EVALUATION of the LOUISIANA STATE PROGRAM to TREAT TREES INFESTED with FORMOSAN SUBTERRANEAN TERMITES (ISOPTERA: RHINOTERMITIDAE) in LOUISIANA

Abstract:
The Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), is currently considered the most destructive insect in Louisiana. It attacks living trees eating the centers and constructing a carton nest within. Infested trees can serve as reservoirs for termites to infest structures. In an effort to reduce termite densities, public trees in the Greater New Orleans and Greater Lake Charles area were drilled by licensed pest management professionals and injected with insecticide foam. Evaluation on these treatments was carried out by the Louisiana State University (LSU) Agricultural Center on 168 heavily termite-infested trees. Evaluation trees were selected and inspected by LSU Agricultural Center personnel for termites before treatment. Treatments included fipronil (Termidor®), imidacloprid (Premise®), and control trees (treated with water). Trees were inspected for termites 1, 6, 12, and 18 months after treatment. Insecticide treatments significantly reduced the percentage of trees infested with Formosan and native subterranean termites compared to pretreatment percentages (100 %). The percentage of trees infested with Formosan subterranean termites observed in water treatments was not significantly different after treatment compared to pretreatment percentages (100 %). The lowest percentage of trees infested with Formosan subterranean termites at 18 months after treatment was observed in fipronil treatments. The percentage of infested trees decreased with time for fipronil treatments only. Significant differences in the percentage of trees infested with native subterranean termites were not observed among insecticide treatments.