Abstract. Calliptamus barbarus Costa 1836 is an acridid species whose hind femora display chromatic polymorphism that may be of ruby colour with three bold and separate femoral spots, or pale orange, with only one large femoral spot. Since both bio forms (either with three (3S) or with one (1S) spot) appear to be segregated, and their sounds constitute an intra-specifi c recognition system during mating, the sounds emitted by both groups were studied in order to identify any differences between them. It was observed that the sound is produced by mandible friction in both males and females. The temporal characteristics of the acoustic emissions of the males of both bio forms showed signifi cant differences under all conditions. In females, some differences in frequency and in temporal characteristics were also detected. Likewise males, the syllable length and the number of emitted pulses are greater in the 1S than in the 3S form. Together with other differences, these observations suggest a true separation between these bio forms, with a reproductive isolation that will probably lead to a speciation process.
Résumé. Production de son chezCalliptamus barbarus Costa 1836 (Orthoptera : Acrididae : Catantopinae). Calliptamus barbarus Costa 1836 est un acridien qui présente un polymorphisme chromatique au niveau des fémurs postérieurs. Ces derniers peuvent être d'une couleur rouge rubis, avec des taches fémorales séparées et bien marquées, ou d'une couleur orange pâle, avec une seule et grande tache fémorale. Les deux formes peuvent être facilement séparées. Les sons constituant un système de reconnaissance intraspécifi que durant l'accouplement, nous avons étudié les sons produits par les deux formes pour y détecter d'éventuelles différences. Le système de production du son par friction mandibulaire, chez les mâles comme chez les femelles, a été établi. Les caractéristiques temporelles des émissions acoustiques des mâles des deux formes présentent des différences signifi catives dans toutes les situations étudiées. Certaines différences ont également été détectées chez les femelles. Pour les mâles, la durée des syllabes ainsi que le nombre des impulsions émises sont plus grands dans la forme à une tache fémorale (1S) que dans la forme à trois taches (3S). Ces faits, ajoutés à d'autres différences, suggèrent une réelle séparation, avec un isolement reproductif entre les deux formes qui pourrait conduire à un processus de spéciation.
The sounds produced by Metaleptea adspersa (Blanchard 1843) were recorded in captivity with an analogical tape recorder. The signal was digitized in the laboratory and studied with a software. Three types of sound were described: copulation, rivalry, and crepitation. All three sounds were produced only by males. The frequency of the sounds occupied a broadband, from 3-4 to 16 kHz, although the main peak frequency for each type of song differed. We also studied the structures involved in sound production. Copulation and rivalry songs were produced by the rubbing of the subcostal, radial, medial, and cubital 1 veins of the hind wing against the subcostal and radial veins of the tegmen; the enlarged cubital area of the hind wing acted as a resonator. Crepitation sound was produced by the cubital area of hind wing when its expanded membrane became taut.
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