Mealy Bugs

Garden Clippings for January 25, 2020

Growing tropical plants in our northern homes is a joy.  Indoor plants bring life into our stark living spaces.  Purifying the air is an added bonus.

But just like our outdoor landscape plants, sometimes insects invade, feeding off indoor gardens.  And while many insects pose no threats, some are a source of frustration.

Scale insects can be particularly nasty.  Scale insects fall into two categories: hard shelled and soft shelled.  The first is difficult to detect and their presence often goes undetected until the plant is heavily infested.  Hard shelled scale appears as brown, grey or greenish shells about 1/8” in diameter.  Once settled, they don’t move.  They will attach themselves to a stem and will suck juices from the plants.

Soft shelled scale, called mealy bugs are grey or white insects that resemble small pieces of cotton batten.  They move slowly until they find a place to rest and have dinner.  Like their hard shelled cousins, mealy bugs will slowly feed by sucking juices from plants.  An infestation will not pose a serious threat to plants, but a heavy infestation can slowly lead to a plant’s demise.

Mealy bugs are not easy to eradicate.  Controlling mealy bugs requires patience and persistence.  If your plant has only a dozen or two visible insects, use a Q-tip dipped in rubbing alcohol and individually touch each insect.  You’ll find most are sitting at the base of a leaf stem.  Keep an eye on the critters and reapply rubbing alcohol until the problem is gone.

If it is not practical to tackle the scale insects with rubbing alcohol, spray weekly with insecticidal soap.  If the plant is not valuable and is heavily infested, I’d recommend tossing it into the garbage before the problem spreads to adjacent plants.

Spraying hard shelled scale will do little good as the insects are protected by their hard shells.  If it is feasible, consider pruning the plant back to remove much of the problem.  Bring the plant indoors in May where it can bounce back to vigorous growth.

I have had a few people recommend to me that placing a mealy bug infested plant in the shower and spraying it with a constant spray of water will give success.  Put a plastic bag over the soil to prevent the soil from becoming waterlogged.

Don’t kick yourself for allowing scale insects to come into your home.  They may have come in after spending their summer outdoors on the patio.  Most likely you would have introduced scale by bringing in a new plant sourced from a less reputable supplier, grower or retailer.

The best way to keep scale insects at bay is to keep the host plant healthy.  Provide good lighting, give periodic plant food and don’t overwater.  If your indoor growing environment is less than ideal, prune the plant and do your best to keep it alive until spring when it can thrive outdoors with plenty light, warmth and humidity.