Effects of clay materials and moisture levels on habitat preference and survivorship of Formosan subterranean termite, Coptotermes formosanus

Authors: JIN, ZHENGYA - South China Agricultural University; Chen, Jian; WEN, XIUJUN - South China Agricultural University; WANG, CAI - South China Agricultural University

Submitted to: PeerJ
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/6/2020
Publication Date: 10/28/2020
Citation: Jin, Z., Chen, J., Wen, X., Wang, C. 2020. Effects of clay materials and moisture levels on habitat preference and survivorship of Formosan subterranean termite, Coptotermes formosanus. PeerJ. 8:e10243. https://doi.org/10.7717/peerj.10243.
DOI: https://doi.org/10.7717/peerj.10243

Interpretive Summary: Formosan subterranean termite is a significant pest infesting a wide variety of structures. Bait technology is an important component in termite management. The attractiveness of the bait determines its effectiveness in controlling termites. In this study, we discovered that under dry conditions, termites preferred to aggregate in wooden cylinders or baiting containers filled with bentonite. Also, termite consumed significantly more wood in the baiting containers filled with bentonite. Under wet conditions, termites preferred to aggregate in wooden cylinders filled with chlorite or attapulgite. This occurred probably because these clay material can regulate water content in the bait, and created a favorable microenvironment for termites. These clay materials can potentially be used as termite attractants in bait stations.

Technical Abstract: Formosan subterranean termite workers, Coptotermes (C.) formosanus Shiraki, often transport large amounts of clay into tree hollows and bait stations. Our previous research showed that field-collected clay samples were attractive to C. formosanus, but it was not clear whether minerals and/or moisture influenced clay attractiveness. In the present study, multiple-choice tests were conducted under dry (25%-moisture) or wet (50%-moisture) conditions to evaluate the foraging behaviors of C. formosanus responding to hollow wooden cylinders or baiting containers filled with different clay materials (bentonite, kaolin, chlorite, illite, or attapulgite), soil, or unfilled. Under dry conditions, the majority of termites were found in the wooden cylinders or baiting containers filled with bentonite. Under wet conditions, however, termites preferred to aggregate in wooden cylinders filled with chlorite or attapulgite. The percentages of termites that aggregated in baiting containers filled with chlorite, attapulgite or soil were similar, which were significantly higher than those that filled with kaolin, illite, or unfilled. No-choice tests were then conducted to study the effect of clay materials on termites. Under dry conditions, filling the baiting containers with clay significantly increased survivorship and body water percentage of termites, whereas no similar effect was detected under wet conditions. This study demonstrated that both clay type and moisture affect termites’ preference. Some clay materials can potentially be used as termite attractants in bait stations, depending on the moisture conditions.