Prior Opposite-Sex Cohabitation Is Associated with Allogrooming Behavior and Oxidative Physiology in Dealates from a Single Colony of Reticulitermes chinensis

Pair formation in termites involves prolonged contact, but associations of brief opposite-sex cohabitation with allogrooming and oxidative physiology remain unclear. We randomly assigned virgin Reticulitermes chinensis dealates from one field colony to opposite-sex or same-sex dyads for 60 h. Directed allogrooming was recorded for 1 h in triads containing a focal individual and two opposite-sex candidates, one from each treatment. Survival was monitored for 44 d; separate individuals were sampled immediately after cohabitation for assays of oxidative markers and antioxidant enzymes. Opposite-sex-cohabited males groomed focal females longer and more frequently in all six female-focal triads, but neither comparison remained significant after a four-test Holm correction (both p = 0.125). No comparable female-actor pattern or focal-to-candidate grooming bias was detected. The malondialdehyde and protein carbonyl concentrations were lower after opposite-sex cohabitation; 8-hydroxy-2′-deoxyguanosine was lower only in females. Neither the assay-reported reactive oxygen species values nor the survival differed detectably. Preliminary enzyme findings indicated higher male, but lower female, catalase activity, and lower superoxide dismutase activity in both sexes without a detectable sex × cohabitation interaction. These observations identify an exploratory male grooming pattern and marker-specific physiological differences at the treatment end. Copulation was unverified, and fixed source-dish and marking-color assignments limit attribution to cohabitation alone.