Populations of some scales can increase dramatically within a few months, such as when honeydew-seeking ants or dusty conditions interfere with scale natural enemies. Plants are not harmed by a few scales, and even high populations of certain species apparently do not damage plants.
Soft scales and some other species excrete honeydew, a sweet, sticky liquid produced by insects that ingest large quantities of plant sap. Sticky honeydew and the blackish sooty mold growing on honeydew can bother people even when scale populations are not harming plants.
This is a free publication that you can access as an HTML web page or download as a PDF document.
The PDF version of this publication requires the free Adobe® Reader. You can download a free copy of the Adobe® Reader from Adobe Systems Incorporated.