Diplomaragna terricolor ( Attems, 1899 )

Mikhaljova, Elena V. & Sergeev, Maksim E., 2021, Review of the millipedes of the Sikhote-Alin State Nature Biosphere Reserve (Far East of Russia), with detection of the morphological variability of Diplomaragna terricolor (Attems, 1899) (Diplopoda), Amurian Zoological Journal XIII (2), pp. 167-182 : 171-176

Diplomaragna terricolor ( Attems, 1899) Figs 1–24

Diplomaragna terricolor — Mikhaljova 1993: 29; 1998: 27, Figs. 86–87, Map 6.

Material. Russia: 1♂ ( FSCB), Primorsky Krai: Ussuriysky Nature Reserve , mixed forest, litter, 25.09.1977 ; 2♂, 1♀ ( FSCB), Vladivostok, Okeanskaya Station , forest, litter, 26.04.1980 ; 2 ♂ ( FSCB), near Vladivostok, Popova Island , forest litter, 27.09.1980, all leg. E. V. Mikhaljova ; 1♂, 4♀ ( FSCB), Anuchinsky District , near 35 km NW of Arseniev, forest, August 1986, leg. V. D. Bakurov ; 2♂ ( FSCB), Chuguevsky District, Verkhneussuriysky Research Station , ca. 43 ° 50ʹN, 134 ° 15ʹE, 31.07.– 5.08.1998, leg. Yu. M. Marusik ; 1♂ ( FSCB), Khasansky District, about 6 km NW of Zanadvorovka village, Gusevsky Mine , mixed forest on slope, litter, 18.08.2002, leg. E. V. Mikhaljova ; 1♂, 2♀, fragments ( FSCB), Kedrovaya Pad Nature Reserve , forest, pitfall traps, 13.06.2004, leg . V. N. Kuznetsov ; 1♂ ( FSCB), Shkotovsky District, environs of Anisimovka, Litovka Mt. , about 100 m a.s.l., Pinus koraiensis forest, 11.09.2006, leg. A. A. Rodionov ; 2♂, 2♀ ( FSCB), Sikhote-Alin Nature Biosphere Reserve, Blagodatnoe, Ozerny Stream , 29.09.2015, leg. M. E. Sergeev.

Material re-examined. Russia: 1♂, 1♀, 1 juv. ( FSCB), Primorsky Krai: Churuevsky District, Verkhneussuriysky Research Station, Picea forest, litter, 2.09.1975, leg. E. V. Mikhaljova (specimens published by Mikhaljova 1997a); 1♂ ( FSCB), Vladivostok, Okeanskaya Station, forest, litter, 8.05.1977, leg. E. V. Mikhaljova (specimen published by Mikhaljova 1997a); 1♂ ( FSCB), Ussuriysky Nature Reserve, Picea forest, 20.05.1977, leg. E. V. Mikhaljova (specimen published by Mikhaljova 1997a); 1♂, 2 juv. ( FSCB), Ussuriysky Nature Reserve, Abies holophylla forest, 26.10.1977, leg. R. Fedorova (specimens published by Mikhaljova 1997a); 1♂, 1♀ ( FSCB), near Vladivostok, Popova Island, Quercus , Tilia , Betula , Acer , etc., forest, litter, 9.10.1979, leg. E. V. Mikhaljova (specimens published by Mikhaljova 1993); 2♂, 1♀ ( FSCB), near Vladivostok, Popova Island, Quercus , Tilia , Betula , Acer , etc., forest, litter, 7.09.1980, leg. E. V. Mikhaljova (specimens published by Mikhaljova 1993); 1♂, 3 juv. ( FSCB), Sikhote-Alin Nature Biosphere Reserve, floodplain terrace, Yasnaya River, valley Betula forest, 5.06.1984, leg. M. N. Gromyko (specimens published by Mikhaljova 1993); 1♂, 1 juv. ( FSCB), Gamova Peninsula, environs of Telyakovsky Cape, leaved forest, near stream, litter, 17.06.2003, leg. E. V. Mikhaljova (specimens published by Mikhaljova and Marusik 2004); 1♂, 1♀ ( FSCB), Lazovsky Nature Reserve, Amerika Cordon, 15.05.2007, leg. S. A. Shabalin (specimens published by Mikhaljova 2009); 1♂, 7 ♀ ( IBSS), Khabarovsky Krai: Sikhote-Alin, Mt. Ko, 1000 m, 6.07.2007, leg. P. V. Budilov (specimens published by Mikhaljova 2016)

Distribution. Russia: Far East (Primorsky Krai, southern part of Khabarovsky Krai).

Remarks. This species was originally described from the environs of Vladivostok, Russia ( Attems 1899). Later, based on topotype material, a re-description of this species was provided ( Shear 1990).

In the course of our study of males of D. terricolor from the Blagodatnoe of the Sikhote-Alin Reserve, the unusual structure of their gonopods has been revealed (see Figs 16 , 20 ). The gonopods differs in the configuration of the posterior angiocoxal processes with the very high apical oval outgrowths (a) (vs not high apical oval outgrowth according to the original description and re-description by Shear) and with broad mesal protrusions (m) carrying finger-shaped processes (b) directed to body dorsum (vs finger-shaped processes directed strictly forward according to the re-description by Shear).

Additional investigation of males of this species from different territories of the Primorsky and Khabarovsky Krai allowed discovering of the specific variations in the gonopod structure of D. terricolor . The basic diagnostic characters of D. terricolor are the configuration of the posterior gonopod’s posterior angiocoxal process with arms and outgrowths of different size, and the architecture of the colpocoxite distal part. The above material appears to show certain variation exactly in the configuration of the posterior angiocoxal process. Thus, the apical oval outgrowth (a) of posterior angiocoxal process ranges from very low to very high ( Figs. 1–16 ). Also, the finger-shaped process (b) is straight ( Figs. 11, 12 , 16 ) or more ( Figs. 1–3, 5–6, 8–9 , 13 ) or less ( Figs. 4, 7, 10 , 14, 15 ) strongly curved forward; its length varies too.

In addition, the variation of the coxal process of the male leg 11 (p) is revealed. Thus, its size ranges from small to large ( Figs. 21– 24 ). An increase in the size of this coxal process correlates with an increase in the size of the apical oval outgrowth (a) (see Figs. 13 and 21 ; 16 and 24 ). Moreover, we can distinguish two distinct extreme forms of the gonopods + male coxae 11. The first form (males from the Anuchinsky District of the Primorsky Krai and from the environs of Ko Mountain, the Khabarovsky Krai): a very low apical oval outgrowth (a) of the posterior angiocoxal process, a strongly curved forward process b, a small coxal process of leg 11 ( Figs. 1, 2 , 13 , 17 , 21 ). The second form (males from the Blagodatnoe, Sikhote-Alin Nature Reserve,): a very high apical oval outgrowth (a) of the posterior angiocoxal process, straight (directed to dorsum) process b, large coxal process of leg 11 ( Figs. 12 , 16 , 20 , 24 ). The differences between these extreme forms are linked by a complete series of transitions. At that, the gonopods of a male from the floodplain terrace of the Yasnaya River (Sikhote-Alin Reserve) ( Fig. 9 ) belong to an intermediate transitional form in contrast to the second extreme gonopod form of the males from Blagodatnoe (Sikhote-Alin Reserve). It should be noted that the second gonopod form and forms close to one are more common for males of the eastern part of the Primorsky Krai. While the first gonopod form and forms close to one were mainly recorded in males from the central and southern parts of the Primorsky Krai as well as in the male from the south of Khabarovsky Krai. However, both forms can occur together. For example, males of two opposite forms ( Figs. 6, 11 ) were found together in the same locality of the Popova Island, south of Primorsky Krai.

The species is rather variable. However, the present material being unrepresentative, we have preferred not to make conclusion on the nature of variability. An investigation of this phenomenon is a very considerable project in itself, which can only be realized in future with further accumulation of abundant, representative material and using molecular genetic methods too. Now, it can only be assumed that the morphological variability of this species is due to the different ecological conditions of the eastern, southern and central territories of the Primorsky Krai and the Khabarovsky Krai.

Also, it is necessary to add to the description of D. terricolor the presence of a process on the male coxa 11 since this character was omitted in the re-description of D. terricolor (see Shear 1990).

Occurrences in the natural landmarks of the Sikhote-Alin State Nature Biosphere Reserve: Blagodatnoe, Yasnaya.

Figures

Figs. 1–12. Diplomaragna terricolor (Attems, 1899). Variation in structure of the posterior angiocoxal process of posterior gonopod. 1 — from Anuchinsky District, Primorsky Krai; 2 — from Mt. Ko, Khabarovsky Krai; 3 — from Vladivostok, Okeanskaya Station, Primorsky Krai; (1st copy); 4 — from Vladivostok, Okeanskaya Station, Primorsky Krai; (2st copy); 5 — from Kedrovaya Pad Nature Reserve, Primorsky Krai; 6 — from Popova Island, Primorsky Krai; (1st copy); 7 — from Ussuriysky Nature Reserve, Primorsky Krai; 8 — from Lazovsky Nature Reserve, Primorsky Krai; 9 — from Sikhote-Alin Nature Biosphere Reserve (floodplain terrace, Yasnaya River), Primorsky Krai; 10 — from Chuguevsky District, Verkhneussuriysky Research Station, Primorsky Krai; 11 — from Popova Island, Primorsky Krai; (2st copy); 12 — from Sikhote-Alin Nature Biosphere Reserve, Blagodatnoe, Ozerny Stream, Primorsky Krai; a — apical outgrowth; b — finger-shaped process; m — mesal protrusion. Scale in mm (0.5)

Figs. 13–16. Diplomaragna terricolor (Attems, 1899). Posterior angiocoxal processes of posterior gonopods. 13 — from Mt. Ko, Khabarovsky Krai;14 —from Vladivostok, Okeanskaya Station, Primorsky Krai; 15 — from Lazovsky Nature Reserve, Primorsky Krai; 16 — from Sikhote-Alin Nature Biosphere Reserve, Blagodatnoe, Ozerny Stream, Primorsky Krai; a — apical outgrowth; b — finger-shaped process; m — mesal protrusion. Scales: 100 μm

Figs. 17–20. Diplomaragna terricolor (Attems, 1899). Gonopods, caudal view. 17 — from Mt. Ko, Khabarovsky Krai; 18 — from Vladivostok, Okeanskaya Station, Primorsky Krai; 19 — from Lazovsky Nature Reserve, Primorsky Krai; 20 — from Sikhote-Alin Nature Biosphere Reserve, Blagodatnoe, Ozerny Stream, Primorsky Krai; a — apical outgrowth; b — finger-shaped process; m — mesal protrusion. Scales: 100 μm

Figs. 21–24. Diplomaragna terricolor (Attems, 1899). Coxae of male leg pair 11, front view. 21 — from Mt. Ko, Khabarovsky Krai; 22 — from Vladivostok, Okeanskaya Station, Primorsky Krai; 23 — from Lazovsky Nature Reserve, Primorsky Krai; 24 — from Sikhote- Alin Nature Biosphere Reserve, Blagodatnoe, Ozerny Stream, Primorsky Krai; p — coxal process. Scales: 100 μm Рис. 21–24. Diplomaragna terricolor (Attems, 1899). Коксы 11-й пары ног самца, виΑ спереΑи: 21 — с горы Ко в Хабаровском крае; 22 — из ВΛаΑивостока, станция Океанская; 23 — из Αазовского заповеΑника в Приморском крае; 24 — из Сихотэ- АΛинского заповеΑника (урочище БΛагоΑатное, кΛюч Озёрный) в Приморском крае; р — коксаΛьный отросток. Масштабы: 100 μm