Aphids can be a big problem when it comes to gardening, especially if there’s a large number of their population. They suck the juices of the leaves, buds, or stems, causing the yellowing and weakening of plants. Their reproduction is also extremely fast, which can complicate infestation control.
Considering these facts, it’s essential to explore some methods that can prevent your garden from being ruined by these 1/8-inch-long insects and protect your plant’s health.
The chemical control of aphids is a great alternative, especially if you are dealing with a large infestation, and have explored other options.
It takes a lot of knowledge to control aphids using chemicals, and in this article, you’ll find every detail necessary to manage these pests.
Chemical Control of Aphids: 6 Best Available Options
Aphids excrete large quantities of sticky honeydew, which can cause the growth of mold and attract ants.
Introducing natural enemies and predators in the garden is an advantageous way to sustain your plants’ health, but this method of control has proven insufficient when there’s a severe infestation, especially when dealing with aphids that carry plant vectors.
In this case, the chemical control of aphids should be considered. This method consists of using chemical substances to kill plant lice. Still, they can destroy beneficial species, so it’s crucial to use them only when needed. Ensure to read all the information on the label prior to application.
Insecticidal Soaps and Oils
The least damaging and toxic method of the chemical control of aphids is through use of insecticidal soaps and oils. They coat the aphid’s exterior and cause it to suffocate.
Since these chemical insecticides can be phytotoxic to drought-stressed plants, it’s recommended to only apply them when the temperature is below 90°F. They present low acute toxicity to humans, pets, and wildlife, being only toxic to fish.
We’ve covered extensively how you can use soapy water and oil to kill aphids, so don’t forget to read that content.
Insecticides with Pyrethrin
Another effective method of the chemical control of aphids is insecticides that contain the active ingredient pyrethrin. Aphids will see their demise (and meet their maker) after this chemical is applied.
Products with pyrethrin will only cause damage to predators or natural enemies that directly encounter the substance. If sprayed onto the undersides of infested leaves, and a lady beetle, for example, lands on an opposite leaf, no harm will be done.
These are toxic to bees when contact is made, so be careful. Since bees aren’t active at night, dosing infected plants during this period is a safer option.
Learn how to get rid of aphids on your plants by using a combination of factors.
Azadirachtin is an excellent option if you’re struggling with larvae or growing bugs. This botanically derived chemical inhibits the shedding of the exoskeleton and, when mixed with entomopathogenic fungi or bacteria, is lethal to plant lice (another moniker for aphids).
This happens due to the time of contact shared with the insect’s exoskeleton and the pathogenic organism, enabling the fungi or bacteria to grow, and infiltrate the aphid’s body.
Please read the label of insecticides with azadirachtin to know how to apply it correctly.
Do you have ornamentals in your garden that are infested with aphids? A systemic insecticide may help with your situation, if oils and soaps didn’t.
Using this type of chemical control of aphids include using the active ingredient imidacloprid. When applying it, however, be careful, as it can harm pollinators and predators.
To ensure it has the least impact on important insects, opt for drench applications to the roots instead of spraying on the leaves. Thus, the plant will directly consume the product, and it won’t cause any damage to other insects that would otherwise land on the plant.
You can also apply home-use soil imidacloprid diluted with water on the tree base or plant or hire a professional applicator that will use soil injectors, providing better control with less runoff potential.
Another active ingredient in this type of chemical control of aphids is dinotefuran, a neonicotinoid. This type of ingredient represents moderate harm to humans, as it can be absorbed through the skin. It is highly toxic to aquatic organisms and bees. This makes it vital, then, to always read the instructions, as this will reduce the chemical’s harmful effect on you and your crops.
More aggressive and populated infestations require a more robust chemical control of aphids, like formulations with permethrin, acephate (to nonfood crops), and malathion. Malathion is more effective when compared to the use of soaps and oils. Still, they are also more damaging to the environment, killing bees and other natural enemies.
Taking that into consideration, avoid the use of these products with lower populations, and don’t overuse them in the long term, since repeated applications can result in stronger resistance to their formulations.
Insect Growth Regulators
Insect growth regulators (IGRs) are also excellent alternatives for the chemical control of aphids in extreme cases. Methoprene is a representative chemical of this type of product, and it acts as an insect hormone, changing the growth development of the insect.
By doing this, the speed of reproduction will slow down, and the egg-laying or hatching will start to disappear. Insect growth regulators represent low acute toxicity to humans and domestic animals but can be damaging to aquatic invertebrates.
Always choose the more suitable product for your situation, apply it sparingly so that it won’t cause any harm to your garden or greenhouse, and read the label before using them.
Chemical Control of Aphids, Conclusion
It’s essential to try different methods before using chemical control since they can be toxic to humans, pets, and even plants. Once you’ve attempted natural ways to expel plant lice without success, resort to the chemical control of aphids and always follow instructions on the labeling.