D3010: The gut microbiota affect pair formation of dealates in the Formosan subterranean termite, Coptotermes formosanus

New colonies of Formosan subterranean termites are founded by monogamous pairs. During the swarming season, alates (winged reproductives) leave their parental colony. After swarming, they drop to the ground, shed their wings and dealated males and females form tandem running pairs that eventually mate and become king and queen of a new colony. The microbial symbionts carried by alates including the cellulose-digesting protozoa and diverse bacteria are believed critical for colony success. To test the hypothesis that gut microbiota affect pair formation, tandem running and single male and female dealates were collected from four swarm populations. Individual dealates were dissected, total protozoa and protozoa Pseudotrichonympha grassii numbers in dealate hindguts were counted and hindgut DNA was extracted for sequencing bacterial 16S rRNA genes on the Illumina platform. The effect of three factors (population origin, gender, and pairing status) on protozoa number of dealates were analyzed with ANOVA. Population origin and pairing status of dealates significantly affected total protozoa number but P. grassii numbers were only affected by gender. Total protozoa numbers were higher in tandem running than in single dealates. Males had significantly higher P. grassii numbers than females. This study showed that protozoa numbers influence whether dealates engage in tandem running, which indicates the critical role of the cellulose-digesting protozoa in pair formation. Analyses of the effects of population origin, gender, or pairing status on bacteria composition in guts of dealates are under way using the 16S metabarcoding data and the QIIME2 pipeline.