Pest of the month: Citrus Longicorn

Last month in Osaka, I became a fan of yakitori food. One of my visits to a yakitori restaurant was rewarded with an unexpected find. As I was entering the restaurant with my friends, I saw a perfect specimen of a longicorn beetle (image above left). Back in Sydney, I identified the specimen as Citrus Longicorn (Anoplophora chinensis) also known in Japan as gomadara-kamikiri.

What is the connection to bonsai? Just a couple of things. This beetle is a serious pest of many woody plants and it has been repeatedly found in bonsai trees imported to the United States from China and Korea. Apparently, it has also been introduced to the UK. The larva of this beetle (image above right) is a timber borer and its host plants include some of the most popular species used for bonsai. They include maples, elms, Citrus species, kumquat, Casuarina, Hibiscus, willows, pear, plum, apple, plane trees, Cotoneaster, birches, beech, poplars, Japanese Red Cedar, crepe myrtle, Ficus species and many others. If your bonsai tree is infested with a single larva of this beetle you are likely to loose a significant amount of wood in the trunk. To get rid of it you have to open one of the tunnels in the trunk and inject pest oil into it to kill the larva. So far, Citrus Longicorn hasn’t been introduced to Australia.