In November 2003, diseased leaves with lesions characterized were found on ginkgo (Ginkgo biloba L.) planted on the roadside in Setagaya, Tokyo, Japan. These lesions were brown spots with yellowish margin, and salmon pinkish acervuli and black perithecia were formed on their surface. Conidia are aseptate, hyaline, cylindrical, obtuse at both ends, and measured 17.9～20.4×5.1～7.7 µm (av. 18.4×6.9 µm). Appressoria are clavate or slightly irregular and brown colored, 8.9×9.6 µm. Perithecia are globoid and elliptic, black, 114〜178 µm in diameter. Asci are 8 spored in two rows, hyaline, clavate, 33.2〜63.8×5.1〜10.2 µm (av. 43.5×7.8 µm). Ascospores are hyaline, aseptate, cylindrical to fusiform, 12.8〜17.9×5.1〜7.7 µm (av. 17.1 ×6.4 µm). The pathogenicity was confirmed by the inoculation test. The causal fungus was identified as Glomerella cingulata (Stoneman) Spaulding & Schrank (=Colletotrichum gloeosporioides (Penz.) Penz. and Sacc). Anthracnose of ginkgo was proposed as a new disease in Japan.
To determine how forest wildlife use tree cavities, we investigated seasonal changes in species which used tree cavities and the numbers of tree hollows used in the daytime and nighttime over a year in Obihiro City, Hokkaido, Japan. We found 3 species of woodpeckers, which are primary producers of tree cavities, and 12 species of other birds and mammals, which are secondary users of the cavities. The tree cavities were used both daytime and nighttime throughout most of the year. The highest rates of use were recorded in June in daytime and July at nighttime. Although seasonal trends were apparent, the rates of use were almost the same between daytime and nighttime in each season. Although the rates of use by secondary user birds were higher in the summer breeding season, the great spotted woodpecker, lesser spotted woodpecker, Eurasian nuthatch, and Russian flying squirrel used cavities throughout the year. Other species were also observed using the cavities for roosting or resting. Thus, different wildlife use tree cavities in various ways.