margarodes, otherwise known as ground pearls, are a serious insect pest in some vineyards, although they are, fortunately, found only in certain restricted regions. Margarodes weaken and kill vines with a similar action to phylloxera, and afflicted vines normally die about four years after a decline in vigour is noted.

While many species of margarodes occur on a wide range of host plants worldwide, the most damaging to vines is the Margarodes vitis of South America. There are ten species of margarodes in South Africa, five of which infest vine roots, with Margarodes prieskaensis being one of the most damaging. The pre-adult insect is a round cyst which attaches itself to the roots, and is covered by a hard, waxy covering. The insects are conspicuous by their foul odour.