Reproductive Behavior and Stridulatory Communication in Euscepes postfasciatus (Coleoptera: Curculionidae)

Reproductive behavior and the use of stridulatory signals are well-documented in Curculionidae. Euscepes postfasciatus is an agricultural pest of sweet potato for which effective control strategies are still lacking. In this context, the objective of the present study was to investigate the reproductive behavior and the associated acoustic and vibrational signals of this species. To analyze reproductive behavior, 100 mating pairs were observed; data were compiled in an ethogram. To study the stridulatory signals emitted in stressful and reproductive contexts, 20 and 50 pairs, respectively, were recorded using systems equipped with microphones and piezoelectric accelerometers for capturing airborne and vibratory components of stridulatory signals. Morphological analysis of the stridulatory apparatus was conducted in 30 specimens dissected and examined using scanning electron microscopy. During mating, variation was observed in the male's mounting behavior and in the female's responses. Females were found to emit a specific rejection signal, while males produced a copulatory signal, potentially to enhance female receptivity, along with a distinct behavioral display. Stress-induced signals did not differ between sexes and showed clear temporal differences with female rejection and male courtship signals. The morphology of the stridulatory apparatus conformed to the pattern described for Curculionidae, with no observed sexual dimorphism.