Hi SWishart, nice photo. Dolichoderus scabridus is very similar to Dolichoderus doriae, but you can tell them apart by the spines on the shoulders of Dolichoderus doriae. Typically, Dolichoderus doriae tends to be in the wetter areas, such as Namadgi, while Dolichoderus scabridus is dominant in the dryer areas. Cheers, Jon