Why Pesticides are Such a Bad Idea

At Bee City Los Alamos, we often talk about how pesticides are one of the most significant threats to pollinators. By pesticides, we mean any chemical applied in our gardens and landscapes to kill something, be it an insect, a fungus, a weed, etc. Many people who are aware of pollinators as an emerging environmental concern also recognize that pesticides pose a serious problem. But, why are they such an issue?

Many of us love butterflies, birds, and honeybees and are overjoyed to see them in our gardens. I have been a professional gardener for years.I have worked with many different people and gardens and I find that, while we cherish certain wildlife, we are often unaware of the impact of the sprays we use to kill aphids, caterpillars, and other unwanted creatures. One of my favorite garden friends, during a recent clean-up day, proudly opened a cupboard to offer me a staggering array of poisons to eliminate the caterpillars chewing his zinnia leaves. I gently explained that these poisons would also kill the butterflies he loves, since caterpillars are butterflies at a different life stage. Additionally, the poison could harm the birds that rely on insects for food. Birds need caterpillars, mosquitoes, aphids, ants, and other insects for their survival and that of their young. My friend was shocked, having no idea that the poisons he had purchased could harm so many creatures. Many people are unaware of the broader impacts of these chemicals.

Similarly, many people buy rat and mouse poisons, not realizing that these can also harm owls and hawks that rely on rodents. This is just the tip of the iceberg. We often unknowingly disrupt the balance of our ecosystem by killing insects and animals we find unpleasant, like spiders, ants, mice, wasps, and rats. Yet, all of these animals play crucial roles in the ecosystem. For example, spiders help control fly and mosquito populations.

Nature generally keeps things in balance if we stay out of the way. Due to many different factors, including our own attempts to eliminate the creatures we have decided are unpleasant, things can get out of balance. Certain “pests” can gain the upper hand and start making a mess of our gardens or trash cans. In this case, we recommend that you not reach for poisons but, rather, choose more benign options like live trapping or reducing food sources near the house. Using chemical poisons is rarely the best option, especially for the average homeowner. Skilled herbicide applicators are trained to use these chemicals only when absolutely necessary and only when they are the only viable tool to protect important ecosystems.

Recently, I spoke with someone at the Bee City booth, during Los Alamos Mainstreet’s ScienceFest event, who loves pollinators and is planting flowers and shrubs to attract butterflies and bees. She was concerned about aphids and insects nibbling the plants and assured me she “never used pesticides,” but was using Dawn dish soap to get rid of aphids and caterpillars. I have been an organic gardener for over 35 years and remember using homemade “non-toxic” sprays for aphids until I realized how these sprays work. Many insects are soft-bodied and breathe through their skin. Dish soap coats their skin and suffocates them, affecting many desirable caterpillars and other soft bodied pollinators. The soap can also harm birds and remove the protective coating on plant leaves. Instead, washing aphids off with plain water or removing them by hand is often effective and less harmful.

We tend to think that if something is homemade and seems harmless, it must be safe. However, homemade solutions can sometimes be more dangerous to our soils, plants, and wildlife than store-bought formulations. For example, a popular homemade weed killer made from salt and white vinegar can be deadly to soil organisms essential for nutrient cycling. Similarly, using bleach to kill moss and weeds can harm soil, animals, and people.

At the end of the day, there are no easy fixes. In fact, often no fix is really needed at all. Is it really a big problem if the caterpillars are eating the leaves of some of our shrubs? Will it actually kill the shrub? Asking ourselves how much of a problem the damage really is, before we set about destroying every insect in our yards, is a first step. Correctly identifying the insects before deciding to kill them is another important step. There are, certainly, some very nasty insects that cause significant damage to our crops and ornamentals and it is wise to learn to identify them and then use the least toxic means possible to keep them under control. When we have a knee jerk reaction to every insect that is on a plant and spray broad spectrum pesticides, we end up killing both the good and the bad players. Insect populations are declining worldwide, and without insects, the entire food web begins to unravel. Fish, birds, and small mammals all rely on insects for food. Over 85% of all flowering plants depend on insects for pollination. When we plant pollinator plants and then use chemicals to kill insects, we may unintentionally do more harm than good.

Let’s start to be creative and observe our gardens before taking action. Are those aphids really harming our plants, or are they feeding baby hummingbirds that need insect protein? Can we manage pests by knocking them off plants with water or our fingers? What about making a game out of hunting down squash beetles? You could look up caterpillars on iNaturalist and join our Citizen Science project to log local pollinators. You might discover Swallowtail caterpillars or even Monarchs!

Pause before you spray. Consider the broader impact of that seemingly small gesture. While you may not love every insect or mammal, they all have roles to play in our ecosystem. For example, flies help break down waste, and mosquitoes are a primary food source for many birds and fish. Everything has a purpose. This month, and throughout the year, let’s learn more about the creatures around us and how they contribute to our planet’s beauty and richness. Thank you!

Please sign up for our Bee City Los Alamos newsletter to stay in touch with all of the great work we are doing for our pollinators. You can find the sign-up form at the bottom of our home page at: beecitylosalamos.org

To learn more about pollinators and how you can help save them, visit xerces.org.