When it comes to alien invasive plants I believe Pietermaritzburg outshines every other provincial capital and can justifiably claim to have both the greatest abundance and variety in southern Africa. Although many people are well acquainted with alien invasive plants, very few think about alien and invasive animals. If you were asked to name those you know, I wonder how many species you could come up with?
We have recently spent time at a Drakensberg resort and once again encountered the now fairly well known “Harlequin ladybeetle” as it is called in a fine book by Mike Picker and Charles Graffiths titled Alien & Invasive Animals — a South African perspective, published in 2011. This beetle, belonging to the family Coccinellidae (Ladybeetles, ladybird beetles), goes by the scientific name Harmonia axyridis and is apparently of Asian origin. As these colourful beetles feed extensively on aphids, or green flies as they are commonly called, the species has been used as a biological control agent in many countries for quite a few years. Unfortunately these beetles have now invaded many countries and have themselves become a major pest.