Like most sap-sucking insects, Gumtree Hoppers excrete excess sugars and some other nutrients in a substance called honeydew, a drop of which can be seen in the above photo. The honeydew is harvested by ants in a mutually beneficial relationship.
Classification
from Australian Faunal Directory
Order Hemiptera - bugs, hoppers and scale insects
Suborder Auchenorrhyncha - Cicadas, Hoppers, and Spittlebugs
Super-family Membracoidea - Leaf-hoppers and Tree-hoppers, 860 species in Australia
Family Cicadellidae - Leafhoppers and Gumtree hoppers, 784 named species in Australia
Subfamily Eurymelinae - Gumtree and other hoppers with gregarious nymphs and associated with ants, 202 species in Australia
Tribe Eurymelini - Gumtree hoppers, 88 species in Australia
Genus Eurymeloides
Species Eurymeloides pulchra