Rivalry between Stink Bug Females in a Vibrational Communication Network.

In the field, male pheromone attracts stink bugs to meet on the same plant and triggers females to call a male by the emission of the calling song. As first among Pentatomidae we describe female rivalry in Chinavia impicticornis, C. ubica and Euschistus heros. Rivalry starts in C. impicticornis by synchronized exchange of the first type of the female calling song pulse trains and proceeds by one of them either to change pulse trains from the first to the second type or to produce readily repeated single pulses. Both reactions either inhibit calling of the rival female or trigger her to respond by alternation with the second type of the calling song pulse trains. Female rivalry in C. ubica differs by the emission of the rival song that replaces alternation with the second type of the calling song typical for C. impicticornis. E. heros females synchronize pulses of the calling song duets and induce emission of the female rival song by one of them that partly inhibits singing of the other. These competitive interactions in Chinavia species reduce the proportion of couples when compared with single couples on a plant. Contrary to both Chinavia species, E. heros female rivalry does not inhibit male response, male signals overlap female emissions and create complex vibrations with modified amplitude modulation pattern caused by interference.