Spices Used as Insecticides

 A new study presented at the American Chemical Society's 238th National Meeting suggests that the essential oil of common spices, including mint, clove, thyme and rosemary, may act as natural insecticides.

For the last 10 years, the scientists have tested the effects of various essential plant oils. The research was funded by EcoSMART®, a botanical pesticide company based in Alpharetta,Ga.

The authors found that some oils may kill pesky insects, while others may repel them. Organic farmers have already begun using natural, spice-based commercial products to help protect spinach, tomato and strawberry crops against aphids and mites.

The researchers note that there are potential pros and cons of using natural, plant-based insecticides. These products are readily available, and it is unlikely that insects will become resistant to the essential oils. They are also safer for farmers than conventional pesticides.

However, because the oils evaporate quickly and degrade rapidly in sunlight, they need to be re-applied more often than conventional insecticides. Also, spice-based insecticides are less toxic than conventional products, which means that higher concentrations may be needed to control pests. Research is underway to discover potential ways to overcome these shortcomings.  

Other studies are testing the essential oils of different plants, including lavender, basil, bergamot, patchouli oil, and at least a dozen other oils from exotic plant sources in China

For more information about insecticides please visit Natural Standard’s Environment & Global Health database.

Comments

[GB]

The most important finding that this study reveals is that if the ongoing research to overcome the shortcomings of the use of natural pesticides, the soil that has been damaged by thousands of years of man-made pesticides will be given the chance to recover. Not only that, but diseases linked to exposure to pesticides, such as Farmer's Lung, Parkinson's disease and flu-like syndromes, will also no longer be a threat to the farmers' health.

[jk]

The consumer of the crop is at less of a risk of ingesting harmful substances that have been linked to cancer too. Besides that, the pesticides that seep into the ground where animals graze or nest and then humans consume will also have an impact on human health.

[Cass]

It's great to hear that natural alternatives to pesticides are in the works. I've always heard gardeners tell others to plant certain flowers near their vegetables (like marigolds, for instance) which for some reason, help keep insects away. Not sure that works on a big scale, too?

People can be poisoned by pesticides in a number of ways, but the scariest to me seems to be through contaminated water. It seems so easy for chemicals to leech into ground water, which eventually runs into a water source of some kind. The effects -- as most people know -- are serious and range from dizziness to vomiting, and respiratory and neurological damage. The World Health Organization notes that even "low-level exposure to pesticides has been linked to cancer, birth defects, and damage the nervous and the functioning of the endocrine system," which makes this research even more valuable.

[gdmd]

I know that man-made insecticide use is decreasing in the United States. However, it is increasing in other countries. It would be beneficial (globally speaking), if the herbal insecticide research was applied internationally. This would have a huge impact on every living thing.

[kris]

While it is true that conventional pesticides can be harmful to human and animal health, this article discusses how higher concentrations of the spice-based insecticides are necessary to control the pests. So I wonder if this higher concentration is also harmful and if it is significantly less harmful than the conventional pesticides.

[Mary F.]

It’s great to see that a botanical pesticide company sponsored this research. Although it’s cynical, I always think of research sponsors as either the government or a big, bad industry giant such as a pharmaceutical company. I see it as positive that a smaller, eco-friendly company can support research efforts. It might even be telling of a real consumer switch to products that are people friendly and environmentally friendly.

[T. Miller]

I wonder if some plant extracts are only effective pesticides for some plants. For example, perhaps mint oil repels mites on spinach crops, but not strawberry crops. Perhaps if the spice, the pest and the crop that needs protecting from the pest are all native to the same area, the spice would be a more effective pesticide. I also wonder if the mint oil might change the flavor of the crop it is applied to.

[P.J.]

Perhaps the next step in this research is to “chemical-ify” these spice oils. In order to prevent them from breaking down in sunlight, I would imagine some complex chemistry must be applied to the spice oils. Also, if the spice oil is needed in concentrated amounts, a lot of the spice might need to be grown. This could take up a lot of land and resources. It might not be financially viable.

[AA]

I wonder whether people with allergies or sensitivities to plants or spices will have to avoid foods treated with spices as insecticides. The Natural Standard Web site has a lot of information on spices that are traditionally used for cooking, and there is information about safety. It says that thyme can cause skin irritation, even if diluted, and the rosemary monograph reports that there was a case where a “subject had occupational asthma caused by several aromatic herbs, including thyme, rosemary, bay leaf and garlic.” I’m sure that insecticides can also cause allergic-type reactions and toxicities, probably more so than an herb, but it is still something that should be tested and considered before widespread use.

[abg]

It seems like there isn’t much financial concern about using herbs and spices as pesticides, but as delivery systems are developed to keep them from degrading so quickly, costs could easily rise. Foods that are considered “organic” are already a bit expensive and adding to this could draw a line for consumers looking to save money. In theory, it seems like using herbs that grow readily would be cheap, but delivery systems designed to make an application last longer would definitely drive prices up. Putting these substances into liposomes or other complicated chemical structures, or mixing them with other chemicals could turn this “natural” or “organic” alternative into a luxury item for a specific consumer group. If a cost-effective method can’t be developed, then maybe we should stick to planting flowers around the crops or just using the commercially available products we have now.

[rgorensh]

Organic farming is known for being more expensive to produce. If, according to this article, essential oils of such herbs as mint, clove, rosemary, thyme act as natural insecticides, they may be a cheap alternative for organic farmers. It seems that the oils were applied to the crop in a concentrate form. I wonder whether the same effect can be achieved by simply planting these herbs among the crop one is trying to protect. However, that may lead to some unexpected side effects. Further research is definitely needed.

[V. Stein]

After reading this blog post it got me thinking about how many pesticides I consume while eating fruits and veggies. I never really thought about the pesticides that may be on my produce, and I hardly ever wash it. So I decided to do some research and found out from the National Pesticide Information Center (NPIC) that all I have to do is rinse my fruits and veggies underneath running water for a couple of seconds to rid them of almost all the pesticides on them. (Produce with waxy or rough surfaces may require additional scrubbing.) Now that I know how easy it is, I am going to wash all my fruits and veggies before eating them.

[Sheila]

I wonder if planting mint, clove, rosemary or thyme in my garden next to my vegetables would help deter any pests, or does the oil have to be released? I may just plant them either way because these herbs and spices smell great and can be used in a lot of different recipes.

In addition, I looked some of these spices up on Natural Standard and realized that they also have medicinal purposes. For example, mint can help a lot with stomach upset and indigestion. Sounds like planting these plants in my garden is a win, win situation.

[Debbie]

I think it is great that researchers are finding alternative methods to protect crops. It will reduce chemical runoff and the amount of chemicals that humans are unknowingly ingesting too. I wonder if the spices mentioned (clove, thyme, mint, and rosemary) have less insects attacking them due to the oils. Also, since these new insecticides would be considered "natural" does that mean that we would not have to wash the produce that was sprayed with these pesticides?

[jen]

On the thoughts AA had on individuals with allergies- I found a few Web sites that are claiming that diluted milk can act as a fungicide for certain plants. Imagine if this became widespread (assuming it does actually work), for those with lactose intolerance, who are vegan, etc.?

[Amiyah]

I would never have thought that spices could be used as insecticides. Considering the contamination risks associated with chemical insecticides, this is definitely a step in the right direction. Further research would be needed in terms of long-term effectiveness (would insects become resistant?) and if longer-acting insecticides could be formulated.

[ASR]

I think it is great to research alternative methods, such as spices, as natural insecticides. Many people do not realize how easy it is for chemicals to contaminate the foods we eat and the land. I would assume that the natural oils of these spices would not pose a threat to the environment (being from a natural source), but if they are to be in a concentrated formulation, would that impact the environment/people?

Also, similar to AA, I wonder if these added oils could cause problems for people who cannot tolerate them. Looking forward to more details in the future.

[paul]

After reading this blog post, it got me thinking about how many pesticides I consume while eating fruits and veggies.

[Tod]

I thought this was a very interesting article. If the researchers can develop more environmentally friendly pesticides that do not degrade rapidly, it would be extremely beneficial. This could help farmers and consumers as well as contribute to environmental preservation by limiting the amount of toxic chemicals getting to the soil.

[stacy]

The first thing that comes to mind when I read that spices, such as rosemary, thyme, mint or basil, are being looked at as pesticides is, “I pay an arm and a leg for these in the grocery store….how are we going to be able to afford this new idea?” Spending some money up front to maximize the way we harvest these spices may be cost effective in the long run since who really knows the extent of how much money pesticides are costing us in healthcare.

[andrew]

Even though the research seems to have been looking at plant oils as the main part to be utilized, I wonder if it would help to grow the actual spice amongst crop fields. I’m not sure if this would be introducing more problems into the situation (such as now the crops have to fight with the spices for nutrients), but maybe having the scent of a harmful plant nearby will help keep the insects away.

The other piece of information mentioned in the article is that several exotic plant sources from China are being researched. Do we know if these species can be grown in all areas of the U.S.?

[Mary]

It is exciting to hear that there is work being done with the use of essential oils as an alternative to insecticides. Harmful insecticides are used so frequently where I grew up that the Lady Bug population has almost been eliminated, which is really sad. As consumers, we need to be more cognizant of what all we are destroying. I’m glad the American Chemical Society allowed a natural option to be presented at their convention. Plus, the use of essential oils sounds like a nice change from the awful chemical smell one is forced to endure when the crops are sprayed. I enjoy the aroma of lavender, basil and patchouli!

[abg]

I wonder if these plants can be crossbred with spice plants the way that fruits are combined. Then maybe the crops will have their own inherent pesticide, like those flowers in the Amazon that repel bugs with their bad smells.

[Eve]

This would be a great alternative to chemical pesticides, since chemical pesticides are not only harmful when exposed to insects, but they're also harmful to humans when ingested. If these botanical pesticides work by repelling the insects, but yet safe for humans to ingest, this would be a great way to produce healthy vegetables. I wonder though, the cost of using these spices in large-scale crops and how we can integrate this into practical uses when chemical insecticides are probably much cheaper.

[Darrell]

What a nice thought. Not only do pesticides harm humans when consumed, but they also seep into the ground water, our wells, our rivers and our oceans; eventually affecting the flora, fauna and humans. The use of natural pesticides may help prevent us from ruining the water supply.