This post supplements my previous post, about a trip to Ollera Creek.
A nest but not the right nest
While we were sitting in the shade enjoying a snack, we were visited by a number of small yellow and brown wasps which I immediately identified as Yellow Paper Wasps, Ropalidia romandi, and warned people about: they sting when threatened. Fortunately we were all mature enough not to react thoughtlessly when the wasps landed on exposed skin, apparently in search of moisture, and no-one was hurt; but we did look for their nest.
This, high in a nearby tree, was the best candidate but a closer look with the telephoto lens showed that it was a green-ant nest; see this post for the wasps and the similarities and differences of their nests.
Not a nest at all
At our next stop we noticed this large untidy bundle hanging on a vine:
I suggested, tongue in cheek, that it might be the nest of a Giant Sunbird. The resemblance was close enough to tempt momentary belief, but the reality was mundane: the vine had died, and all its branches and leaves had simply slipped down its main stem to form the bundle. It may have been a Matchbox Bean vine, as they were common in the area beside the creek, but I’m not sure.
Probably not a nest
This is still a mystery.
A small tree near the beach was affected (infested?) by these strange growths. They ranged from fist-size clumps down to straggles of thready growth, and seemed to be growing directly out of the branches. They were almost the same colour as the foliage but some of them had dead-looking brown areas.
As this site says, “Galls are growths on plants which can be caused by parasitic fungi, bacteria, nematode worms, gall insects, or mites. The trick is done by the plant itself, which makes abnormal growth in response to a chemical irritant produced by the parasite.”
That, very roughly, is what we seem to be seeing here, but we don’t know the cause. If the parasite was an insect, the growth would count as a nest; if not, not. Gall wasps usually form woody lumps, like this or this, rather than the finely divided branching structure we found, so I suspect it’s not a nest.
The tree was tentatively identified as a Beach Cherry (Exocarpos latifolius). If that’s what it is, it’s a member of the Sandalwood family and there’s a sort of poetic justice in the infestation, since the tree itself is parasitic on the roots of other trees.