Gibbaeum pubescens subsp. shandii grows in the western parts of the Little Karoo on quartzite outcrops. The little clump of dense leaves on ground level stems may become as wide as 25 cm. There is another recognised subspecies, viz. G. pubescens subsp. pubescens. "Pubescent" refers to the tiny hairs on the leaves.
Some insect has eaten holes into the leaves of the plant in picture. This happens all the time in nature. Plants sometimes develop defence mechanisms like thorns, chemical changes affecting their taste to herbivores and other devices to secure their survival. Sacrificing the occasional leaf may be a good contract to have pollinators visiting at the right time. This is not life-threatening to the plant.
People who garden or produce food have more exacting requirements for their plant environment in terms of keeping them alive than the plants themselves. This may result in the urge to ban insects from the living space of their protege plants altogether! Glass houses where the insects may not enter is a mild form of such measures. Poisons to kill all the insects within flying or crawling distance of the plants may be more effective, but unintended consequences of using poisons are being noted increasingly today. The eradication of unwanted species and thereby reducing biodiversity, usually turns out to bring unintended negative consequences (Smith, et al, 1998).