Which of the following statements about honeydew is true?

Honeydew is a sugary substance secreted by certain insects, particularly sap-sucking pests like aphids and some scale insects. When these pests feed on plant sap, they excrete this excess sugar in the form of honeydew, which can accumulate on plant surfaces.

The reason that honeydew can serve as a growth medium for molds is due to its high sugar content. This creates a favorable environment for sooty mold fungi, which can grow on the surfaces where honeydew collects. While the molds themselves do not directly harm the plants, they can impede photosynthesis by blocking sunlight from reaching the leaves, ultimately affecting plant health.

In contrast, the other statements do not accurately reflect the nature of honeydew. It is not beneficial for plant growth; rather, it can lead to issues such as mold development. Honeydew is not harmless to insects; it typically attracts other pests, such as ants, that protect the honeydew producers in exchange for the sugary substance. Finally, honeydew does not increase photosynthesis in plants; instead, the sooty mold resulting from honeydew can actually reduce the plant's ability to perform photosynthesis effectively.