The lepidopteran leaf-mining larvae of Holocacista capensis were recorded on the outskirts of Paarl (Western Cape), South Africa, in 2012 for the first time. Thought to have local origins, the moth has been recorded on many grape varieties in South Africa since. In order to develop appropriate management strategies, aimed at maintaining effective control of the pest in commercial vineyards, various aspects of the pests′ ecology must be known. The current study provided morphological characteristics associated with wing and abdominal colouration, which can be used to discern between male and female moths using a stereo microscope. The seasonal cycle of larvae and adults throughout a grapevine growing season was established. The leaf miner was detected in the three grape areas surveyed (Berg River, Hex River and Olifants River). Areas in the grape producing regions of the Western Cape that are heavily impacted by the leaf miner include Paarl, Riebeeck Kasteel, Tulbagh, Piketberg and Wellington. Moth and larval abundances were observed to reach considerably high numbers in February. Live larval abundances decreased from the middle of March, whilst adult abundances were only seen to drop in early April. This study aimed to assist towards the development of appropriate management strategies against the pest.