The blueberry bud mite Acalitus vaccinii (Acari: Eriophyidae) was discovered in Mpumalanga, which is the first time it has been found in South Africa. This mite is an economically important pest of cultivated and wild blueberries, and was known only from North America until now.

Effect on yield

It lives in the flower buds of its host plants, and the infested buds develop into typical reddish rosette-like galls. This damage reduces flower and berry formation, and may reduce yields drastically. Infestation levels found in South Africa so far have been high, with flower and berry formation being reduced by up to 90%. These mites are microscopic in size, and associating them with unknown symptoms and identifying them is notoriously difficult.

Charnie Craemer, an Agricultural Research Council (ARC) mite taxonomist with expert knowledge on these tiny plant-feeding mite pests, recognised the species as the cause of the damage symptoms, and identified it as the blueberry bud mite. Knowing the identity of a pest, enables one to locate all the available information on it and facilitates investigation and the use of appropriate control strategies. Future actions can now be planned in an attempt to reduce the economic impact of this mite on the blueberry industry.

Presence in other areas

This pest has not yet been found in the Western Cape, the main area of blueberry cultivation. The dissemination of information about the mite to blueberry farmers and organisations, will equip producers with the necessary knowledge to detect the presence of the bud mite early and prevent local build-up and spread of infestations that will result in increased damage and economic losses. – ARC Plant Protection Newsletter

For more information contact Charnie Craemer at