Mealybugs Theo 24 October 2022



Mealy Bug

Mealybugs are sap-sucking homopterans that are related to aphids and whiteflies. They feed in the vascular tissue of plants drawing nutrients from the phloem. Injury occurs directly from feeding activity resulting in chlorosis (decline in vigour), and from the excretion of honeydew that is conducive to growth of sooty mold (aesthetic injury). Additionally, some species inject toxins into the plant causing leaf malformation. There is also a root mealbug (Rhizoecus spp.) that lives in the soil and feeds on the roots of hte plants. Yellow foliage and/or slow growth are indicators of root mealbug injury. Examination of the rooting media can detect the presence of root mealybugs.

Key to successful control of mealybugs is early detection. Examine plants regulary for signs of mealbug activity such as the presence of honeydew, waxy white deposits, and sooty mold. Most mealybugs have several generations per year and, depending on the temperature, may require weeks to months to devlop from eggs to adults. Adult females are the easiest life stage to identify. They are wingless, grayish insects up to 5mm long with segmented odies covered with cottony wax. Applications of insecticides before mealybugs become established result in higher levels of control.