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A NEW BEETLE IN SA?

A new species of ladybird beetle has been recorded in South Africa, adding to the list of alien species that have entered the country. While the species is well-known as a biocontrol agent of certain aphid pests, there is also concern that it may impact on non-target species, both established biocontrol agents and possibly certain indigenous species. Current speculation suggests that the beetle arrived in South Africa on a foreign shipment of goods, although it is uncertain from where.

The species, Harmonia axyridis, has a native distribution in central and eastern Asia (including Siberia and China), has been dubbed "the Harlequin Ladybird Beetle" by local scientists. It has also established in the United Kingdom, North America and Europe.

In South Africa, the beetle was first seen in the autumn of 2004, on the Tygerhoek Experimental Farm, at Riviersonderend. It was found there again in October 2006, when its identification was confirmed. Subsequently, it has been found in the Eastern Cape (March 2007). The most recent sighting was in Cape Town in the last week of April this year. South African scientists are now starting to research the effect the beetle is having locally.

The appearance of the beetle varies greatly. Adults can be between 4.9 mm and 8.2 mm long, and 4 mm to 6.6 mm wide. The body is convex, glossy and hairless, and can range in colour from yellow to red, with between zero and 19 black spots, or black with two or four large orange or red spots.

Anyone who thinks they have seen a Harlequin Ladybird Beetle should, if possible, take a photograph and phone the Agricultural Research Council on 012 304 9560, or e-mail stalsr@arc.agric.za.

Reference: R. L. Koch. 2003. The multicolored Asian lady beetle, Harmonia axyridis: A review of its biology, uses in biological control, and non-target impacts. Journal for Insect Science 3:32.