There is sooty mold on the silver palm just outside the office door.

Here is what a clean frond looks like:

It makes the plant look terribly unsightly, as if the ashes from a nearby volcano have just drifted over.  

If the palm becomes too heavily coated with sooty mold, photosynthesis will be reduced and it will decline in health.  

In this particular case, it is the droppings from green scale on the gumbo limbos above the silver palm that allow the sooty mold to lead such a prosperous existence.

The green scale thrives on the tender young stems of many types of trees and shrubs.  The scale multiply quickly and indiscriminately excrete their "honeydew."  This substance drifts through the air and lands on whatever is below.  My advice is to walk through there quickly and don't look up (especially, don't look up with your mouth open).

Introducing our hero, the mealy bug destroyer.  You might mistake this champion for a bird dropping, or a mealy bug pest, but this is actually the larva of a ladybug beetle that eats the scale.

It was introduced from Australia in the 1890s, to treat mealy bug on citrus, and was very successful in that.  In lean times, when not many mealy bugs are available, the mealy bug destroyer will eat scale and other insects.

One easy way to tell the difference between the two is that mealy bug destroyers crawl around a lot, while mealy bugs tend to stay in one spot once they get there.

Here is a link to a photo of a typical mealy bug infestation.  

Here is a large population of mealy bug destroyers on the underside of a palm frond.  Look for them in your own yard.

Once you know what they are, you will develop some affection for them.  

They are so cute, like little poodles.  But instead of grabbing the remote and pushing you off the couch, like real poodles, these furry beasts are happy to stay outside, slurping the scale off the branches of your favorite trees.

Include them in your integrated pest management strategy.