If white insects are clustered on the bark of the plant, they will be Crapemyrtle Bark Scale. They have only relatively recently been introduced to Maryland (they've been in southern states for longer, though are not native) but have spread widely in just a few years, probably helped by the fact that Crapemyrtle are so over-planted in our landscapes. You can learn about this pest (and scale insects in general, plus options for managing them) by visiting the linked page.

The insect pictured appears to be a lady beetle (ladybug) larva (juvenile). Some species have this white, waxy body covering to help them blend-in, and they can look very close in appearance to their prey, in this case the scale. One main difference between the two, other than size since the ladybug larvae will grow larger as they mature, is that the scale are essentially unmoving (not in any easily-detectable way, a least) while the ladybug larvae will roam around and walk off when nudged.

We do not want to kill these larvae because they help control pest insect populations, especially this scale. If you are finding insects trapped on sticky tape, they are probably the "good guys" and not the pest, especially since the only life stage of the scale that would wander around and run into the tape are very, very tiny and need a magnifying glass or microscope to see well, and they do not have a white body coating at that age. We generally discourage using sticky traps for pest insects (aside from unique circumstances like monitoring for scale, which is done differently) because of their tendency to also catch beneficial or harmless insects, plus harm bird feathers if they accidentally touch the adhesive while trying to eat the bugs.

The black substance you describe is sooty mold, a byproduct of the scale population which will go away on its own once the honeydew wears off as the scale are brought under control. Sooty mold can shade plant leaves by blocking some light, but it otherwise doesn't harm plants and will not infect them. Our Honeydew and Sooty Mold web page explains this in more detail. If on hard surfaces, sooty mold can be pressure-washed off if you don't want to wait for it to wear off on its own over time, but on plants you may want to avoid a high-pressure water spray on delicate bark or foliage that may be ripped off (though the latter by itself is not too harmful this late in the season).

Insecticides are unfortunately the simplest and most efficient way to get rid of scale, unless you are okay with removing the infested plant instead. Fortunately, plants with soft scale population outbreaks rarely die, though if persistent, over time (years) the scale could weaken it to the point of some branch dieback. Physical removal of scale is challenging on tall trees that are hard to reach and where scale can wedge themselves into inaccessible bark nooks, but it would help immediately reduce the population at least. Still, removal efforts may inadvertently take some beneficial insects like these ladybug larvae with them, and you would need to be careful so any sort of bark scrubbing doesn't injure the thin bark itself. Some insecticide options could risk harm to the ladybugs or other insects but others will be more targeted. We suggest you work with either a certified pesticide applicator (often found via landscape or tree companies, arborists, or self-employed landscape consultants) or a certified arborist so they can help you choose the most appropriate treatment method for your situation and to make the applications for you. Good control might take well over a year to achieve.

Miri