Hibiscus: is this normal or contageou s disease, 1 by cindyhib

cindyhib wrote:
Those look like the dry skins of aphids after they have molted, something they do about 4 times on the way to becoming adults. If they don't move, they aren't white flies. A gentle shake of the stem will send a cloud of whiteflies swarming around the plant. There are some white scales that go for hibiscus but they are found mostly on the woody stems and these look to be on the surface of the leaves mostly. This is typical for aphid skins although this plant sure has a lot of them. Check to be sure ants aren't bringing them onto plants in that spot. (Another photo of aphid skins from a univ web site is below)

It's amazing how fast a host of aphids can show up on a plant. Sometimes ants bring them, sometimes they hatch out after overwintering as eggs somewhere on the plant or in plant debris under the plant. In any case a thorough cleaning with water as others have recommended is a good idea, and the Bayer products that contain imidacloprid are great at controlling aphids if you get tired of spraying soap and oil products repeatedly. Surprisingly, aphids are persistent and can be hard to get rid of without using a systemic product. The good news is that this is not a disease and there is no reason not to use that spot if the light and other conditions there are good.

Charles