Reproductive Behavior and Stridulatory Communication in Sternochetus mangiferae (Coleoptera: Curculionidae: Cryptorhynchinae)

Sternochetus mangiferae (Coleoptera: Curculionidae) is an important pest of mango trees around the world. This work aimed to investigate the reproductive behavior, stridulatory communication and describe the stridulatory apparatus and basic mechanism of signal emission in this species. This knowledge may facilitate the development of monitoring and control tactics. Reproductive behavior was observed in experimental arenas where stridulatory emissions of males and females were recorded. Stridulatory signals were analyzed in two different behavioral contexts, stress and reproductive behavior. Scanning electronic microscopy and stereoscopic microscope images were analyzed to describe the stridulatory apparatus and mechanism of signal production. Reproductive behavior of S. mangiferae showed some basic behaviors, described previously in other Curculionidae, including rapid movements and encounter of pairs and mounting of females by males together with emission of stridulatory signals. In response to these stridulatory signals, females interrupted their movement which facilitated copulation. Stridulatory signals emitted in the two different behavioral contexts showed specific temporal and spectral differences and could be characterized as stress signals, male courtship signals and female rejection signals. Stress signals were emitted in higher rate than courtship or rejection signals. Stress signals were produced almost continuously while the stress factor was present. The stridulatory apparatus had a different structure of pars stridens and plectrum in males and females and an inversion of the location of these components. The basic stridulatory mechanism consisted of an antero-posterior movement of the abdomen that, when in contact with the inner surface of elytra, scraped the plectrum on the pars stridens.