Phytophagous insects may become serious pests of crops when introduced into a new place. Better nutritional quality and lower toxicity of new host plants and escape from natural enemies can enhance survival. The chrysanthemum lace bug, Corythucha marmorata (Hemiptera: Tingidae), is native to North America, where it exploits mainly goldenrod and its relatives (Asteraceae). It was accidentally introduced into Japan by about 2000. Since then, many reports of injury to sweet potato (Convolvulaceae) and eggplant (Solanaceae) by this species have been published. Here, we tested larval performance on goldenrod, sweet potato, eggplant, and three other known or potential host plants to investigate why the lace bug began to exploit the new host plants. Survival to adult stage was nil on eggplant, extremely low on blue daze (Convolvulaceae) and crown daisy (Asteraceae), moderate on sweet potato, and ca. 80% on goldenrod and sunflower. Developmental time was shorter and adults grew larger on goldenrod and sunflower than on the other plants. These results show that plant nutritional or toxicological qualities are not major factors that facilitate host range expansion of C. marmorata in Japan. Possible factors are discussed.
Mino-gami(Japanese kozo paper) has been utilized in various ways to conserve cultural properties for many years. Especially, usu(thin)-mino-gami is frequently used as the first back lining paper of hanging scrolls in order to support the main paper with a painting or a work of calligraphy on it. Improvement of the usu-mino-gami quality will more contribute to preservation. In the first stage of our research, the purpose is to clarify the manufacturing conditions of high-quality usu-mino-gami produced with different sheet forming techniques. As a lining paper, usability and feedback from users were considered in this study. The results showed that the sheet formation measured based on light transmission homogeneity was ranked as papermaking experts Furuta, Hasegawa and a papermaking beginner in descending order of quality. This sheet formation result agreed well with the wet tensile strength of usu-mino-gami both sensorially evaluated and measured by a tensile tester with the Finch device. The wet tensile strength decreased as the concentration of alkali solution for moistening paper samples increased. Paper prepared from fibers after net washing and from a top portion of kozo branches had a relatively low wet tensile strength. About the relationship between the order of sheet forming and wet tensile strength, the sheet formation and wet tensile strength of paper improved in the sheet forming order presumably because long fibers were filtered and formed into sheets in early sheet forming and remaining short fibers and parenchyma cells composed the paper in late sheet forming.
A holographic technique is useful for increasing the processing speed in laser grooving and scribing. In laser grooving, depth control of the processed structure is important for performing precise processing. In this paper, in-process monitoring of the depth of a structure formed by femtosecond laser processing with a line-shaped beam using sweptsource optical coherence tomography (SS-OCT) was demonstrated. In laser grooving, the structural depth and the shape were successfully monitored. The proposed method will be effective for precise laser processing with feedback control of the laser parameters based on in-process monitoring of the processed structure.
Casing treatment with an aim for the suppression of cavitation surge was experimented. For the investigation of internal flow, the observations were conducted with PIV. It was found that (a) the strength of the backflow becomes weaker than that without casing treatment, (b) unsteadiness of the backflow of inducer is remarkable.
Two-color side-view probing of light-matter interaction in the focal volume of a tightly focused fs-laser pump pulse reveals charge dynamics with 0.9 μm lateral resolution and ~45 fs temporal resolution. Use of two colors is advantageous for probing optically excited plasma regions with different density. Holographic digital focusing was were implemented to minimize the deviation of the focusing plane caused by chromatic aberrations.