Temporal variations in symbiotic hindgut protist community of the subterranean termite Reticulitermes lucifugus Rossi in Sicily.

The dynamics of symbiotic protist communitiesof Reticulitermes lucifugus ‘‘Sicily’’ were investigated toassess the effects of seasonal environmental conditions andthe termite’s feeding activity. In worker and soldier castes,the total protist population (total abundance), individualspecies abundances, and species proportions in their hindgutswere examined monthly from December 2012 toFebruary 2014. The main protist species taken into accountwere Dinenympha fimbriata Kirby, D. gracilis Leidy, Pyrsonymphaflagellata Gras., Spirotrichonympha flagellataGrassi u. Fo` a, Holomastigotes elongatum Grassi u. Fo`a, andTrichonympha agilis Leidy, while others were not specificallyidentified, but were counted together. Seasonalcomparisons between worker and soldier castes were made.Further, monthly data of workers were examined. Wealways found the presence of symbiontic protists in workerand soldier hindguts, therefore we hypothesize that termitesfed without periods of interruption. In both castes the totalprotist population and species abundance showed variabletrends with the highest values in summer. Workers werefound to have significantly larger populations of protists andabundances of individual species than soldiers. Similarprotist species were observed in both castes and in allperiods, except for H. elongatum which was sometimesabsent in soldiers. In hindguts of workers and soldiers the proportions of the protist species often showed a significantvariation across seasons except for S. flagellata and T.agilis. In both castes we always detected the highest percentageof Dinenympha spp. with respect to the otherspecies. Elements that might influence these aspects arediscussed.