Detection and Control of Subterranean Termites Using In-Ground Termite Monitoring Stations and Chitin Synthesis Inhibitor Baiting for Singapore Urban Trees

Abstract Background This study demonstrated the potential of in-ground (IG) termite monitoring stations coupled with chitin synthesis inhibitor (CSI) baiting as a complementary solution to visual inspection for tree termite detection and control in Singapore. Methods Using lure wood pieces collected from activated IG stations to serve as a basis for comparison, we evaluated the destructiveness of detected termite species and reported their unique feeding patterns. Chitin synthesis inhibitor (CSI) baiting with chlorfluazuron was used for termite control. Results A total of 6 termite species were detected: Coptotermes gestroi (Wasmann), Coptotermes curvignathus (Holmgren), Schedorhinotermes medioobscurus (Holmgren), Macrotermes gilvus (Hagen), Macrotermes carbonarius (Hagen), and Microcerotermes crassus (Snyder). However, the detection capability varied depending on site conditions such as intermittent flooding events, high soil salinity, and reduced foraging behavior after nesting within or near a host tree. This behavior of reduced foraging, in part, could be affected when heavily infested trees are removed, forcing termites to migrate and search for new food sources, leading to activation of nearby IG stations. In terms of termite control, CSI baiting with chlorfluazuron could effectively eliminate termite colonies for 3 species: C . gestroi , C . curvignathus , and S . medioobscurus . Colony elimination time ranged from 3 to 6 weeks and 24 weeks, respectively. Conclusion Considering the effectiveness of IG stations coupled with CSI bait in detection and control of subterranean termite species, large-scale application of this system in an urban tree context is discussed.