Termites exhibit same-sex sexual behavior between pairs

Sexual behavior between individuals of the same sex in termites occurs actively and persistently, even in the presence of opposite-sex partners. This finding results from controlled experiments with Reticulitermes chinensis. The study rules out the classic hypothesis of a response to environmental stress or the absence of partners.

Researchers observed the formation of female-female and male-male pairs during tandem runs, a key step in couple formation. These pairs appeared more frequently than heterosexual pairs. However, the duration was shorter in same-sex pairs. Even so, the individuals maintained stable coordination and interaction over time.

Behavioral plasticity

The data indicate high behavioral plasticity. Males and females assume roles typical of the opposite sex. In male-male pairs, one individual adopts leadership behavior, common in females. In female-female pairs, one begins to act as a follower, a pattern typical of males. This reversal ensures coordination of movement and maintenance of the tandem.

Movement analysis shows synchronicity between leader and follower during movement. After accidental separation, a clear division of roles occurs. The leader stops moving. The follower initiates active searching. The pattern repeats that observed in heterosexual pairs.

The study also recorded copulation between individuals of the same sex. The behavior followed the same physical pattern observed in heterosexual pairs. The insects align their abdominal extremities and maintain contact for more than 10 seconds. The frequency of copulation in female-female pairs exceeded that of heterosexual pairs in 12-hour assessments.

Mixed groups

Another experiment evaluated mixed groups with five males and five females. Even with choice available, individuals engaged in copulation with same-sex partners. The frequency of heterosexual mating remained higher. Still, the proportion and duration of interactions between individuals of the same sex remained at significant levels.

The results indicate that the behavior is not dependent on a lack of partners. The duration of copulations did not differ between pair types. This pattern reinforces the interpretation of active, not accidental, behavior.

More information at doi.org/10.3390/insects17040400