A Simple Solution? Not So Fast
Garden pests can be extremely frustrating. You work hard to ensure your plants grow healthy and strong, and then pests barge in, eating the fruits of your labor! Pesticides—which include insecticides, fungicides, and herbicides—promise results. They claim they'll get rid of the bugs so you can enjoy summer's bounty—all good, right? Not so fast. Here are nine ways both conventional and organic garden pesticides could actually be making your pest problem worse.
Insecticides Can Stimulate Pest Reproduction
When not applied in the correct doses—or at the correct time in an insect’s life cycle—insecticides may actually stimulate reproduction. For example, in arthropods (which include spiders, centipedes, millipedes, beetles, ants, and grasshoppers), less-than-lethal amounts of insecticides can increase egg laying, resulting in an infestation bigger than the one you originally sought to squash.
Pesticides Can Lead to Resistance
Even when applied properly, pesticides can lead to resistance. Over time, the pests you're trying to eliminate can evolve to overcome the chemicals you're using. As well, low doses of pesticides can affect the development, survival, and reproductive processes of insects that you didn't intend to target. In the end, your garden could wind up in even worse straits, menaced not only by the initial, now resistant invaders, but also by a thriving population of insects that hadn't been a problem before.
Insecticides Destroy the Good Guys
You may not intend to harm any insect apart from the one that's eating your prize tomatoes, but that dose of pesticide you apply will kill insects indiscriminately—including beneficial bugs that help keep pest populations in check. As a result, once the effectiveness of your insecticide wears off and the pests return, you may not be able to count on beneficial bugs like ladybugs, lacewings, and predatory wasps to come to your rescue. Is the answer to use more and stronger pesticides? No! Instead, learn to identify insect pests, become familiar with the beneficial bugs that feed on them, and try to encourage the natural ecological processes that keep destructive critters at bay.
Related: 12 Bugs You Should Never Kill
Pesticides Can Encourage Secondary Pests
Even if your use of pesticides eliminates an initial infestation, once the beneficial bugs vanish as well, your garden becomes a target for a secondary invasion. For example, say you manage to wipe out the spider mites that were eating your cucumbers. Well, in the process you may have destroyed your garden's ladybug population. The disappearance of these important predatory bugs opens the door to secondary infestations of whiteflies or aphids, which the ladybugs would have eaten if you hadn't killed them off.
Your Pesticide Use Is Impacting the Birds
Birds eat bugs, which makes them helpful allies in the garden. But insecticides can hurt these feathered friends. In fact, increased pesticide use has led to “statistically significant reductions” in bird biodiversity and population, which means there are fewer birds flying around, including birds who would eat pests in your garden. The result? A vicious cycle of more pests, increased pesticide use, and declining bird populations.
Pesticides Could Exacerbate Carpenter Ant Colonies
If you have a carpenter ant infestation, spraying insecticide could cause them to split up and create separate colonies, which would only make your pest problem worse. Also, keep in mind that many insecticides are designed to eliminate only single-queen colonies, whereas some species, such as the invasive Argentine ant, have numerous queens. Using such pesticides on these species can actually make your ant problem worse. The best solution? Find and eliminate the nest.
Pesticide Use Can Lead to More Flies
Dung beetles offer a pesticide-free defense against flies. They feed on the feces of livestock and wildlife, thereby helping to eliminate material that would otherwise attract flies and maggots. Unfortunately, pesticide use—particularly long-term use—is killing dung beetles, which is allowing fly populations to increase.
Insecticides Hurt Pollinators
Bees play a crucial role in promoting the flowering and fruiting of many plants, but bee species have been experiencing steep declines, and pesticide use is proving to be one of the greatest threats to their survival. Insecticide, herbicide, and fungicide are all harmful to bees and may cause “widespread disruption” of bee behavior that can lead to colony collapse. Avoiding pesticide use will help protect bee populations, which will in turn help your garden thrive.
Insecticides Hurt Other Animals That Eat Insects
Insecticides not only affect insect populations, but they can also harm animals that rely on insects for food. A single bat, for example, can eat up to 1,000 insects in just one hour. But these helpful mammals are “particularly sensitive” to pesticides, which endanger their existence. Remember: Nature is a complex, interconnected series of systems; if you eliminate one species, you can negatively impact many others. So, the next time you notice something munching on your lettuce, don't reach for an insecticide. Instead, take measures to correct conditions that can stress plants and lead to infestations, and learn about nontoxic solutions for ridding your garden of destructive bugs.
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