By Dr. Blake Wilson, LSU AgCenter Entomologist
This week I received a call from independent crop consultant, Randy Richard, who reported seeing sugarcane stalks infested with termites. When Randy and I returned to the field in St. John the Baptist Parish, we found about two dozen sugarcane stalks which were entirely hollowed-out and contained hundreds of active termites. The damage to the stalks had occurred so rapidly, the tops of the plants were still green. Although some plant stress was apparent externally, symptoms were not as severe you would expect from seeing the inside of the infested stalks. Inspection of other areas in the field revealed the infestation was not widespread and appeared to be limited to a single corner of the field. Specimens were collected and identified by LSU AgCenter insect taxonomists as the Formosan subterranean termite, Coptotermes formosanus, the same pest wreaking havoc to homes and other buildings in New Orleans.
Although, the Formosan termite is an invasive species, its presence in Louisiana is not a new finding. The pest has been established throughout most of the state since the 1960s, and has since spread across the southeastern US. Incidents of termites attacking Louisiana sugarcane have been reported in the past, but situation is rare and previous infestations were determined to be our native species, Reticulitermes flavipes. The Formosan subterranean termite has been reported attacking sugarcane in China, Hawaii, and other regions, but this is thought to be the first record of the species infesting cane in Louisiana. Termites of various species are known to attack sugarcane throughout the tropics, and in some areas termites are the primary insect pests of cane. With the termite swarms in early summer reaching immense numbers in the greater New Orleans area, it is a bit surprising sugarcane hasn’t come under attack more often. One explanation is that some of the production practices make it difficult for termite colonies to establish in sugarcane fields. Lighting may also be a factor. The field where this infestation was found is adjacent to a major highway with large street lights less than 50-ft from field edges. The reasons why termites aren’t common pests of sugarcane here are not well understood, but we are grateful none-the-less.
While the photos included here are a bit alarming, I don’t think there is cause for panic. This appears to be an isolated incident. Formosan termites have had plenty of opportunity to become widespread pests of Louisiana sugarcane, but that isn’t the situation. Still, it is worth keeping an eye on. We will continue to monitor the infestation to see how it develops