Willowsia cassagnaui, Zhang, Feng, 2015

Zhang, Feng, 2015, Some Willowsia from Nepal and Vietnam (Collembola: Entomobryidae) and description of one new species, Zootaxa 3905 (4), pp. 489-499 : 490-494

Willowsia cassagnaui sp. nov.

Figs 1−15

Types. Holotypes: female on slide, Nepal: Machapuchare, alt. 2200 m, above Pokhara, forest of large trees ( Quercus semicarpifolia Sm. In Rees , Acer sp., rhododendrons, bamboos etc.), dry moss on a branch, 26.x. 1976, P. Cassagnau leg. (# Nep. 76.51). Paratypes: 4 female and 4 young specimens on slides, same data as holotype. Two paratypes in NJAU and others in MNHN.

Description. Body length up to 1.82 mm.

Ground colour pale yellow in alcohol. Blue pigment forming irregular patterns on body. Ant. I−IV gradually becoming darker from anterior to posterior. A transverse band between the eye patches and a small lateral patch behind each eye patch. Lateral patches present from Th. II to Abd. VI. A pair of lighter small patches on median Th. III and Abd. I. Two transverse bands on posterior Abd. II and III. A pair of large median and small posterior patches on Abd. IV. Legs slightly pigmented. Furcula pale ( Fig. 1). Scales on body pointed, striate heavily with basal ribs longer than distal ones ( Fig. 2); scales on ventral manubrium obviously narrower than those on terga ( Fig. 3). Scales absent on antennae, legs, ventral tube and dens.

Antenna twice as long as cephalic diagonal. Antennal segments ratio as I: II: III: IV = 1: 1.9: 1.8: 2.9. Ant. III organ not clearly seen. Antennal apical bulb bilobed. Labral margin with 4 rounded papillae. Labral intrusion slightly curved ( Fig. 4). Tip of lateral process of labial palp nearly reaching apex of labial papilla ( Fig. 5). Subapical chaeta of maxillary outer lobe slightly stronger than apical one; 3 hairs on sublobal plate ( Fig. 6). Labial chaeta R 0.4−0.5 x the length of M ( Fig. 7). Dorsal cephalic chaetotaxy with 6 antennal (An) and 5 sutural (S) mac ( Fig. 8).

Th. II with 10 posterior mac; median mac absent; p 4−6 and p 5 pi as mac. Th. III with 11 mac ( Fig. 9). Thoracic S-chaetae not clearly seen. Metatrochanteral organ with about 14 smooth spiny chaetae; 10 in arms, V-shaped and 4 between arms ( Fig. 10). Unguis with 4 inner teeth; basal inner pair with tip reaching 0.45 distance from base of ventral edge, median one at 0.71 and distal one 0.87 distance from base. Unguiculus lanceolate with outer edge slightly serrate. Tenent hair subequal to unguis in length ( Fig. 11).

Abd. IV four times Abd. III in length along dorsal midline. Abd. I with 3 (m 2−4) mac and 2 S-chaetae; ms internal to sens. Abd. II with 3 (a 2, m 3, m 3 e) central, 1 (m 5) lateral mac and 2 sens. Abd. III with 2 (a 2, m 3) central, 3 (am 6, pm 6, p 6) lateral mac, 1 ms and 2 sens. Abd. IV with 7 central mac and about 12 sens; homology of anterior three mac unclear; 3 lateral sens obviously shorter than others ( Fig. 12). Accessory mic of bothriotrichal complexes on Abd. II−IV unmodified. Ventral tube anteriorly with about 14 ciliate chaetae on each side ( Fig. 13), 2 of them larger than others; posteriorly with 11 chaetae, apical two smooth; each lateral flap with 7 smooth and 1 ciliate chaetae ( Fig. 14). Distal smooth part of dens 1.9−2.5 x mucro in length ( Fig. 15).

Etymology. The new species is named after P. Cassagnau, who collected the specimens.

Remarks. Willowsia cassagnaui sp. nov. is similar to W. ieti Yosii, 1971 in most features. It differs from it in colour pattern, lateral process of labial palp longer with tip nearly reaching apex of labial papilla, slightly curved labral intrusion, fewer chaetae on trochanteral organ (14 vs> 20), lanceolate unguiculus, presence of mac m 2 on Abd. I, and absence of scales on Ant. I ( Table 1). Lateral stripes, transverse band on Abd. II, and paired lighter small patches on median Th. III, Abd. I and Abd. IV are present in W. cassagnaui sp. nov., but are absent in W. ieti , which possesses a pair of small spots on Abd. II. The slightly curved labral intrusion of the new species is rarely seen in entomobryids. The shape of the unguiculus is also a characteristic separating them, as it is lanceolate in new species and truncate in W. ieti .

Type locality. Nepal: Khumbu Himal, Yaral near Pangpoche, alt. 4100 m.

Specimens examined. 4 females on slides, Nepal: Machapuchare, alt. 2740 m, level site with large trees (oaks, rhododendrons, bamboos), moss and lichen on a branch, 25.x. 1976, P. Cassagnau leg. (# Nep. 76.40); 8 females on slides, Nepal: Gosaikund, alt. 3660 m, upper edge of the fir forest and juniper heath, moss and liverworts on a rock, moderately humid, 20.xi. 1978 (# Nep. 78.59). Eight specimens on slides in NJAU and others in MNHN.

Additions to original description. Body scales heavily striate with pointed tips ( Fig. 16); present on Ant. I, body and ventral side of manubrium; scales on manubrium narrower than those on body, some of them extremely elongate ( Fig. 17). Tip of lateral process of labial palp not reaching apex of labial papilla ( Fig. 18). Subapical chaeta of maxillary outer lobe stronger than apical one; 3 hairs on sublobal plate ( Fig. 19). Labial chaeta R 0.7 x the length of M. Dorsal cephalic chaetotaxy as in Fig. 20. Metatrochanteral organ with more than 20 smooth spiny chaetae ( Fig. 21). Ventral tube anteriorly with about 22 ciliate chaetae on each side, 2 of them much larger than others ( Fig. 22). Manubrial plaque with about 6 ciliate chaetae; pseudopores not clearly seen. Distal smooth part of dens about twice mucro in length. Th. II with 10 posterior mac; median mac absent. Th. III with 11 mac ( Fig. 23). Abd. I with 2 (m 3−4) mac. Abd. II with 3 (a 2, m 3, m 3 e) central and 1 (m 5) lateral mac. Abd. III with 2 central (a 2, m 3) and 3 (am 6, pm 6, p 6) lateral mac ( Fig. 24). Abd. IV with 7−8 central and about 14 lateral mac; homology of anterior four central mac unclear, the second mac close to midline often as a mesochaeta ( Fig. 25). Accessory mic of bothriotrichal complexes on Abd. II−IV unmodified or absent.

Remarks. The type specimens in Natural History Museum, Geneva, could not be studied as permission was not given to borrow it. The type locality (Yaral) is located between the two new sites for this species recorded here. The Gosaikund record is 100 km directly east of the type locality, Machapuchare about 75 km west of Yaral. Our specimens from these two new populations comply well with Yosii’s (1971) original description, particularly in colour and tergal chaetotaxy (Th. II‒Abd. III), so that they are designated as W. ieti Yosii here. We added further details of mouthpart, chaetae on dorsal and ventral head, ventral tube and total body chaetotaxy. For differences between W. ieti and W. cassagnaui sp. nov. see the remarks above.

Tables

TABLE 1. Comparison between W. cassagnaui sp. nov. and W. ieti.

Characters	W. cassagnaui sp. nov.	W. ieti .
Labral papillae	rounded	conical
Labral intrusion	slightly curved	U-shaped
Ratio of R/M on labium	0.4−0.5	0.7
Lateral process of labial palp	long	short
Chaetae on metatrochanteral organ	about 14	>20
Scales on Ant. I	absent	present
Unguiculus	lanceolate	truncate
Anterior face of ventral tube	about 14	about 22
Tergal chaetotaxy Abd. I Abd. IV	3+3 mac 7+7 central	2+2 mac 7−8+7−8 central
Willowsia ieti Yosii, 1971 Figs 16–25