Honeydew is a sweet, sticky substance produced by certain insects, particularly aphids and scale insects. These insects feed on plant sap and excrete the excess as honeydew, which can attract other insects like ants. Honeydew can also promote the growth of sooty mold, a black fungus that can cover leaves and reduce photosynthesis. In addition to its insect-related origins, honeydew is also the name of a type of melon, known as honeydew melon. This fruit has a smooth, pale green skin and sweet, juicy flesh. It is often enjoyed fresh in fruit salads or as a healthy snack.