Pseudachorutes cf. kangchenjungae Yosii, 1966

Babenko, Anatoly, Kuznetsova, Natalia, Nakamori, Taizo & Shveenkova, Yulia, 2021, A review of Pseudachorutes Tullberg, 1871 (Collembola, Neanuridae) from the East Asia, with description of six new species, Zootaxa 4938 (4), pp. 351-391 : 378-380

Pseudachorutes cf. kangchenjungae Yosii, 1966

Figs 76–83

Examined material. Russia: 1 juvenile, Far East, Southern Primor’e , 30 km SE of Chuguevka, mixed forest, 44°1.32’N 134°9.02’E, 500 m alt., 11 August 2017 ; 1 male and 1 female, same region, Sikhote-Alin State Nature Reserve, Brusnichnaya River , mixed (cedar, poplar, spruce, elm, white fir, birch, etc.) forest in valley, 45°38.9’N 137°0.58’E, ~ 200 m alt., 6 August 2017 ; 1 female, same Nature Reserve , coniferous forest with Rhododendron brachycarpum , 45°8.30’N 135°53.22’E, ~ 930 m alt., 08 August 2017 ; 2 females and 6 juveniles, Khabarovsk Territory, Komsomolsk State Nature Reserve, Gorin River , mixed coniferous-broadleaf forest, rotting wood, 50°44.25’N 137°25.43’E, ~ 250 m alt., 10 August 2018 ; 1 juvenile, same region, but Anyuinski National Park, Tormasu River, mixed coniferous-broadleaf forest, rotting wood, 49°18.2’N 137°34.2’E, ~ 200 m alt., 07 August 2018 . All N. Kuznetsova, A. Kuprin & A. Geraskina leg.; 1 male, Khabarovsk Territory, Komsomolsk State Nature Reserve, spurs of Mount Sergol , aspen-oak forest with fern, 50°44.3’N, 137°24.12’E, ~ 250 m alt., pit-trapes, 10–20 July 2018 ; 2 females, same Nature Reserve , mixed herbaceous forest (cedar-broadleaf-birch), 50°44.38’N, 137°23.87’E, ~ 230 m alt., pit-trapes, 20 July–03 August 2018 ; 1 specimen, sex unknown, same region, vicinity of Komsomolsk , mixed herbaceous forest, 50°36.72’N, 137°1.6’E, pit-trapes, 02–17 July 2018 . All O. V. Kuberskaya leg.

Main diagnostic characters. Medium sized species. Labrum with 4/2334 setae, labium with 3 proximal setae and without seta L, both its basomedial and lateral parts with 4 setae, 4 perilabial setae present. Mandible with at least 4 teeth. Head with both a0 and d0, Th. I with 4+4 setae, Th. II with a2, Th. II–III with 4 ordinary setae (a3, a4, m4 and p4) additionally to S in dorso-external group, Abd. I–III usually with setae a3, m3 and m 4 in front of p3 and p4 (=S), i.e. dorso-lateral group with four ordinary setae. Mucro with basal «swelling». Each anal valve with 3 hr-setae.

Description based on the examined material. Body wide and somewhat flattened, length (without antennae) of adults from 0.71 to 2.45 mm. Colour unknown (only cleared specimens available), but probably dark and uniform. Tegument granulation rather coarse.

Antennae slightly shorter than head, Ant. III–IV fused dorsally, ventral separation well marked. Ant.IV with trilobed apical vesicle, external ms, subapical or and seta i present; sensilla (S1–S4, S7–S8) on dorsal side of Ant.IV clearly differentiated, ventral side with many truncate or slightly clavate sensilliform setae ( Fig. 79 ). Antennal organ of Ant. III typical, inner sensilla small, inclined to one side and located in cuticular fold, sgv only slightly longer than sgd, ventral ms present. Ant. I–II with 7 and 12 setae, respectively.

Head with 8+8 subequal ocelli. PAO elliptic, consisting of 10–14 vesicles, ratio of its longer diameter to ocellus B as 1.5–1.7: 1 ( Fig. 80 ). Buccal cone elongated ( Fig. 82 ). Maxilla styliform, with tiny apical teeth, lamellae unseen. Mandible with at least two small teeth between apical and basal ones ( Fig. 81 ). Distal edge of labrum prolong and pointed, number of labral setae usually as: 4/2334. Main part of labium with three proximal ordinary setae, seta L absent, labial organites invisible; submentum and mentum with usual set of four setae each, i.e. 4+4 ( Fig. 82 ). Perilabial area with 4+4 setae.

Dorsal setae short and smooth, sensilla longer, about as 2.0 –2.3 times longer than ordinary setae, their number as usual: 22/11111. Chaetotaxy more or less stable with some asymmetrical abnormalities, interocular part of head always with some irregular extra setae ( Fig. 76 ) present even in juveniles, a0 usually present. Th. I with 4+4(5) setae. Th. II with a2-seta and lateral ms present, dorso-external group with three setae (a3–a4, m4) in front of p3–p4. Th. III identical but without a2 and ms ( Fig. 77 ). Abd. I–III usually with 3 setae (a3, m3–m4) in front of p3–p4, sometimes one of them absent. Abd. V with sensilla p3 shifted anteriorly and both a2 and p2 present at least in full sized specimens ( Fig. 78 ).

Thoracic sterna without setae. Ventral tube with 4+4 setae, no seta on sternum of Abd. I, Abd. II with 5(6)+5 sternal setae, Abd. III with 8–11 such setae. Tenaculum with 3+3 teeth as usual. Furca not especially long, reaching posterior border of Abd. II. Manubrium with 9+9 (10) setae on main part, 4–5 setae on each basolateral lobe and 2–3(5) basal setae in line. Dorsal side of dens with six setae, hyaline field on its ventral side about as large as mucro length. Mucro curved, lateral lamella high but short forming basal «swelling» ( Fig. 83 ). Each anal valve with three tiny hr-setae.

Legs I–III with typical number of setae: 1, 2, 2 setae on upper subcoxae, 0, 3, 2–3 setae on lower subcoxae, 3, 7, 7–8 setae on coxae, 6, 6, 6 on trochanters, 13, 12, 11 setae on femora and 19, 19, 18 setae on tibiotarsi. Unguis with strong basal tooth on inner edge, lateral teeth invisible.

Remarks. The identification of our materials as P. kangchenjungae ( Table 1) is based on the «three pillars»: a well-developed «ventral file» on Ant. IV, only 3 proximal setae and no seta L on the labium and mucro with a basal «swelling». Initially, this species was described from the highlands of the Himalayas (4160 m alt.) based on a single female. Later a single female called as P. sp. prope kangchenjungae was described from the mountainous regions of North Korea ( Weiner & Najt 1985). In general, our materials are consistent with both the first and second descriptions. They differ from the Himalayan material only in the different sizes of the proximal setae on the labium (subequal according to Yosii 1966), the pointed labral tip (truncate on fig. 12B in Yosii 1966) and 6 setae on dens (7 dental setae present according to Yosii 1966). The only character, which differs our material from the description of Weiner & Najt (1985), is the absence of labial organites. Unfortunately, Weiner & Najt (1985) did not describe chaetotaxy in details simply added that it coincides with that figured by Yosii (la chétotaxie dorsale coïnside avec la chétotaxie dessinée par Yosii). Judging by fig. 12K in Yosii (1966), our specimens have more complete chaetotaxy than those from Himalaya and Korea. For example, on this figure, Th. I has only 3+3 setae (usually 4+ 4 in full-size specimens), Th. II lacks a2 (always present even in small juveniles with 2+2 setae on Th. I). Therefore, doubts about the identity of the materials from the Far East of Russia with true kangchenjungae , obviously, remain.

Two other congeners, P. prosimplex Weiner & Najt, 1985 and P. morulifer sp. nov., having clearly developed «ventral file» on Ant. IV, are known in the region under study. These species are easy to distinguish from P. kangchenjungae due to such unique feature as compound vesicles in the PAO, which therefore looks like a «morula» (see above).

Distribution. The species was originally described from Nepal and as Pseudachorutes cf. kangchenjungae Yosii, 1966 was reported from North Korea, Sikhote-Alin State Nature Reserve and Khabarovsk Territory.

Figures

FIGURES 76–83. Pseudachorutes cf. kangchenjungae Yosii: 76, head chaetotaxy; 77, chaetotaxy of Th. I–III; 78, chaetotaxy of Abd. V; 79, Ant. III–IV (ventral view); 80, PAO and ocelli; 81, mandible; 82, buccal cone; 83, mucro (different views). Scales: Figs 76–78 = 0.1 mm, 79–83 = 0.01 mm.