CHAPTER 3

SECTION 5. Order COLEOPTERA

Family TENEBRIONIDAE (darkling beetles)

Until recently only 3 species of darkling beetles, mentioned in the papers of H. Kôno (Kôno, 1935a, 1936a) and S. Kuwayama (Kuwayama, 1967), have been known on the Kuril Islands. Our collections have doubled the list of species, bringing it up to 7.

The fam. Tenebrionidae, which is so rich and diverse in drier regions, is extremely impoverished on the Kuril archipelago, and is represented by a very small complex of mesophilic species belonging to various ecological groups. In terms of eco-area delimitation, species which are associated with coniferous-broadleaved forests (Gonocephalum recticolle Motsch. and Stenophanes strigipennis Mars.), which live on sandy sea shores (Emypsara riederi Fald., Phaleromela subhumeralis Mars., and Caedius sp.), and subcortical dwellers (Hypophloeus linearis F. and Hypophloeus sp.) are distinguished. They are distributed unevenly over the territory of the Kuril Range. Representatives of the first group live on the southern islands: Gonocephalum recticolle Motsch. only on Kunashir, Stenophanes strigipennis Mars. on all the southern islands (Shikotan, Kunashir, Iturup); it reaches Urup to the north, but is scanty everywhere. Two species have thus far been observed in bark beetle nests only on Iturup in Japanese stone pine; however, their discovery on Kunashir and Urup as well cannot be excluded. The inhabitants of sea shores which live in the sand are the most widely distributed: Phaleromela subhumeralis Mars., which is encountered throughout the entire Range from Shikotan to Shumshu, and Emypsara riederi Fald., which so far is known on the southern and central islands (Shikotan, Kunashir, Iturup, Urup). The latter should undoubtedly also be found in the north of the archipelago as well, since it is encountered on Kamchatka and the Aleutian Islands.

The trophic associations of the Kuril darkling beetles are quite diverse. Gonocephalum recticolle Motsch. is a phytophage; the alimentary specialization of Stenophanes strigipennis Mars. has not been established; the small darkling beetles which live in the galleries of bark beetles may be regarded as specialized predators, while the species which live at sea shores may be regarded as polyphage predators (this relates at least to Emypsara riederi Fald.; by our observations, not only the beetles, but the larvae as well, engage in predation).

The limited number of Tenebrionidae species on the Kuril Range does not permit an extensive zoogeographical characterization of their fauna. In that case, a judgment can be made only regarding individual zoogeographical elements of it, which have proven to be quite diverse. Thus, species associated with broadleaved forests gravitate toward the Japanese fauna. One of them, Gonocephalum recticolle Motsch., has a range of the Kuril-Japanese type. The other, Stenophanes strigipennis Mars., belongs to an East Asian genus, and is also an Island, Sakhalin-Kuril-Japanese, endemic. The two species which are confined to the sea shores (Phaleromela subhumeralis Mars. and Emypsara riederi Fald.) represent a legacy of the Okhotsk fauna. Only Hypophloeus linearis F. has a wide transpalaearctic range which is still inadequately explored in Siberia and the Far East.

Nearly all the darkling beetles on the Kuril Islands are encountered sporadically, singly or in relatively small numbers. Emypsara riederi Fald., which at some sites on sandy sea shores is quite numerous, constitutes an exception, but does not strike the eye, since it is well masked in the sand.

SYSTEMATIC LIST OF SPECIES

1. Gonocephalum recticolle Motsch. K - env. of Alekhino set., July 1-5, 1962, 3 spec., in broadleaved forest and sea shore sand; Zyryanskaya Bight near Alekhino, July 4, 1962, 11 spec., in sand and on grass on shore among wrinkled rose brakes. Observed only on the southwest coast of K, where it is encountered sporadically. A Kuril-Japanese species. Distributed on K and in Japan (on many islands). A very close species, G. terminale Reich. (Kaszab, 1952), live on the continent (Primorskiy Kray, the Korean Peninsula).

2. Caedius sp. K - shore of Lake Goryacheye, August 16, 1962, 1 spec., in sand on shore. Representatives of the genus Caedius are ancient inhabitants of sandy sea shores.

3. Phaleromela subhumeralis Mars. Yuzhno-Kuril'sk and Alekhino settlements; Sh, U, P, Shu - according to the data of H. Kôno (Kôno, 1935d, 1935c) and S. Kuwayama (Kuwayama, 1967). We have not found it, although it is evidently quite common. An inhabitant of sea shores. An Okhotsk species, distributed throughout the Kuril Range, on Sakhalin, Kamchatka, and in Japan (Hokkaido, Honshu). The range of this species is still insufficiently explored.

4. Emypsara riederi Fald. (Figure 35). K - env. of Alekhino set., July 2, 1962, 1 spec.; August 28, 1964, 1 spec., sea shore, A. K. Tsimbalyuk; env. of Sernovdosk set., July 31, 1961, 1 spec., mixed forest, on the ground; U - Okhotsk coast near Lake Tokotan, August 13, 1963, 11 spec., sea shore, in sand and at sites of sea kale clumping; Sh - Nepokorennyy Cape; I - according to the data of S. Kuwayama (Kuwayama, 1967). Lives in sand on sea shores; at some sites, in the water itself. The beetles and larvae have the ability to dig into the sand, where they engage in predation, eating the larvae of flies and amphipod (Orchestia ochotensis) young, and possibly various organic residues. The larvae are very mobile and agile. A fairly large number of beetles are found in rotting laminaria leaves cast up on the shore, which in places form solid layers covering the entire shore. In connection with their protective coloration (imitating the color of the sand) and the concealed mode of living, it is not possible to find the beetles immediately; nevertheless, their numbers may be very great in particular areas. An Okhotsk species, widely distributed on the Kuril Range, observed on the southern islands (Sh, K, I) and Urup, but should doubtless be encountered in the northern region of the archipelago, since it is known on Kamchatka, Sakhalin, the Aleutian Islands (?), and in Japan (Hokkaido, Honshu); it has also been mentioned for North East China.

5. Hypophloeus linearis F. I - env. of Kuybyshevo set., August 23, 1961, 8 spec., from galleries of bark beetles in Japanese stone pine. It is rarely encountered on the Kuril Range. A Transpalaearctic species with an insufficiently explored range. A characteristic inhabitant of bark beetle nests in coniferous species. Known on I (finding it on K, U, and other islands, as well as on Sakhalin is entirely probable), in Western Siberia, and Europe.

6. Hypophloeus sp. I - env. of Kuybyshevo set., August 22, 1961, 1 spec., from galleries of Dryocoetes orientalis Kurenz. in Japanese stone pine; env. of Burevestnik set., August 25, 1961, 1 spec., from galleries of Pityogenes foveolatus Egg. Not found on other islands.

7. Stenophanes strigipennis Mars. K - env. of Alekhino set., July 22, 1962, 1 spec.; August 26, 1964, 1 spec., coniferous-broadleaved forest, A. K. Tsimbalyuk; I - env. of Lesozavodsk set., July 20, 1963, 1 spec., broadleaved-dark coniferous forest; env. of Kuril'sk, August 18, 1961, 1 spec., in oak groves; S. Kuwayama (Kuwayama, 1967) cites it for Sh (Malokuril'sk set.) and U as well under the name of S. rubripennis Mars. Lives in coniferous-broadleaved forests; encountered singly on the ground. Its biology has not been studied. A representative of an East Asian genus. An Island endemic whose range encompasses Sakhalin, the southern region of the Kuril archipelago, and Japan (Hokkaido, Honshu).