Then the citrus tree got them. They killed my poinsettia outdoors. Then the crape myrtle got them. The foliage is turning black.
White flies can be a persistent, irritating problem.
Sooty mold is a black fungus that grows on the excretion of insects such as aphids, mealybugs, soft scales and immature whiteflies. These pests have piercing-sucking mouthparts, which puncture the leaf and suck the plant juices. Whiteflies feed from the underside of the leaves so that is where treatments should be applied. The active feeders are the immature nymph whiteflies, which are light green to whitish and somewhat transparent. The newly hatched nymphs insert their mouthparts into the undersides of leaves and then remain stationary throughout the remainder of their immature life stages.