7 research outputs found
Landmark Data to Distinguish and Identify Morphologically Close Tabanus spp. (Diptera: Tabanidae)
Tabanus spp., also known as horse flies (Diptera: Tabanidae), are important vectors of several animal pathogens. Adult females of Tabanus megalops and Tabanus striatus, which are members of the T. striatus complex, are morphologically similar and hence difficult to distinguish using morphological characteristics. In addition, molecular identification by DNA barcoding is also unable to distinguish these species. These two species can occur sympatrically with Tabanus rubidus, which is morphologically similar to T. megalops and T. striatus. Wing geometric morphometrics has been widely used in various insects to distinguish morphologically similar species. This study explored the effectiveness of landmark-based geometrics at distinguishing and identifying T. megalops, T. rubidus, and T. striatus in Thailand. Specimens were collected from different geographical regions of Thailand, and only unambiguously identified specimens were used for geometric morphometric analyses. Left wings of females of T. megalops (n = 160), T. rubidus (n = 165), and T. striatus (n = 85) were photographed, and 22 wing landmarks were used for the analysis. Wing shape was able to distinguish among species with high accuracy scores, ranging from 94.38% to 99.39%. We showed that morphologically very close species of Tabanus can be reliably distinguished by the geometry of their wing venation, and we showed how our experimental material could be used as a reference to tentatively identify new field collected specimens
Influence of temperature and dopant concentration on structural, morphological and optical properties of nanometric Ce 1−x Er x O 2−δ ( x = 0.05–0.20) as a pigment
Ceramic pigments based on cerium oxide were synthesized by self-propagating room temperature method and their color properties were assessed from the viewpoint of potential environmentally nontoxic pink pigments. Thermal stabilities of the pigments were examined at 600, 900 and 1200 degrees C. According to X-ray powder diffraction and Raman spectroscopy results, all obtained pigments were singlephase solid solutions of cerium oxide, independent of the concentration of dopants. The X-ray analysis showed that the crystallites were of nanometric dimensions, as recorded and by transmission electron microscopy analysis. Color characteristics of solid solutions, which depended on concentration erbium ions and calcination temperature, and their position in the chromaticity diagram were studied by ultraviolet visible spectrophotometry, which confirmed potential application of environmentally friendly pigments of desired color. The color efficiency of pigments was also evaluated by calorimetric analysis.Accepted version: [http://cer.ihtm.bg.ac.rs/handle/123456789/3174