RESUMO
A new species, Pseudacanthus alani n. sp., is described from cloud forest in Oaxaca, Mexico. This species is similar to Pseudacanthus junctistriatus Kuwert 1891 in size, shape of antennal lamella, and the absence of pubescence on abdominal terga, but has larger internal tubercles, an apex of central tubercle that is not free, glabrous elytral humerus, pubescent mesepisternum and mesepimeron and mesosternal scar, and male sexual characters. Photographs are provided of the head, male and female genitalia, and plectrum. Additionally, a taxonomic key to species of Pseudacanthus Kaup 1869 is provided, complemented with photographs of diagnostic characters. Finally, we propose two junior synonyms: Pseudacanthus solidus (Arrow 1907) n. syn. of Pseudacanthus junctistriatus and Pseudacanthus truquii Kuwert 1891 n. syn. of Pseudacanthus mexicanus (Truqui 1857).
Assuntos
Besouros/anatomia & histologia , Besouros/classificação , Animais , Feminino , Florestas , Genitália/anatomia & histologia , Masculino , MéxicoRESUMO
Bess beetles are sapro-xillophagous insects that inhabit decaying logs. They display sub-social behavior and acoustic communication. Adults produce sounds with an abdomino-alary stridulatory system. The sixth abdominal tergum has lateral protuberances with spines (pars stridens), whereas the hind wings have spines in the radial cell (plectrum). The potential taxonomic utility of these spines has not been studied. We evaluated the variation of spines in the plectrum of adult females sampling four species of Proculini using traditional and geometric morphometric methods. We divided the plectrum into five zones to compare the density, size and shape of spines among zones and among species comparing each zone separately. Spine shape and size were quantified with 2D cartesian coordinates and four variables from SEM micrographs. Separate univariate and multivariate analyses of variance revealed that the size, density and shape of spines is different among zones in each of the four species. Also, spine shape and size in all zones is different among species, which would imply that plectrum spines might have taxonomic utility. Additionally, disparity analyses showed that the peripheral zones have a higher variability, and the disparity values in the middle and apex zones are higher in the two species with a wide distribution range.
Assuntos
Besouros/ultraestrutura , Asas de Animais/ultraestrutura , Animais , Feminino , México , Microscopia Eletrônica de VarreduraRESUMO
Vindex chimalapensis Ariza-Marín, Reyes-Castillo, Moctezuma & Sánchez-Huerta, a new species, is described from the cloud forest in Oaxaca, México. Vindex chimalapensis is like V. sculptilis Bates in the form of lateral elytral punctures and glabrous epipleura, but has dorsal punctures in the pronotum and the form of the aedeagus differs on the basal piece. Male genitalia, female genitalia, and head are shown in photographs. Vindex chimalapensis is the only species known from this genus with dorsal punctures on the pronotum. Ecology, distribution, and biogeography of Vindex and the Mountain Mesoamerican distribution pattern are discussed, with emphasis on V. chimalapensis.