Oligaphorura igori, Shveenkova & Babenko, 2022

Shveenkova, Yulia B. & Babenko, Anatoly B., 2022, Three new Oligaphorura species (Collembola: Onychiuridae) of the marcuzzii-group from the Caucasus, Zootaxa 5116 (4), pp. 579-590 : 586-588

Oligaphorura igori sp. nov.

Figs 4 , 17–18 , 23–26 ; Table 1

Type material. Russia: holotype, male, Northwestern Caucasus, Krasnodar Krai, ~ 45 km E of Sochi, Krasnaya Polyana, upper station of Galaktika G 1 cable car, Laura River basin, [43.6952°N, 40.3585°E], fir-beech forest with maple, ~ 1600 m alt., litter, 20.06.2018, N. Kuznetsova & A. Saraeva leg. Paratypes: 4 female, 2 juvenile males, 1 juvenile, same data as holotype. The types are kept in the MSPU collection .

Diagnosis. Body cylindrical. Dorsal sensilla on body well-marked. Anal spines absent. Pseudocellar formulae: 43/133/44354 (dorsal), 11/000/1112 (ventral), 222 (subcoxal). Ventral psx hardly visible. AIIIO with 5 papillae, PAO slightly larger than nearest pso, with 3–4 lobes. Labium of ABD-type (papilla C low with short terminal sensilla, E absent). Th. III without lateral ms. Distal whorls (A+T) of each tibiotarsus with 9 setae. Furcal remnant of schoetti - type, cuticular furrow quite distinct.

Description. Size 0.56–0.64 mm, holotype 0.57 mm. Colour white in alcohol. Body cylindrical. Granulation regular, slightly coarser around dorsal pso (10–12 granules) ( Fig. 23 ).

Number of pso: 43/133/44354 (dorsal) and 11/000/1112 (ventral) ( Figs 23–25 ). Ventral psx poorly expressed, almost invisible, 0/000/001(0)000 in number ( Fig. 24 ). Each upper Sc of legs I–III with 2 pso.

Antennae shorter than head. Ant. IV with 3 slightly thickened S-setae, subapical organite present, microsensillum located in proximal row of setae ( Fig. 17 ). AIIIO on Ant. III consisting of 5 papillae, 5 guard setae, 2 sensory rods, 2 granulated clubs (external one larger) and lateral ms. Ant. I–II with 9 and 13 setae, respectively. Antennal area slightly marked. PAO located laterally in a cuticular furrow, with 4(3) lobes, slightly larger than nearest pso. Maxilla unmodified. Maxillary palp simple with 1 basal seta and 2 sublobals. Labrum with 4/342 setae. Labial palp with 6 proximal setae and 10 guards, four of guards spiniform as usual, six others longer but also rather short. Four of the latter guards located on site of reduced papilla E, and other two—next to papillae B and D. Basomedian and basolateral fields of labium with 4 and 5 setae, respectively. Terminal sensilla of papillae A, B and D thickened, papilla C lower with short terminal sensillum, papilla E absent (labium of ABD type) ( Fig. 26 ).

Dorsal setae poorly differentiated into macro—and microsetae, symmetrical in general ( Fig. 23 ). S-setae well marked and distributed as follows: 11/022/22211 (dorsally), 0/000/00011 (ventrally) and 0, 0, 1 on lower Sc of legs I–III. Head with an axial unpaired seta a0, but without a0’, d0 absent as usual for the genus. Setae p1 on head at level with p2. Th. I with 5+5 dorsal setae. Lateral ms present only on Th. II and absent on Th. III. Terga of Th. II–Abd. III each with 3–4 pairs of axial setae. On Abd. VI, setae a0 and a2 approximately same in size, setae a1 half as long as a0. Thoracic sterna with 0-1-1 setae each side of ventral line. Ventral chaetotaxy as in Figs 24, 25 .

Upper subcoxae of legs I–III with 4, 3, 3 setae, respectively. Tibiotarsal chaetotaxy with 18–19–17 setae, respectively: distal whorl (T+A) with 9 setae (setae T2 and T3 absent), 7 B-setae (B7 absent only on Ti III), an unpaired seta M and one seta (or two setae on the second leg) of C-whorl. Unguis with neither inner nor lateral teeth, unguiculus narrow, with a narrow basal lamella, about 0.3–0.4 times as long as inner edge of unguis ( Fig. 18 ). VT with 6+6 proximal setae and 2+2 setae at base. Furcal remnant of schoetti - type, cuticular furrow quite distinct ( Figs 4 , 24 ). Each lateral anal valve with a0 and 2a1 setae, unpaired valve with a0, 2b1, 2b2 and 7 setae in c-row (b0 and a1 absent). Anal spines absent.

Etymology. The species honours Igor Kaprus’, our Ukrainian friend and colleague, in appreciation of his significant contributions to the taxonomy of Onychiurinae , as well as his extensive faunistic researches in the mountain regions of Ukraine and Russia.

Affinities. Oligaphorura igori sp. nov. can be distinguished from all other known congeners of the marcuzzii -group characterized by the ABD-type of the labium and two pso on each upper subcoxae due to the presence of nine distal setae on each tibiotarsus, whereas O. montivaga sp. nov. and O. tatianae sp. nov. have 11 setae in that position, vs only 6 in O. kremenitsai and O. humicola (see Table 1 ). There are also some other sound differences: the types of the furcal area (the schoetti - type in O. igori sp. nov., O. montivaga sp. nov., O. tatianae sp. nov. vs the humicola - type in O. kremenitsai and O. humicola ), pso-formulae (43/133/ 44354 in O. igori sp. nov., 43/133/44(5) 364 in O. tatianae sp. nov., 43/144/ 44354 in O. montivaga sp. nov., 42/144/ 33354 in O. kremenitsai and 42/133/ 33354 in O. humicola ) and the rather short unguiculus in O. igori sp. nov. (about 0.3–0.4 times as long as inner edge of unguis).

A single specimen of a very similar form has also been found in an adjacent area (Western Caucasus, Caucasus Nature Reserve, Republic of Adygea, Guzeripl cordon, [43.9945°N, 40.1421°E], fir-beech forest, 712 m alt., litter, 26.06.2017, N. Kuznetsova & A. Geraskina leg.). It shares the main diagnostic features (pseudocellar formulae, the types of the labium and the furcal remnant) with O. igori sp. nov., but it shows a different number of distal setae on the tibiotarsi. Unfortunately, we do not have enough material to describe it at present.

Figures

FIGURES 1–8. Types of furcal area in Oligaphorura species. 1–5, S or schoetti-type: 1–2, two different interpretations, Oligaphorura tatianae sp. nov.; 3, Oligaphorura montivaga sp. nov.; 4, Oligaphorura igori sp. nov.; 5, O. psammophila Shveenkova & Babenko, 2021; 6, A or absoloni-type, O. jiguliensis Shveenkova & Babenko, 2021; 7, H or humicola-type, O. kremenitsai; 8, D or differens-type, O. imosolica Shveenkova & Babenko, 2021.

FIGURES 13–18. Oligaphorura montivaga sp. nov. (13–14), Oligaphorura tatianae sp. nov. (15–16), Oligaphorura igori sp. nov. (17–18): 13, antenna, different views; 14, tip of leg II; 15, tip of leg I; 16, antenna, different views; 17, antenna, different views; 18, tip of leg I. Scales. Figs 13, 16, 17: 0.05 mm; 14, 15, 18: 0.025 mm.

FIGURES 23–26. Oligaphorura igori sp. nov.: 23, dorsal chaetotaxy; 24, ventral chaetotaxy of abdomen; 25, ventral chaetotaxy of head; 26, labial palp with basomedian and basolateral parts of labium (spiniform guards not shown). Scales. Figs 23–25: 0.05 mm; 26: 0.025 mm.