The morphology of the puparium of a species of Afrodinia near medleri Cogan, is described and illustrated using both light and scanning electron microscopy (SEM). The specimens reared from ‘gum’ in galleries of Acacia karroo Hayne (Fabaceae) in the Limpopo Province of South Africa. This represents the first description of the immature stages of an Afrotropical species of Odiniidae, the first using SEM techniques, and the first record of an association with Acacia. Biology is discussed, with the minimum period of larval development determined as 39–46 days and the puparial stage as 17–22 days. The immature stages of 12 species of Odiniidae are known and these are reviewed. The puparium of Afrodinia is most similar to that of the genus Odinia Robineau-Desvoidy, supporting the inclusion of Afrodinia in the Odiniinae. Functional morphology of the hooked spinules on the ventral creeping welts and development of subanal pads on the anal division of the larva are discussed. It is suggested that these structures aid both anchorage and mobility of larvae within the smoothly bored tunnels in which they largely reside. There is an apparent correlation between the greater size of subanal pads and a reduction in the size and extent of spinules on creeping welts.