The large (up to 8cm long), rather fierce looking Emperor Moth caterpillars (Bunaea alcinoe) are back in our garden after an apparent absence of three years. I first encountered them in 2014, when several of them chomped their way through leaves of a Cussonia spicata (widely known as the Cabbage Tree/ Kiepersol). What happened to them after they had defoliated the tree is anyone’s guess for they simply disappeared after a day or two.
These caterpillars must have been feeding off other trees in our garden such as the Harpephyllum caffrum (Wild Plum), Celtis spp (White Stinkwood), and the Ekebergia capensis (Cape Ash), for my Cussonia remains untouched so far.
The picture above shows what is left of a cluster of leaves in the Cape Ash tree after the caterpillars had feasted on them. There are many of them crawling across the grass and in the compost area – I counted about twenty of them in various parts of the garden yesterday. I can only imagine that they are looking for suitable place where they can bury themselves in the ground, where they will transform into a pupa awaiting the completion of metamorphosis before emerging as a moth. Having seen several of them on the lawn, I wonder if they bury themselves under the grass too. This one is in the compost area.
The caterpillars must surely be food source for birds, although I have not seen any of them having been eaten. Three dead ones found on the lawn this morning show no signs of having been pecked at.