Poinsettias are such cheerful plants! In a variety of colors, some in vivid hues, some newer varieties with variegated leaves, and a few dwarf kinds such as ‘Freedom’ and ‘Pink Peppermint’, they signal the holidays!
Many of us have a least one of these Euphorbias, their botanic name, on display in our homes during this season, with some going ‘Poinsettia proud’ and decorating entire structures with them. For the most part, they are easy-going house guests, requiring a sunny windowsill and adequate but not over-generous water.
Occasionally these plants are brought into our homes carrying a hitchhiker, a tiny insect that is attracted to poinsettias like ants on spilled sugar. These little, snow-white insects, properly called Trialeurodes vaporariorum, are often not noticeable until we bump into our poinsettia, causing a cloud of the delicate things to fly off the plant for a few seconds, then settle back down. While on the undersides of poinsettia leaves, these critters use sucking mouthparts to remove “blood” (actually sap) from veins in the leaves. Usually not noticeable until a sticky, slightly shiny coating appears on the leaves, whiteflies can become very numerous pretty quickly.
Whiteflies enter our homes several ways, but the most common is via infested plants. Therefore, before introducing a plant into your home, check it carefully for signs of hitchhikers! Lift up leaves and look at the undersides – these bugs are good at hiding their babies where we don’t easily see them. And once hatched, these insects crawl around as they feed (appropriately identified as the “crawler” stage). Spraying the undersides of leaves with insecticidal soap every 4 – 7 days at this point will help break the whitefly’s life cycle. If adult whiteflies are already ‘on the wing’, yellow sticky traps are an option short of spraying a conventional insecticide inside your home.
For those who develop emotional attachments to their poinsettias but discover the plant has become a whitefly congregation area, the best option may be to compost the plant lest other plants be threatened. Hard to say “good bye” but you may be saving an entire indoor plant population from an insect infestation!
By Sallie Lee, Urban Regional Extension Agent, Alabama Cooperative Extension System. Contact Sallie at firstname.lastname@example.org.
The Alabama Cooperative Extension System (ACES) operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities. ACES is committed to affirmative action, equal opportunity and the diversity of its workforce. Educational programs of ACES serve all people regardless of race, color, age, sex, religion, disability, sexual orientation, or national origin.