Abstract
Eight katydid species of the leaf-mimicking specialist genus Typophyllum were found in the southeast of Ecuador in an area comprising part of the eastern Andean cordillera and foothills toward the Cordillera del Cóndor in elevations between 850 and 3000 m. They are described along with the peculiar calling songs and other interesting aspects of their biology. Three of these species are new: T. morrisi sp. nov., T. onkiosternum sp. nov. and T. vignoni sp. nov. A fourth species represented by a single male is possibly new as well. In males and females of a species considered as identical with T. egregium Hebard 1924, which was previously known from a unique female specimen, was found a remarkable variation of coloration, in addition to the striking sexual dimorphism typical for the genus, with the females being twice as large as the small males. The latter is related to the curious mating behaviour, which is documented for this species and T. erosifolium Walker 1870. The two other species found in the region are T. bolivari Vignon 1925 and T. mortuifolium Walker 1870. The calling songs of four species were recorded. In T. erosifolium and T. morrisi sp. nov. the sounds are almost pure sine waves at the lower boundary of ultrasound. In T. egregium and T. onkiosternum sp. nov. the spectrum of the carrier frequency is broader, which might be related to lower and denser vegetation at higher elevation. Based on the intraspecific variety found in T. egregium and T. erosifolium, which includes variation in tegmina shape and venation pattern, are established several syonymies among Typophyllum species from western South America. T. erosifolium is found to be identical with T. peruvianum Pictet 1888 syn. nov. Additionally are considered identical T. inflatum Vignon 1925 and T. gibbosusm Vignon 1925 syn. nov., T. trigonum Vignon 1925 and T. quadriincisum Vignon 1925 syn. nov., and finally T. lacinipenne Enderlein 1917 and T. acutum Vignon 1925 syn. nov. and T. undulatum Caudell 1918 syn. nov. The discussion treats the problematic taxonomy of the little walking leaves, bioacoustics, the pre-copulatory riding behaviour, the sophisticated mimesis, and very briefly the uncertain position within the katydid phylogeny.