These unarmored scale insects are equally as weird as the rest of their close relatives, but they can walk! I like to think of them as “fuzzy, mobile scales.” The females are wingless, soft, and oval; they create a fluffy, waxy coating, giving them their name “mealybugs.” The males, however, are small, winged insects generally ranging from .1 to .25 inches (.25–.65 centimeters).
These insects damage tomatoes by feeding on their plant saps and secreting a sweet concoction known as “honeydew,” which encourages the growth of sooty molds. They also are known to transmit diseases/
Depending on your area, these are generally active spring through fall. They may be active year-round in greenhouse settings.
You’ll find this family of insects in all temperate and tropical zones around the world and inside greenhouses, even where it’s too cold!
Like with all insects, mealybugs are attracted to areas with plenty of resources such as water, food, and shelter. Tomato plants are an unfortunate favorite of several mealybug species.
Mealybugs can get out of control very quickly, so make prevention a top priority. Check any new plants you bring to the area and quarantine them before planting. Meanwhile, you can eradicate small infestations with cotton swabs and alcohol—just a dab’ll do it! Insecticidal soaps can also be effective, whether homemade or commercially purchased. Several biological controls will work for mealybugs too, but remember that most can fly at some stage of their lives, so it’s best to use them in greenhouse settings where they won’t just fly off. And, as always, make sure you’re not introducing an invasive species when using a biological control such as insects or bacterium.
Mealybugs are often confused with one of their predators, mealybug destroyers (a beetle in the genus Cryptolaemus). While the adults are beetles, the larvae resemble mealybugs due to being equally “fluffy.” Make sure you know what bugs you have before treating!