Roger Mayes 24/03/2017
Having somehow managed to get myself tagged with the label of the HO’s insect man, from time to time I get requests for assistance with identifying some of the varied and beautiful creatures which inhabit the undergrowth.
So it came about that Machiel Ellis passed on to me some photos of a species of caterpillar which one of the guides from Black Rhino Lodge said were stripping the leaves of Tamboti trees in Pilanesberg.
Doubtless feeling a bit jumpy as a result of the publicity surrounding the plague of fall army worms infesting local crops, the guide was concerned that this was some kind of alien about to wipe out one of our indigenous tree species.
Now there are some 800-odd species of butterfly in South Africa, and around 6000 moths, so if someone asks you to identify a caterpillar, sounding knowledgeable and saying it looks like a moth larva gives you about a 90% chance of being right, so that is what I did. I then passed the photos on to the ADU, who also failed to come up with an id.
But luckily Machiel was wise enough to keep one of the larvae until it metamorphosed into an adult moth, and sent a pic through to me, and thence on to the ADU, who came back immediately with an id of Achaea catella.
Google quickly turned up two interesting facts. Firstly, although an indigenous species, it is indeed related to the fall army worm, as well as to the cutworms which drive local gardeners to distraction. And secondly, a few weeks prior to the infestation in Pilanesberg, the Kruger Park had experienced a similar outbreak, from which the Tamboties had already started to recover.
Read the Kruger Park article.
In short, an interesting act of nature, but nothing to get too worried about.