Wingspan: male 36mm, female 42 mm
The caterpillars of this butterfly feed on a number of species of wattles, including Lightwood and Black Wattle. However we have only seen caterpillars and pupae on Black Wattle and adults on or around Black Wattle or feeding on flowers, as shown above.
Caterpillars and pupae of the Stencilled Hairstreak are protected from parasites and predators by ants, and in return supply the ants with food in the form of a solution of sugars and amino acids. The ants are essential to the survival of the caterpillars, but neither the caterpillars nor the wattles are essential to the survival of the ants, so it is just by chance that the ants will occur in the right place to allow the butterflies to breed successfully. (I infer this from a paper by Smiley and others (1988) about the closely related Imperial Hairstreak.) According to Field in "Butterflies: Identification and life history" few colonies are known to remain in Victoria. The population in Woodlands Historic Park seems to be small.
Classification
from Australian Faunal Directory
Order Lepidoptera - Moths and Butterflies, 10855 named species in Australia
Family LYCAENIDAE - Blues, Coppers and Hairstreaks, 157 species in Australia
Genus Jalmenus (11 Species in Australia)
Species Jalmenus ictinus
References
- Field, Ross P. (2013) Butterflies: Identification and life history. Museum Victoria: Melbourne.
- John T. Smiley, Peter R. Atsatt, and Naomi E. Pierce (1988) Local distribution of the lycaenid butterfly, Jalmenus eragoras, in response to host ants and plants. Oecologia 76:416-422