Mealybug Alert! By Dr. R. Lindquist Dept. of Entomology OSU/OARDC, Wooster, OH Currently there are two main mealybug pest species on greenhouse and interior landscape ornamentals, the citrus mealybug, Planococcus citri, and the long tailed mealybug,Pseudococcus longispinus. Recently, two other mealybug species, the pink hibiscus mealybug, Maconellicoccus hirsutus, and Phenococcus madeirensis, have the potential to become widespread problems on numerous ornamental crops. Mealybugs have in common the ability to feed on a very wide range of host plants. They cause severe problems on foliage plants in greenhouses and interior plantscapes, but can also infest numerous flowering plants. The pink hibiscus mealybug (so-called because when crushed a red fluid comes out) is found now on many of the Caribbean Islands, and is not yet established in Florida. Partly as a result of rapid reproduction and perhaps partly because of pesticide resistance, P. madeirensis has become extremely difficult to manage with insecticides where it occurs – so far mostly in Georgia and Florida. Detection and Sampling Female mealybugs do not fly so the only way they disperse is on plant material, on people moving from one area to another, or as crawlers floating on air currents. Check plant material susceptible to infestation before it enters a growing area to make sure mealybugs are not being brought in. Check stems and leaves for white cottony substances on a regular basis. Look for shiny and sticky areas of honeydew on leaves. Make sure the area is clean following removal of infested plants. Mealybugs may even survive on empty benches between crops! With additional mealybug species now potentially infesting greenhouse and interior plantscape plants it is a good idea to get proper identification. If you find a mealybug infestation and you are not certain of the species, contact your county or state extension specialist(s) for instructions on how to send samples for identification. You can also contact Dr. Lindquist at 330-263-3736 or lindquist.1@osu.edu