Willowsia arunachalensis, 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 : 110-112

Willowsia arunachalensis sp. nov.

urn:lsid:zoobank.org:act:8AEC0266-A90C-40E2-B23C-B82C9A363BD4

Figs 4–6 , Tables 1–2 , 4

Diagnosis

Body segments with distinct pigment patches, intensely coloured laterally; Abd. III pigmented; Scales of long basal rib type, absent on legs and antennae, present on manubrium; labral papilla with 2–4 denticles; Abd. I–IV with 2, 4, 2, 8 central mac on each side respectively, Abd. IV with 13 lateral mac.

Etymology

The specific epithet was given after the type collection state Arunachal Pradesh ( India).

Type material

Holotype INDIA • ♀ (on slide); Arunachal Pradesh, West Kameng district, Bomdila town, Bomdila Forest Inspection Bungalow ; 27°15.957′ N, 92°25.520′ E; 8337 ft a.s.l.; 29 Mar. 2023; G.P. Mandal leg., reg. no. 3386/H14; NZC.

Paratypes INDIA • 4 ♀♀ (on slides), 18 specs in alcohol; same collection data as for holotype; reg. no. 3387/H14; NZC .

Description

MEASUREMENTS. Average body length in adult up to 3 mm ( Fig. 4A–B ).

COLOUR. Ground colour pale yellow, blue pigment scattered as distinct patches all over body, especially on lateral side. Eye patches dark blue; blue transverse band between eyes; ventral side of head blue pigmented. Antennae pigmented, darker towards tip. Legs with blue pigment, furcula unpigmented ( Fig. 4A–B ).

SCALES. Scales of long basal rib type ( Figs 4D , 5A ); present on body and ventral manubrium. Antennae and legs devoid of scales.

HEAD. Eyes 8+8, G and H smaller. Antenna 2.57 × as long as cephalic diagonal. Antennal segment ratio as I: II: III: IV = 1: 2.42: 2.26: 3.1. Ant. IV with bilobed apical bulb, many sensory setae and normal ciliated setae ( Fig. 5B ). Dorsal cephalic chaetotaxy as Fig. 5C , with four antennal (An), four median (M 1 –M 4) and seven sutural (S 0, S 2 –S 5, S 4i, S 5i) mac. Labral formula 4/5, 5, 5, prelabral setae ciliated and other smooth, four labral papillae each with 2–4 denticles ( Figs 4C , 5D ). Labial palp with a thick lateral process, tip not reaching at apex of labial papilla ( Fig. 5E ). Labial triangular setae as MREL 1 L 2, all ciliated ( Fig. 5F ).

THORAX. Thoracic mac as Fig. 5G ; Th. II with two medio-sublateral (in figure T2), nine posterior mac, Th. III with 13 mac on each side. Trochanteral organ with 15–17 smooth spiny setae, 11–12 in ‘L’ arrangement and five present in inner area ( Fig. 5H ). Unguis with 4 inner teeth,1 paired basal and 2 unpaired, one external basolateral tooth present. Hind leg paired and two unpaired teeth distance from unguis base 21 µm, 32 µm, 40 µm respectively, between two unpaired teeth 8 µm. Unguiculus lanceolate with outer edge serrate, tenent hair thick and serrated with clavate tip ( Figs 4E , 6A ).

ABDOMEN. Abd. IV 2.6 × as long as Abd. III along dorsal midline. Dorsal chaetotaxy of Abd. I–IV as shown in Fig. 6B–C . Abd. I with two central mac (m3, m4) and two sens. Abd. II with four central mac (a2, m3, m3e, m5) and 6–7 lateral mesochaete, two sens. Abd. III with two central (a2, m3), four lateral mac (am6, pm6, p6, m7a) and two two sens ( Fig 6B ). Abd. IV with 8 central mac (A4, A6, A6e, A7e, B4–B6, Si, Sm), 13 lateral mac and 7 S-setae ( Fig. 6C ). Ventral tube with 4+4 anterior long and other 10+10 ciliated setae, 8+8–10+10 smooth lateral flap setae, posterior side with 1+1 smooth setae ( Fig. 6D ). Tenaculum quadridentate with a stout single seta. Manubrial plaque with five ciliated seate, two pseudopores visible ( Fig. 6E ). Basal part of dens a little thick, uncrenulated dens 2.45 × as long as mucro. Mucro bidented with single basal spine ( Fig. 6F ).

Remarks

Willowsia arunachalensis sp. nov. is similar to W. ieti Yosii, 1971 in chaetotaxy pattern, although differs from the latter in having lanceolate hind unguiculus, spine number of trochanteral organ and absence of scale on antennae, details given in Table 4 . The new species is closest to W. cassagnaui Zhang, 2015 for both species have no scales on Ant. I and legs. However, the latter has 3+3 mac on Abd. I and rounded labral papillae. Willowsia buski ( Lubbock, 1870) and the new species share a similar body chaetotaxy though they differ in colour pattern, Abd. IV chaetotaxy, labral papillae structure, trochanteral setae number etc. ( Table 4 ). A detailed comparison of all the related species of Willowsia with W. arunachalensis is given in Table 1 along with chaetotaxic comparison of the same ( Table 2 ).

Figures

Fig. 4. Willowsia arunachalensis sp. nov. A. Holotype, ♀ (reg. no. 3386/H14), habitus, dorso-lateral view. B. Paratype, ♀ (reg. no. 3387/H14), habitus, dorsal view. C–E. Paratype, ♀ (reg. no. 3387/H14). C. Labral papillae. D. SEM of body scales. E. Fore claw (SEM image). Scale bars: A–B = 500 µm; C = 20 µm; D–E = 10 µm.

Fig. 5. Willowsia arunachalensis sp. nov., paratype, ♀ (reg. no. 3387/H14). A. Body scale. B. Apex of Ant IV. C.Dorsal head chaetotaxy (right side). D. Labium. E. Lateral process of labial palp (right side). F. Labial triangle (left side). G. Dorsal chaetotaxy of Th II-III. H. Trochanteral organ. Scale bars: A–B, D–F = 20 μm; C = 100 μm; G = 200 μm; H = 50 μm.

Fig. 6. Willowsia arunachalensis sp. nov., paratype, ♀ (reg. no. 3387/H14). A. Fore leg. B. Dorsal chaetotaxy Abd I–III. C. Abd IV dorsal chaetotaxy (right side). D. Anterior face of ventral tube. E. Manubrial plaque (left side). F. Distal part of dens with mucro. Scale bars: A, E–F = 50 μm; B = 200 μm; C = 100 μm; D = 20 μm.