Silky Hairstreak caterpillars with attendant ants.
On a broad leafed wattle these small, black caterpillars were apparently be lovingly looked after by groups of grey and black ants. The caterpillars were about 15mm long. I could not see what the ants were getting from the caterpillar but they seemed to be regularly checking the rear end.
In a local nature reserve adjoining a large national park both dominated by various eucalyptus species.
"Occurring mainly in the Dandenong Ranges where it breeds on wattles (Acacia sp.). An early spring species whose larvae feed on Blackwood (A. melanoxylon) and Silver Wattle (A. dealbata). The larvae are attended by the strong smelling ant, Anonychomyrma biconvexa. Pupation usually occurs under the bark of nearby eucalypts. " - Museum Victoria
Conservation status HIGHLY VULNERABLE