the realm of products designed to keep pests from damaging plants, animals and structures. But the term “pesticide” is used to include everything else mankind uses to prevent losses to pests.

Some pesticides don’t actually kill problem pests but stop reproduction so the pest population dwindles over time. Even products that merely repel pests are regulated by the Environmental Protection Agency and shelved at stores right along with pesticides. By law, repellants are pesticides.

Whether a pesticide substance is a lab-generated chemical compound, a lab-multiplied natural organism or a full-fledged organic product, its purpose is to prevent damage to a specific host.

I noted years back many people used the word “pesticide” to refer to something that got rid of only insects. When I asked what had been tried thus far to solve a bug problem, the answer was often “I sprayed Spectracide.” For the record, Spectracide is the name of a company that markets a variety of pest control products. Initially, its only product was the widely used insecticide diazinon, which is no longer made at all.

People who study such things say the first use of pesticides was back about 2500 BC when sulfur compounds were found to be pretty good bug killers and even helped with plant diseases.

At some point, somebody somewhere figured out tobacco was also an effective insecticide.

I remember when “tobacco tea” was highly recommended as an organic pesticide. Actually, it’s the nicotine that kills insects.

The reason nature puts nicotine in some plants is to keep insects from eating them. Tobacco has the highest level of nicotine, but other plants in the nightshade family contain some nicotine. Among vegetables, eggplant has a nicotine level much lower than in tobacco but a bit higher than two of its cousins, potato and tomato.

At some point, sulfur and tobacco liquid were combined into nicotine sulfate, an insecticide that was tough on insects. However, it eventually carried the “Danger” and skull and crossbones —Environmental Protection Agency indication for risks to people if ingested. Nicotine sulfate was still available up until 2014, but it is now banned.

Natural sulfur and natural copper are organic pesticides, whether the target is insects or fungi.

The long-ago outlawed insecticide DDT is an example of how we humans have the ability to study and learn over time.

Probably not many people know a Swiss scientist was awarded the Nobel Prize in Medicine for his research using DDT to prevent two major diseases among soldiers during World War II. Typhus spread by lice and malaria spread by mosquitoes were controlled by DDT. The insecticide had nearly no effect on humans and it was cheap and very persistent.

It was that persistence in the environment that eventually led to us getting rid of the cheap, effective insecticide DDT.


Terry Rector writes for the Warren County Water and Soil Conservation District.