Abstract
We have in Japan two species belonging to the genus Ladoga: camilla and glorifica. The former is widely distributed over Japan from Hokkaido southwards to Kyushu, while the latter is strictly endemic to Honshu and absent from abroad. They are usually sympatric in Honshu. In this paper, the zoo-geographical characters are analyzed from an ecological standpoint, especially from their larval foodplants. Both field surveys and experimental studies disclosed that the larval food-plants of L. camilla have wide spectrum to all subgenera and sections of the genus Lonicera and Weigela (Caprifoliaceae). On the contrary, those of L. glorifica are restricted only to a certain number of species of Lonicera. L. camilla prefers the forest margine of the cold temperate zone of Eurasia, where the larval food-plants belonging to Sect. Coeloxylosteum of the genus Lonicera grows abundantly. In Japan, the warm temperate zone is also attractive to Weigela, which may cause the southward extension of the range of L. camilla. On the other hand, the main haunt of L. glorifica is the light shrubland of comparatively dry regions in the warm temperate zone, where the main food-plant of L. glorifica. Lonicera japonica covers the crown of the shrubs. The northernmost ranges of both L. glorifica and Lonicera japonica are almst the same. The zoo-geographical relations between L. camilla and L. glorifica in Japan bears a close resemblance to those between L. camilla and L. reducta in Europe. The records of the larval food-plants of Japanese Ladoga hitherto known are also reviewed with some comments.
