Willowsia sikkimensis, Mandal & Mandal & Suman & Bhattacharya, 2024

Mandal, Pritha, Mandal, Guru Pada, Suman, Kusumendra Kumar & Bhattacharya, Kaushik Kumar, 2024, Two new species and one new record of Willowsia Shoebotham, 1917 (Collembola: Entomobryidae) from the Eastern Himalayan region of India, European Journal of Taxonomy 935, pp. 101-121 : 103-110

Willowsia sikkimensis sp. nov.

urn:lsid:zoobank.org:act:CFAA8B12-FD08-4A58-A42D-728210F73FA7

Figs 1–3 , Tables 1–3

Diagnosis

Blue pigment present on Abd. III–V and as patches on lateral side of head, Th. III, Abd. II; pigment sometimes deep on Th. III. Head with 9+9 antennal and 9+9 sutural mac. Th. II with 5+5 medio-sublateral and 19–21 posterior mac; Abd. I–IV with 3, 5, 3, 13 central mac on each side respectively and Abd. IV with 23 lateral mac.

Etymology

The specific epithet is given after the type specimen collection state Sikkim ( India).

Type material

Holotype INDIA • ♀ (on slide); collected from Sikkim, North Sikkim District, Lachen Village ; 27°42.565′ N, 88°33.723′ E; 7824.80 ft a.s.l.; 9 Sep. 2022; G.P. Mandal leg.; in leaf litter; reg. no. 3287/H14; NZC.

Paratypes INDIA • 3 ♀♀ (on slides), 25 specs in ethyl alcohol; same collection data as for holotype; reg. no. 3388/ H14; NZC .

Description

MEASUREMENTS. Body length up to 2.4 mm without appendages ( Fig. 1A–C ).

COLOURATION. General body colour pale yellow; deep blue pigment present on Abd. III–V and diffusely on Th. III, Abd. II ( Fig. 1A–B ), sometimes Th. III deeply pigmented ( Fig. 1C ). Coxa and distal part of hind femur with blue patch. Eye patches dark blue, transverse band present between two eyepatches, little blue ting present behind eyes.

SCALES. Spinulate type of scales present all over body ( Fig. 2A ), Ant. I–II, legs up to femur. Ventral side of manubrium with slender scales.

HEAD. Eyes 8+8, G and H smaller. Antennae 2.47 × as long as head diagonal. Ratio of antennal segments I: II: III: IV = 1: 1.56: 1.57: 2.45. Ant. IV with many sensory setae and bilobed bulb distally. Dorsal cephalic region with nine antennal (An), four median (M 1 –M 4) and nine sutural (S 0 –S 6, S 4i, S 5i) mac ( Fig. 2B ). Interocular setae as p, s, t. Labral setae formula as 4/5, 5, 4; pre-labral setae ciliated, others smooth; labral papillae conical ( Fig. 2C ). Labial triangle with five ciliated (MREL 1 L 2) and five smooth setae ( Fig. 2D ), tip of lateral process of labial papilla reaching apex of labial papilla ( Fig. 2E ).

THORAX. Tergal mac as shown in Fig. 2F . Th. II with two medio-median (m2, m2i) (in Figure T1 ), five medio-sublateral (m4, m4i, m4p, m4pi, m5) (in Figure T2 ), 20–21 posterior mac (p5i sometimes absent), two sens present. Th. III with 18 median and six lateral mac (a6, a6i, p5, p6, m6, m6e), two sens present on lateral side. Trochanteral organ with 53–55 smooth setae arranged in square ( Fig. 2G ). Unguis with basal paired, two unpaired inner teeth each located 22 µm, 36 µm and 46 µm distance from unguis base respectively, 13µm distance between two inner unpaired teeth (hind claw); unguiculus lanceolate with outer edge serrate. Thick, smooth clavate tenent hair present, slightly longer than inner side of unguis ( Fig. 3A ).

ABDOMEN. Dorsal chaetotaxy as Fig. 3B–C . Abd. I with three central mac (m2–m4), one ms and one sens. Abd. II with five central mac (a2, m3, m3ep, m3e, m3ea), two sens and one ms, m5 present. Abd. III with three dorso-central (a2, a3, m3), five lateral mac (am6, pm6, p6, m7a, p7) and two sens. Abd. IV 13 central (A3–A6, Ae3, Ae5, Ae7, B3–B6, Si, Sm) and 23 lateral mac and with 12 S-setae as Figure 3C . Ventral tube with 5+5 long and 17–19 median ciliated setae on each side of anterior face, about 17–20 lateral flap setae, posterior side with 1+1 smooth and 1+1 ciliated setae ( Fig. 3D ). Manubrial plaque with 11 ciliated setae, three pseudopores clearly visible ( Fig. 3E ). Uncrenulated part of dens 1.26 × as long as mucro. Bidented mucro with sub-equal teeth, basal spine tip reaching subapical tooth ( Fig. 3F ).

Remarks

This new species is greatly different from the species of Willowsia described from India and the world both in chaetotaxy and colour pattern ( Tables 1–2 ). Willowsia sikkimensis sp. nov. is similar to the Chinese species W. zhaotongensis in head chaetotaxy, scale morphology and its position on body ( Chai & Ma 2017). However, the two species are noticeably dissimilar in antennal and body chaetotaxy, a labial triangle with a different posterior row formula and a few other characters listed in Table 3 .

Figures

Fig. 1. Willowsia sikkimensis sp. nov., habitus. A. Holotype, ♀ (reg. no. 3287/H14). B–C. Paratype, ♀ (reg. no. 3388/H14.). Scale bars: A–B = 1 mm; C = 500 µm.

Fig. 2. Willowsia sikkimensis sp. nov., paratype, ♀ (reg. no. 3388/H14). A. Body scale type. B. Dorsal chaetotaxy of head.C. Labrum.D. Labial triangle (right side). E. Lateral process of labial papilla E (right side). F. Chaetotaxy of Th. II−III. G. Trochanteral organ. Scale bars: A, D = 20 μm; C, E, G = 50 μm; B = 100 μm; F = 200 μm.

Fig. 3. Willowsia sikkimensis sp. nov., holotype, ♀ (reg. no. 3287/H14). A. Hind foot complex. B. Chaetotaxy of Abd. I–III (right side). C. Chaetotaxy of Abd IV (right side). D. Anterior face of ventral tube. E. Manubrial plaque (left side). F. Mucro. Scale bars: A, D = 100 μm; B = 200 μm; C, E = 50 μm; F = 25 μm.