First records of two invasive species of thrips （Insecta： Thysanoptera） from Kyoto and Wakayama Prefectures

Two invasive species of thrips were recorded from Kyoto and Wakayama Prefectures. Adults and larvae of Haplothrips nigricornis were collected on flower heads of Tagetes patula at the University Farm, Kyoto Prefectural University in Shimogamo, Kyoto City and on those of Senecio madagascariensis in Gobo City, Wakayama Prefecture. Some adults of Tenothrips frici were captured on flower heads of Hypochaeris radicata on roadsides in Minamiyamashiro-mura, Kyoto, and in Wakayama City, Wakayama. We noted T. frici found in Sapporo City, Hokkaido, as the most northern locality in Japan

Molecular Phylogenetic Analysis of Japanese Soil-dwelling Mundochthonius Pseudoscorpions (Pseudoscorpiones: Chthoniidae)

Poster Presentation

Effect of clenching on biomechanical response of human mandible and temporomandibular joint to traumatic force analyzed by finite element method

Purpose: The purpose of the present study was to analyze the effect of clenching on the biomechanical response of human mandible and temporomandibular joint (TMJ) to traumatic force by the finite element (FE) method. Material and Methods: FE models of the mandible and the TMJ in resting and clenching positions were prepared. Distribution and magnitude of von Mises stress were analyzed by applying force as a point load in the symphyseal, canine, body and angle regions of the mandible. In addition, strain energy density (SED) at the articular disc and in posterior connective tissue of TMJ was analyzed. Results: In the resting position, von Mises stress was mainly concentrated at the condylar neck and in the retromolar region of the mandible. In the clenching position, the stress at the condylar neck decreased in all loadings. The stress in the retromolar region similary decreased in the symphyseal, canine and body loading, respectively; however, higher stress was observed in the retromolar region on the loading side in the angle loading. High SED was generated at the articular disc and in posterior connective tissues of TMJ in the resting position. The SED in these tissues decreased in all loadings in the clenching position. Conclusions: Clenching generally reduces stress at the condylar neck and in the retromolar region of the mandible, and strain energy at the articular disc and in posterior connective tissue of TMJ by traumatic forces on the mandible; however, clenching induces greater stress in the retromolar region on the loading side by traumatic force to the angle region

First instar nymphs of two peltoperlid stoneflies (Insecta, Plecoptera, Peltoperlidae)

The first instar nymphs of two peltoperlid stoneflies, i.e., Microperla brevicauda Kawai, 1958 of Microperlinae and Yoraperla uenoi (Kohno, 1946) of Peltoperlinae, were examined and described. Additionally, the phylogeny and groundplan of the first instar nymphs of Peltoperlidae and Plecoptera were considered. The first instar nymphs of M. brevicauda have a slender body with a prognathous head of typical shape; they represent a groundplan in Plecoptera. On the other hand, the first instar nymphs of Y. uenoi have a broad, cockroach-like body with an orthognathous and shortened head, the latter being regarded as a potential autapomorphy of Peltoperlinae. Such differences in body shape between the subfamilies are speculated to arise from heterochrony. The three-segmented cerci of Y. uenoi are characteristic to Systellognatha, whereas the four-segmented cerci of M. brevicauda were independently acquired within Microperlinae. The structure and distribution pattern of chloride cells in the first instar nymphs of Plecoptera were also discussed. The presence of coniform chloride cells is a potential groundplan of Arctoperlaria. One to two pairs of chloride cells are distributed on the first nine abdominal segments of M. brevicauda; this represents a groundplan character of Systellognatha. On the other hand, one to four pairs of chloride cells are found on the second to ninth abdominal segments of Y. uenoi; this distribution pattern may be an apomorphic groundplan of Peltoperlinae