Attributes of Yellow Traps Affecting Attraction of Diaphorina citri (Hemiptera: Liviidae)

Laboratory assays were conducted to evaluate responses of Diaphorina citri to various aspects of visual cues associated with traps in an effort to improve trap effectiveness. Addition of white or UV violet but not yellow light-emitting diodes (LEDs) increased attraction to standard yellow adhesive traps moderately (11–17%), with no difference in attraction between white or UV violet LEDs. Addition of a black border on yellow traps enhanced collections. However, there were no differences between attraction to black patterns on traps. Comparisons were made between different commercial paints, some with UV-reflecting properties or fluorescence. A yellow paint with UV reflectance, used for painting bird decoys (decoy yellow), was more attractive than the standard yellow Olson sticky trap. Addition of white or green pigment to increase intensity or enhance green reflectance, respectively, did not increase attraction. Alteration of reflectance of Olson traps with addition of UV-reflecting or fluorescent pigments did not enhance attraction of D. citri. In field comparisons, decoy yellow and fluorescent yellow sticky traps were more attractive to D. citri than Olson yellow.

Paint Relics on Middle Age Building Stones as Proxies of Commercial Routes and Artistic Exchanges: A Multi-Analytical Investigation

Fifty-four pieces out of 356 marble pieces deriving from the decorative and architectonic apparatus of the medieval monastic complex of S. Francesco of Castelletto (Genoa, Italy) preserve traces of varicolored paint layers. Microscopic samples of green, blue, red, pink, white, and yellow paint relics were collected by scalpel and analyzed by means of Scanning Electron Microscope coupled with Energy Dispersive Spectroscopy (SEM-EDS), µ-Raman, and Fourier Transform Infra-Red Spectroscopy with Attenuated Total Reflection (FTIR-ATR), to characterize pigments and binders. The combined results from the different techniques allowed verification that stone decoration in Genoa during the Middle Ages encompassed a calcite groundwork and the use of a mixture of oils and proteins (probably egg) to apply pigments. The assemblage of impurities within the pigment has been correlated with the provenance sites along the commercial continental (Hungary and France) and maritime (Sardinia, Cyprus, or Veneto) routes between the 13th and 15th centuries. Moreover, the investigation of the painted layer improved the characterization of the decorative techniques in use in Genoa during the Middle Ages.