APHIDS

Aphids are small insects in the superfamily Aphidoidea, that feed by sucking sap. They come in many colors although common ones are green, yellow, or black. They produce a lot of sticky honeydew which ants feed on. 9/10 times if you see ants on a plant, they are not there to hurt the plant, they are there to farm aphids. Aphids are an easy pest to treat and only cause a lot of damage if they are present in high numbers. They have an interesting reproductive strategy where the females can give birth to live nymphs who are already pregnant themselves.

Non pesticide options:

  • Water pressure (syringing) – Aphids tend to cluster together and it is easy to blast most of them off with a water hose. Works great for minor infestations

  • Horticultural oil / dormant oil - This is a mechanical pesticide. It kills aphids by suffocating them and so there is no way to develop resistance to it. It is direct contact only and has no residual effects. Horticultural oil and other oil-based pesticides can damage leaves. They can cause burning or other damage if applied when temperatures are high (80-85F or higher) or if the leaves are sensitive. Always test it on a couple leaves first before spraying a whole plant

    Horticultural oil can also be mixed with many other pesticides to increase their effectiveness

  • Soapy water - Real soap like dr. Bronner’s or safer insecticidal soap. Follow directions on the label for dilution ratio. Only kills on direct contact with no residual effect

  • Stickytraps–These will not control or suppress aphids but provide early warning

Insecticides 

  • Azadirachtin – Derived from neem seeds, acts as an antifeedant and insect growth regulator. Absolutely destroys aphids and is organic and safe for food crops. See “Azadirachtin” in thrips section for more information

  • Bifenthrin – a synthetic pyrethroid with a broad range of controlled pests including termites and spiders. One of my favorites, bifenthrin is effective at controlling most common pests and even suppresses spider mites. In addition to plant applications it makes a good barrier spray for around the home. It is inexpensive too, you can buy it as Bifen I/T in a 16oz bottle for about $22

  • Permethrin – another synthetic pyrethroid with a smaller range of controlled pests. It is the active ingredient in dog flea collars and human lice medicine but it is a neurotoxin to cats so if you have cats keep them away from treated areas until dry (~12 hr). Can be found online for about $10

  • Imidacloprid – Imidacloprid is a systemic neonicotinoid that kills everything except for spider mites and hard scale. It is available in granular form that is applied to the soil and provides protection for 90 days. I highly recommend this for all indoor plants. See “Imidacloprid” in the mealybug section for more info

  • Almost any other insecticide – Aphids are susceptible to most contact and systemic pesticides you would have on hand to control other pests