Impact of seasonal temperatures and relative humidity on cellulose consumption by Reticulitermes flavipes and Reticulitermes virginicus (Isoptera: Rhinotermitidae)

Abstract:
The influence of seasonal ground temperature and relative humidity on cellulose consumption by two native subterranean termite species was evaluated in South Carolina, USA. Seven colonies of Reticulitermes flavipes Kollar and six colonies of R. virginicus (Banks) were studied. In-ground plastic bucket stations containing cardboard rolls were equipped with electronic data loggers to record daily temperature and relative humidity. Consumption data and number of termites in cardboard rolls were recorded every one or two weeks, depending on termite activity, and correlated with temperature and relative humidity data. Ground temperature 1 m away from bucket stations (10 cm deep) showed the highest correlation with consumption. Relative humidity recorded from all R. flavipes bucket stations was above 80%, while relative humidity in two R. virginicus bucket stations reached a low of 30% during winter months. Peak consumption and the number of termites in cardboard rolls were highest during summer and lowest during winter. Consumption patterns for both species were not statistically different. The number of R. virginicus collected was often twice as many as R. flavipes, resulting in approximately twice as much cardboard being consumed by R. virginicus. Two R. virginicus colonies were active below 40% relative humidity during cool months, while R. flavipes colonies were inactive. Predictive models of consumption as related to ground temperature and relative humidities for R. flavipes and R. virginicus.