This Casuarina was infested with numerous clumps of frass held loosely by silky threads. This is the entrance to a hole made by a swiftmoth caterpillar. Several contained a curious clump of leaves (needles) and demanded further investigation. These seem to be a food source for the caterpillar to continue eating while hiding in its retreat over the daylight hours.
Thank you super sleuth Leuba for your ID of this moth. http://www.projectnoah.org/spottings/170... There seems to be no images easily available online for this cryptic caterpillar so this may be some compensation for its invasion of privacy (and probably) its life for my curiosity. http://gvcocks.homeip.net/lepidoptera/xy... I was accompanied by Angy Bee, Leuba and Pamsai, and this bush walk was particularly enjoyable.