Q: I have these small white specks on the back of my magnolia leaves. Can you tell me what they are and will they harm my magnolia?
A: At first I thought it might be some sort of tea scale but a closer look made me realize it was the pupa stage of some insect. I knew we probably needed to be concerned because there were so many of them. Beneficial insects seldom have large numbers of pupa; but destructive insects often produce abundant numbers of offspring. The type of insect was difficult to identify because most insect photos show the adult and sometimes the larvae or nymph stage but they seldom include the pupa stage. As I was examining the specimens under a scope which includes a light some of the insects began to break out of their pupa because of the intense heat. These tiny (about 2mm), winged insects showed no overt markings to assist me with identification. So, I sent photo samples to Dr. Lyle Buss from the University of Florida. He identified them as male tuliptree scales (Toumeyella liriodendri (Gmelin) (Homoptera: Coccidae). Guess what, insect photos usually don’t include the male scale either! The females are globular (a bit smaller than a pea) and are found on the twigs and/or main rib of the leaves. The males go to the back side of leaves. Adult male tuliptree scales are winged with a pair of filaments projecting from their abdomen. These scales produce a lot of honeydew which will result in sooty mold covering the leaves and stems, which is often a clue to an infestation. Tuliptree scale can be damaging to the trees sometimes killing only branches but if left unchecked the whole tree can be destroyed. These insects are very common on magnolias and yellow poplars (tuliptrees).