title: Relative humidity preference and survival of starved Formosan subterranean termites (Isoptera: Rhinotermitidae) at various temperature and relative humidity conditions.
abstract: Foraging groups of Formosan subterranean termites, Coptotermes formosanus Shiraki were tested for their relative humidity (RH) preference in a humidity gradient arena in the laboratory at a constant temperature of 26°C. Five RH levels (9%, 33%, 53%, 75%, and 98%) were maintained in the test arena comprising of a series of closed containers by using dry silica gel, saturated salt solutions, or distilled water alone. Termites gradually aggregated to the highest RH chamber in the arena. After 1 h, a significantly greater percentage of termites (≈46%) aggregated to the highest RH chamber (98%) than to the lower RH chambers (≤75%). After 12 h, > 97% of the termites aggregated to the 98% RH chamber. In survival tests, where termites were exposed to 15 combinatorial treatments of five RH levels (9%, 33%, 53%, 75%, and 98%) and three temperatures (20°C, 28°C, and 36°C) for a week, the survival was significantly influenced by RH, temperature, and their interaction. A significantly higher mortality was observed on termites exposed to ≤75% RH chambers than to 98% RH chamber at the three temperatures and significantly lower survival was found at 36°C than at 28°C or 20°C. The combination of temperature and RH plays an important role in the survival of C. formosanus.
authors.affiliation: Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA.
authors.forename: Bal K
authors.initials: BK
authors.lastname: Gautam
authors.forename: Gregg
authors.initials: G
authors.lastname: Henderson
mesh_terms: D000818:Animals; D006813:Humidity; D020049:Isoptera / Q000502:physiology*; D013217:Starvation; D016019:Survival Analysis; D013696:Temperature