Brevipalpus californicus (Banks) was infected with 'Candidatus Cardinium' bacteria (Cardinium). Tetracycline-treated females produced many male progeny even though untreated females produced only female progeny. B. californicus appears to be feminized by Cardinium. The values for net reproduction rate (R0), generation time (T) and intrinsic rate of natural increase (r(m)) calculated for B. californicus were 7.48/day, 31.45 days and 0.064/day, respectively. The comparison of infected females with uninfected males and other closely related species, indicated that Cardinium does not have a negative effect on the fitness of B. californicus.

In this study, we aimed to examine physical competence in the lower grades of elementary school by applying three teaching strategies: ingenuity of teaching materials, relationship with rich friends, and the teacher s approach to enhance physical competence. Physical competence was composed of three factors: perceived physical competence, feelings of control, and peer and teacher acceptance.In addition, we examined the relationship between physical competence and tactical decision-making ability. We hypothesized that improving tactical decision-making ability would enhance students perceived physical competence and feelings of control.Eighty-two first-grade students participated in this study. The students were divided into three groups and were required to play tag games. To evaluate the physical competence of students, weutilized the Okazawa, Kita and Suwa s physical competence scale developed in 1996. We then divided the participants into upper and lower groups according to their physical competence or factor score. To analyze students decision-making ability, we made them play the same games for one hour before and after the unit. We video recorded the games and used the Game Performance Assessment Instrument (GPAI) for data analysis. We reported three main findings. First, when teaching strategies were applied to enhance physical competence, the upper group maintained a high value both before and after the unit, while the lower group improved after the unit. Second, decision-making ability regarding game performance improved in both the upper and lower groups. Third, improving decision making ability is necessary to enhance physical competence in the upper group. Finally, there was a negative relationship between ball-keeping (or waiting until the game situation changes) and perceived physical competence in the upper group, and between ball-keeping and feelings of control in both the upper and lower groups.Our study demonstrated that students physical competence improved when teaching strategies were applied to enhance physical competence. Additionally, we showed that improving students decision-making ability is critical to increasing their physical competence in the upper group.