Aim Based on seven consecutive seasons of biotic survey and inventory of the terrestrial and freshwater plants and animals of the 30 major islands of the Kuril Archipelago, a description of the biodiversity and an analysis of the biogeography of this previously little known part of the world are provided.Location The Kuril Archipelago, a natural laboratory for investigations into the origin, subsequent evolution, and long-term maintenance of insular populations, forms the eastern boundary of the Okhotsk Sea, extending 1200 km between Hokkaido, Japan, and the Kamchatka Peninsula of Russia. A chain of more than 56 islands, the system is only slightly smaller than the Hawaiian Islands, covering an area of 15,600 km 2 and providing 2409 km of coastline.Methods Collections of whole specimens of plants and animals, as well as tissue samples for future molecular studies, were made by teams of scientists from Russia, Japan, and the USA, averaging 34 people for each of the seven annual summer expeditions (1994)(1995)(1996)(1997)(1998)(1999)(2000). Floral and faunal similarities between islands were evaluated by using Sorensen's coefficient of similarity. The similarity matrix resulting from pair-wise calculations was then subjected to UPGMA cluster analysis.

Female parents of Elasrnucha dorsalis attend their offspring and show specific sequential defensive behavior when disturbed. Intense responses of brooding females such as wing fanning were usually triggered by exposure to crushed nymphs. Maternal care continued for a long time, sometimes into the fourth or last nymphal instar.Female removal experiments showed that maternal defense is highly effective under field conditions. High egg mortality observed in the field was probably due to the predation by an ant, Myrmica ruginodis, which occurred at high densities on the host plant, Aruncus dioicus. Most of the egg masses were found on the leaves subtending axillary inflorescence of the female plants, and nymphs usually aggregated and fed on fruits in the inflorescence. Because the food of nymphs is temporally limited, the female can produce only a single brood. Thus, temporality of food resources as well as a heavy predation pressure may have led to prolonged maternal care.

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