Comparison of Temperature-Dependent Survivorship and Wood-Consumption Rate Among Two Invasive Subterranean Termite Species (Blattodea: Rhinotermitidae: Coptotermes) and Their Hybrids.

Two invasive subterranean termite species, Coptotermes formosanus Shiraki and Coptotermes gestroi Wasmann (Blattodea: Rhinotermitidae), established in South Florida have the potential to hybridize owing to their sympatric distribution, overlapping dispersal flight seasons, and interspecies mating behavior. This study examined the effects of temperature on survivorship and wood-consumption rate (WCR) to determine the potential of such hybrid termites as structural pests. Temperature tolerance was tested using groups of termites from incipient colonies established in the laboratory with four mating types (♀C. gestroi × ♂C. gestroi, ♀C. formosanus × ♂C. formosanus, ♀C. gestroi × ♂C. formosanus, ♀C. formosanus × ♂C. gestroi) in glass screw-top jars placed in incubators at 10, 15, 22, 28, and 35°C in constant darkness for 28 d. Results showed that hybrid termites have a temperature tolerance covering those of both parental species and survived at 15-35°C. WCR was not significantly different among the four mating types, but the WCR in the temperature range of 22-35°C was significantly higher than at temperatures ranging from 10 to 15°C for all mating types. Our results suggest that the potential distribution of the hybrid populations may cover most of the range of both parental species, i.e., 32.5°N and 23.5°S, and they can be as damaging as their parental species, the two most destructive termite pests, C. formosanus and C. gestroi.