MEALYBUGS

Mealybugs are soft-bodied insects in the family Pseudococcidae that feed by sucking sap from plants. They also excrete honeydew like aphids which leaves a sticky residue and can lead to black sooty mold. The mealybug life cycle takes approximately 2 months from egg to maturity. Once mature a female can lay hundreds of eggs that hatch within a few days. They are most mobile shortly after hatching. Mealybugs can infest both the foliage and the soil so if they seem to keep coming back after treating them you probably need to treat the soil too. They are frequently found hiding in new growth when there are only a few of them. In larger numbers they can cause plants to shed leaves or even die.

Non pesticide options:

  • Rubbing alcohol – For small infestations you can treat mealybugs by applying rubbing alcohol directly to the individual pests with a cotton swab. You can also dilute the alcohol to 25%-50% and apply it as a spray but you need to test this on a small portion of the plant first since it is possible to burn the leaves. Alcohol only kills on direct contact and has no residual action

  • Insecticidal soap – Also kills on direct contact with no residual action but less effective than alcohol

Insecticides 

  • 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). It can be found at home depot or lowes under the brand name Bonide eight in a 32oz container for about $20

  • Imidacloprid – Imidacloprid is a pesticide that works too well for its own good. If you have heard of neonicotinoids killing bees, it’s this stuff. By 1999 it was the most widely used pesticide in the world but has since been banned in the EU. However, used correctly it is one of the safest and most effective systemics available. It is labeled for use on greenhouse plants or indoor plants, neither of which will harm bees. Never use it on an outdoor plant that will be flowering in the next 3 months although it is good for treating outdoor plants when you bring them inside for the winter to kill any hitchhikers

    It is available in granular form which is applied to the soil then watered in. It kills EVERYTHING except for hard scale and spider mites, including soil borne pests like thrips, fungus gnats and mealybugs and lasts for 90 days between applications. Since it is applied via the roots it isn’t instant and is better as a preventative than to treat heavy infestations. All indoor plants should be treated with this as a systemic, as soon as you pot them up or bring them home for the first time (reapplying at least once or twice a year ensures your plants will be pest free indefinitely) 

    It is available from amazon sold as Bonide systemic houseplant insect control in an 8oz container for about $20.

     If you have a lot of plants, purchase Marathon instead. It is more expensive up front, but much cheaper per application. It comes in a 5lb container for $110 and is 1% vs only 0.22% for the Bonide brand