Sugarcane Beetles

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

We are getting reports of sugarcane beetles (Euetheola humilis) showing up in large numbers in areas of North Carolina, South Carolina, and Tennessee. The adults are dark brown, about 1/2" in length, and somewhat resemble the May and June beetles you likely saw on your porch back in May-July. The sugaracane beetle has become a more significant pest of turf in recent years, particularly (but not solely) in warm-season grasses like bermudagrass. While most of you may not worry about turf (except for perhaps your own lawns), adult beetles are strongly attracted to light, which means structures near well-lit turf (schools, commercial buildings, etc.) often get hit the hardest. Sugarcane beetles may also begin invading homes and other structures as they search for a suitable overwintering site. The beetles are common insects, but their populations are usually so low that they go largely unnoticed.

One oddity about sugarcane beetles is their tendency to chew/bore into expansion joint material along the front of commercial or industrial buildings, and we've heard of some instances where they reportedly chewed through insulation, caulk, and membrane roofing material. In the case of expansion joints, the beetles may be looking for moist areas to deposit their eggs. The organic debris that can build up in expansion joints may serve as a food source for larvae.

Sugarcane beetles gathering around expansion joint (Photo: Chris Mills)

Exterior treatments will likely kill off a lot of beetles. Just make sure your customer understands that they will quite likely see other beetles which are drawn to exterior lighting (and to nearby grassy areas). Any beetles that make it inside structures should simply be removed or vacuumed up. Interior spraying isn't necessary for sugarcane beetles. Since the beetles are attracted to light, using sodium vapor lights in fixtures near buildings and mercury vapor lights for fixtures away from buildings may reduce the number of invading beetles; however, this is not always practical.