Scale Insects (Tended by Ants)

Ants tending scale insects. Honeydew is a sugar-rich sticky liquid, secreted by the scale insects as they feed on plant sap. Ants collect or milk honeydew directly from the scale insects, which benefit from their presence by driving away predators such as lady beetles or parasitic wasps. This way, ants are able to extract nutrients from the plants indirectly via the exudates (honeydew) of the scale insects.

The scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. They comprise the superfamily Coccoidea (about 8,000 described species of scale insects). Honeydew is particularly common as a secretion in hemipteran insects and is often the basis for trophobiosis, a symbiotic association between organisms where food is obtained or provided.