×Cupressocyparis leylandii is the hybrid between Cupressus macrocarpa (Monterey cypress) and Chamaecyparis nootkatensis (Nootka cypress) and has been planted widely as hedges or screen and specimen trees in Great Britain and New Zealand. It is particularly favored for seaside planting because of its resistance to salty wind. In Japan, too, this hybrid has been experimentally planted on the seacoast in Ishikawa Prefecture. Recently, it was found that cankers and heavy resin flow occurred on the stems of these planted trees. According to the observation, the symptom of heavy resin flow from the stems on the planted trees resembled to that of ‘Rooshi’ pitch canker disease. Besides this, resin flow similar to the symptom caused by Seiridium canker disease was also observed on young branches. To ascertain agents causing these cankers and heavy resin flow, field survey and fungal isolation and inoculation tests were carried out on the planted trees. All the planted trees had many resin flow on the stems and cankers on the lower parts of the tree bodies. Every diseased tree formed many necrotic lesions of different sizes in the inner bark. From the margin of each necrotic lesion in the inner bark, Seiridium unicorne fungus was dominantly isolated. This isolated fungus showed clear pathogenicity to ×C. leylandii and Chamaecyparis obtusa in the inoculation tests. These results suggests strongly that these cankers and heavy resin flow observed on the trees of ×C. leylandii is caused by Seiridium unicorne. Leyland cypress is a new record of hosts of Seiridium canker disease in Japan.
Beetles of the genus Anoplophora were collected from 14 sites in Ningxia Hui Autonomous Region, China, and were analyzed morphologically. The collections from the northern areas of the Autonomous Region were identified as Anoplophora glabripennis, while those from the southern areas as A. nobilis. But beetles collected in the central areas of the region were intermediate between the two species in the color of elytral spots, showing a geographical cline. And the male beetles with intermediate color among those, had genital organs, paramera, with intermediate shapes between two species. This fact suggests that a wide extent of introgression is going on between these two species in the central areas of Ningxia Hui Autonomous Region, China.