Mealybugs and cottony scale are common insects in the Texas Gulf Coast. The two are similar in appearance making specific indentification difficult. They appear in late spring or early summer when the female develops a white, cottony egg sac. The sac can contain over 2000 eggs, which are deposited on leaves and branches of the infested plant.
When hatched, the young insects feed on the sap withdrawn from the leaves, twigs and bark, damaging the plant’s ability to deliver nutrients to itself. The insects cannot completely digest the food, so their excretions are high in undigested sugars. The sticky substance, known as honeydew, coats the leaves below, and provides a medium on which sooty mold will grow.
A heavily infested plant may exhibit leaf drop and twig dieback.
A midsummer application of a professional grade insecticide should be followed by an application of a dormant oil during the tree’s dormant period in late winter to early spring.