Sugarcane Beetles

Adult sugarcane beetle (Photo: Cotinis, BugGuide.net)

We recently got a call from a NC school reporting that several buildings were being invaded by small black beetles. The insects, as it turns out, were sugarcane beetles (Euetheola humilis), a type of scarab beetle that can become a problem in the fall as it searches for a suitable place to spend the winter. The beetles are common insects, but their populations are usually so low that they go largely unnoticed. Sugarcane beetles can actually damage caulk or other sealants at expansion joints and other junctures as they attempt to dig into the area.


One thing to keep in mind about sugarcane beetles is that they are occasional pests that are normally present at relatively low levels. The beetles are attracted to light, so using sodium vapor lights in fixtures near buildings and mercury vapor lights for fixtures away from buildings can reduce the number of invading beetles; however, this may not be practical in school settings.

Sugarcane beetles gathering around expansion joint (Photo: Chris Mills, Union Co. Schools)

Insecticides are not very useful in controlling sugarcane beetles. The beetles may be sprayed directly in order to kill them, but the residual may not be sufficient to kill beetles that show up later. Any invading beetles should simply be vacuumed or swept up. In addition, replacing caulk that is damaged or missing should help decrease numbers of invading beetles.


For more information on sugarcane beetles, please see: http://msucares.com/newsletters/pests/bugwise/2009/bw0209.pdf