CHAPTER 3

SECTION 2. Superorder ORTHOPTEROIDEA

TERRESTRIAL ORTHOPTEROID INSECTS

Judging from the literature, Japanese entomologists have practically not studied the orthopteroid insects on the Kuril Range. G. Ya. Bei-Bienko (1949), in the first article devoted to the dermapterans and the orthopterans of the Sakhalin and the Kuril Islands, cites 11 species for the Kurils, based on the collections of N. N. Konakov and other zoologists. Later, in an analysis of the orthopteran and dermapteran insects of mixed and broad-leaved forests of the Far East (Bei-Bienko, 1953), he again touches on the island fauna.

The collections we have made have doubled the number of known species of the orthopteroid insects living on the archipelago, increasing it to 22. The materials collected have been analyzed and published by G. Ya. Bei-Bienko (1966). In his opinion, the species composition of the terrestrial orthopteroid insects of the Kuril archipelago may be considered elucidated, in the main, although the finding of some additional species on Iturup, Shikotan, and other islands is possible. In fact, in a later work of S. Kuwayama (Kuwayama, 1967), another 3 species of locusts (Chorthippus brunneus Thnb., Mongolotettix japonicus Bol., Podisma (Podisma) aberrans Ikonn.¹) and one long-horned grasshopper (Gampsocleis ussuriensis Adel.), collected by Japanese investigators on Kunashir and Iturup in the 1940s, were added to the list of species published by G. Ya. Bei-Bienko (1966).
¹ Podisma aberrans Ikonn. is insufficiently studied; it has been described on the basis of 1 female from Primorskiy Kray; it is also known from Northeast China (Bei-Bienko, Mishchenko, 1951). It is very close to P. kurilensis B.-Bien., and that it is a synonym of it cannot be excluded.

In all, 26 species of orthopteroid insects, belonging to three orders, are known on the Kurils at the present time: the cockroaches (Blattoptera), 1 species; the dermapterans (Dermaptera), 2 species; and the orthopterans (Orthoptera), 23 species, including the long-horned grasshoppers (Tettigonioidea), 5; the crickets (Grylloidea), 4; and the locusts (Acridoidea), 14.

The distribution of these insects within the limits of the Kuril Range is limited to the southern islands, Kunashir, Shikotan, and Iturup. Further north, despite careful searches, not a single species has been found thus far, although the presence of individual representatives of the group on Urup is possible. The distribution of the orthopteroid insect fauna on the enumerated islands is uneven. All the species are represented on Kunashir (23), significantly fewer on Shikotan (5) and Iturup (6). But even on Kunashir they are distributed unevenly; the overwhelming majority are confined to the southwest littoral (the region of the settlement of Alekhino and the caldera of Golovnin Volcano), and 11 species of southern origin (42.3% of the fauna) are found only here. There are two (Metrioptera japonica Bol. and Anechura harmandi Burr.) species prevalent on all three islands. Chorthippus kurilensis kurilensis B.-Bien. is known on Shikotan and Iturup, but was not found on Kunashir, where Ch. kurilensis saltator B.-Bien. supplants it; Kuwayamaea sapporensis Mats. et Shir. thus far has been found only on Shikotan, while Podisma aberrans Ikonn. has been found only on Iturup. Podismopsis konakovi B.-Bien. is evidently an endemic of Iturup, and Podisma kurilensis B.-Bien. is an endemic of Kunashir.

As compared with Japan (Esaki, Takeuchi, 1964) and with the continental part of the Far East, in particular with Primorskiy Kray, where 109 species are known (Bei-Bienko, 1953), the orthopteroid insects fauna of the Kuril Islands is markedly impoverished. This relates especially to Shikotan and Iturup, where the thermophilic forms which are preserved on Kunashir are absent. The inhabitants of Kunashir, and in particular, of its southwestern part, populated by southern thermophilic species create an impression of relative richness of the fauna overall.

Ecologically, the orthopteroid insects living on the islands are represented in the overwhelming majority by mesophilic meadow-forest species. Some of them are associated with herbaceous vegetation (hortobionts, Podismopsis genicularis Shir., P. konakovi B.-Bien., Mecostethus tscherskii Ikonn., Chorthippus biguttulus maritimus Mistsh., Ch. kurilensis kurilensis B.-Bien.), some with woody vegetation (the thamnobionts - Kuwayamaea sapporoënsis Mats. et Shir., Metrioptera japonica Bol., Eirenephilus longipennis Shir., Paropodisma mikado Bol.), and some of the species are typical herpetobionts, living on the surface of the soil (Pteronemobius fascipes nigrofasciatus Mats., P. nitidus yezoensis Shir., Tetrix bipunctata L., T. japonica Bol., Anisolabis maritima Géné., Anechura harmandi Burr.). Some species (Diestrammena japonica Karny., Scapsipedes micado Sauss., Podisma kurilensis B.-Bien.) live in limited zones with a warm microclimate close to hot springs; others (Pteronemobius fascipes nigrofasciatus Mats.), on soils heated by volcanic activity, close to solfataras and fumaroles.

Mass multiplication of the orthopterans and dermapterans has not been observed on the Kuril Islands. A wingless grasshopper (Parapodisma mikado Bol.), a cricket (Pteronemobius fascipes nigrofasciatus Mats.), and an earwig (Anechura harmandi Burr.) are distinguished by comparatively large numbers; the last is very numerous in the southern part of Kunashir in mixed coniferous-broad-leaved forests, where it is encountered on the trunks of trees, in the rotten wood of dead standing and windthrown trunks, as well as on grass and flowers. The wingless grasshopper (Parapodisma mikado Bol.) inflicts damage here and there, eating round the leaves of the butterbur [coltsfoot] (Petasites amplus Kitam.), other tall herbaceous plants, the Kuril bamboo, and the "Maksimovich" alder (Figure 1).

The long-horned grasshopper (Metrioptera japonica Bol.) is quite common on all of the southern islands; the "variegated" grasshopper (Chorthippus biguttulus maritimus Mis.) on Kunashir and Iturup, and the "Kuril" grasshopper (Chorthippus kurilensis kurilensis B.-Bien.) on Shikotan and Iturup. At the same time, many species are rare and are encountered singly; some were found only once each.

With regard to the zoogeographical character and genesis of the fauna of the Kuril orthopteroid insects, it is highly heterogeneous both in relation to their territorial associations and with respect to their origin. As for the type of ranges, three principal groups are distinguished in this fauna: 1) the Manchurian, 2) the Island, and 3) the Transpalearctic; the ecdemic or, possibly, casual species constitute a fourth group. The first and second groups are divided in their turn into a number of subgroups which reflect specific associations between the faunas of neighboring regions.

The Manchurian group (13 species) constitutes the principal nucleus of the fauna, 50%; it is genetically closely associated with the ancient fauna of East Asia. It combines Manchurian species proper, which are prevalent in the south of Primorskiy Kray and in North West China, but which are lacking in Japan (Podisma aberrans Ikonn., Mecostethus tscherskii Ikonn.), the Manchurian-Japanese species (Kuwayamaea sapporensis Mats. et Shir., Conocephalus chinensis Redt., Gampsocleis ussuriensis Adel., Pteronemobius fascipes nigrofasciatus Mats., P. nitidus yezoensis Shir., Tetrix japonica Bol., Mongolotettix japonicus Bol., Podismopsis genicularis Shir.), the Sino-Japanese (Scapsipedes micado Sauss.), and species having a wider distribution beyond the limits of the range of the Manchurian fauna (Gryllotalpa africana Palis., Eirenephilus longipennis Shir.). Many thermophilic species of the Manchurian group are limited within the boundaries of the Kuril range to Kunashir, and are concentrated in the most favorable microclimatic conditions.

The Island group, consisting of island endemics, takes second place in number of species (7). It also breaks down into several subgroups: the Kuril-Japanese, the Sakhalin-Kuril-Japanese, the Sakhalin-Kuril, and the Kuril species proper. Species mainly prevalent in Japan and in the south of Kunashir (Diestrammena japonica Karny. and Parapodisma mikado Bol.) belong to the Kuril-Japanese species. The Sakhalin-Kuril-Japanese species (Metrioptera japonica Bol. and Anechura harmandi Burr.) have a wider range; they are prevalent in Japan, on the Sakhalin, and in all the South Kuril Islands. Both subgroups have close family relationships with the Manchurian fauna. The wingless long-horned grasshopper Diestrammena japonica Karny., which belongs to an Indo-Malaysian tropical genus, is of substantial interest. Its close relative (D. unicolor Brn.) is known in Primorskiy Kray, where it lives in karst caves and in the burrows of mammals (Kurentsov, 1964, 1965a). The long-horned grasshopper Metrioptera japonica Bol. also has a relative on the continent, M. engelhardti Uv. (Bei-Bienko, 1966).

The sole representative of the Sakhalin-Kuril subgroup, Chorthippus kurilensis B.-Bien., which until recently was considered a Kuril endemic, close to the Sakhalin endemic Ch. strelkovi B.-Bien. and its Kunashir subspecies Ch. strelkovi saltator B.-Bien. (Bei-Bienko, 1949), is very interesting. After studying our collections from the Kuril Islands, G. Ya. Bei-Bienko (1966) reached the conclusion that this is one species represented by three well-distinguished subspecies on the Sakhalin, Iturup, and Kunashir. Here we are apparently dealing with the divergent process of early speciation in which three substantially differing subspecies have formed from the initial form under conditions of isolation on different islands. Its very close allied line, the Siberian meadow-forest species Ch. fallax Zub., may be the ancestor of this island species. G. Ya. Bei-Bienko (1966), in a zoogeographical assessment, relates Ch. kurilensis B.-Bien. to the Angaran taiga fauna, as he does another Kuril endemic, Podismopsis konakovi B.-Bien.

We consider species which are prevalent only on the Kuril islands and are not observed at other sites to be Kuril endemics proper . These are Podisma kurilensis B.-Bien. on Kunashir and Podismopsis (Podismacris) konakovi B.-Bien. on Iturup. Of these, the first gravitates to the Manchurian fauna (the close species Podisma aberrans Ikonn. is known in Primorskiy Kray), while the second is evidently a derivative of the Beringian taiga fauna, since its very close relatives are known on the Shantarskiye Islands (Podismopsis insularis Mistsh.) and in Yakutiya (P. gelida Mir.).

The presence of Sakhalin-Kuril and Kuril endemics which are related not to the Japanese, but to the Siberian taiga fauna, confirm the hypothesis of the separative relationships existing in the past between the Sakhalin, the northeastern zones of Asia, and the Kuril archipelago.

The Transpalearctic group is represented by only three species, Tetrix bipunctata L., Chorthippus biguttulus maritimus Mistsh., and the Holarctic Ch. brunneus Thun., of which the second forms a Far Eastern subspecies, prevalent both on the continent and on the islands.

In the zoogeographical analysis of a regional fauna of any group of animals, cosmopolites, ecdemics, and widespread synanthropic species, spread by man, are usually ignored. On the basis of these considerations, the German cockroach (Blatella germanica L.), a synanthropic species, the seaside earwig (Anisolabis maritima Géné.), spread by man throughout the world, and the solitary phase of the Asiatic locust (Locusta migratoria migratoria L.), which is possibly an ecdemic to Kunashir from Hokkaido, were not taken into account in the zoogeographical characterization of the orthopteroid insects of the Kuril Islands.

We present a list of all orthopteroid insects recorded on the Kuril archipelago (Table 2). The material utilized has been presented in an article of G. Ya. Bei-Bienko (1966).