To add the knowledge on the transmission and infection pattern of foliar endophytic fungi on Quercus serrata, we isolated the fungi from the different leafing stages and seasons at a naturally regenerated forest. At the first leafing season in April 2007, the leafing stage of Q. serrata was divided into 5 stages and the morphotype composition and isolation rate of endophytic fungi were examined in each stage. These data were also taken at the first, second and third leafing seasons each equivalent to April, June and August in 2008. In the first leafing season in 2007, 10 morphotypes were obtained. In 2008, 15, 11 and 13 morphotypes were isolated in the first, second and third leafing seasons, respectively. Among the obtained isolates, Discula sp. was the highest in the isolation rate and increased during the first leafing season. The isolation of Discula sp. showed lower rates at the second and third leafing seasons, while the isolation rate of Phomopsis sp. was higher than that of Discula sp. at these seasons. These results indicate that the infection of a dominant leaf endophyte, Discula sp. might occur via a spore during the first leafing season. The frequent occurrence of Phomopsis sp. may be affected by the decrease in the spore inoculum of Discula sp.
To determine the diel activity of the cerambycid beetle Monochamus urussovi in the field, number and behaviors of the adults were observed on stumps of Abies sachalinensis and Picea jezoensis at about 1-h intervals in the daytime between late July and early August in Hokkaido, Japan. The beetles began to appear in the morning and the number peaked in the afternoon of bright and slightly overcast days, indicating that they were diurnal. Sex ratio was male-biased. Most beetles rested alone or in contact with an adult of the opposite sex. The adults did not appear on rainy days. A laboratory experiment showed that there was no difference in adult behavior between photophase and scotophase at 25℃ under a photoregime of 16-h light and 8-h dark. Comparison of three Monochamus species studied so far suggested that whether a given Monochamus species was diurnal or nocturnal under the field conditions was determined not by the light conditions but by a suitable body temperature for activity.