Willowsia japonica ( Folsom, 1897 )

Zhou, Rong, Pan, Zhixiang & Ma, Yitong, 2021, Three new species Willowsia (Collembola: Entomobryidae) from China and notes on W. japonica, Zootaxa 4991 (1), pp. 73-92 : 87-91

Willowsia japonica ( Folsom, 1897)

Figs 73−90

Complement to description. Body length up to 2.21 mm. Eye patches dark blue. Blue pigment present on antennae, lateral side of head and legs. Lateral patches present on Th. II−III and Abd. I−V. Abd. III & IV also with an irregular transverse band ( Fig. 73 ).

Scales. Scales narrow and short rib type, present on head and terga ( Figs 74−75 ).

Head. Antennae 0.45−0.47 times as long as body. Antennal segments ratio as I: II: III: IV = 1: 1.88−2.09: 1.76−1.91: 2.18−2.47. Distal part of Ant. IV with many smooth sensory chaetae, normal ciliate chaetae, a pin chaeta and a bilobed apical bulb ( Fig. 76 ). Sensory organ of Ant. III as 2 rods ( Fig. 77 ). Sensory organ of Ant. II as 1 rods ( Fig. 78 ). Dorsal cephalic chaetotaxy as 4 antennal (An), 4 median (M) and 7 sutural (S) mac. Ps2 absent. Interocular mes as p, q, r, s, t. Eyes 8+8, G and H smaller ( Fig. 79 ). Lateral process of labial palp curved, with tip not reaching apex of labial papilla ( Fig. 80 ). Subapical chaeta of maxillary outer lobe thin, subequal to apical one; 3 smooth hairs on sublobal plate ( Fig. 81 ). Labial triangular chaetae as MREL 1 L 2, all ciliate and R 0.50−0.67 length of M( Fig. 82 ).

Thorax.Th. II with 1 (m2) mac on T1 area, 3 (m4, a5, m5) mac on T2 area, 7−8 (p5pe sometimes absent) posterior mac and 2 posterior mesochaetae on each side. Th. III with 13 mac, 2 sens on each side ( Fig. 83 ). Trochanteral organ with about 18 smooth spiny chaetae ( Fig. 84 ). Unguis with 4 inner teeth, one pair located 0.35−0.40 from base of inner edge of unguis, distal unpaired two respectively at 0.65−0.67 and 0.84−0.88 distance from base. Unguiculus acuminate and outer edge serrate. Tenent hair thick with clavate tip, longer than inner side of unguis ( Fig. 85 ).

Abdomen. Abd. IV about 4.12 times as long as Abd. III along dorsal midline. Abd. I with 3 (m2, m3, m4) mac, 1 ms and 1 sens, ms not inner to sens. Abd. II with 1 (a2) mac on A1 area, 2(m3, m3e) mac on A2 area, 1 (m5) lateral mac and 2 sens. Abd. III with 1 (a2) mac on A4 area, 1 (m3) mac on A 5 area, 3 (am6, pm6, p6) lateral mac, 1 ms and 2 sens. Abd. IV with 7 central and 11 lateral mac. Accessory mic of bothriotrichal complexes of Abd. II−IV unmodified ( Figs 86−87 ). Manubrial plaque dorsally with 4 ciliate chaetae and 2 pseudopores ( Fig. 88 ), ventrally with 9 ciliate chaetae on each side ( Fig. 89 ). Uncrenulated dens 2.07−2.10 times as mucro in length. Mucro bidentate, two teeth subequal and tip of basal spine reaching subapical tooth ( Fig. 90 ).

*Because of my carelessness, W. pseudoshi Ma, 2016 should be W. pseudoshiae Ma, 2016 .

Remarks. The species, W. japonica ( Folsom, 1897) , is the only one which have scales of narrow and short rib type among the known Chinese Willowsia species. It is widely distributed in Japan, Hawaii and China (Xinjiang, Hubei, Jiangsu and Zhejiang) (Zhang, et al. 2011). Our specimens agree with the previous descriptions in apical antennal bulb, colour pattern, sculpture and distribution of scales, chaetotaxy of body.

Figures

FIGURES 73−74. Willowsia japonica (Folsom, 1897). 73, habitus; 74, scales. Scale bars: 73 = 500μm; 74 = 10μm.

FIGURES 75−85. Willowsia japonica (Folsom, 1897). 75, scale; 76, apex of Ant. IV; 77, distal part of Ant. III; 78, distal part of Ant. II; 79, dorsal chaetotaxy of head; 80, lateral process of labial palp; 81, maxillary outer lobe; 82, labium; 83, chaetotaxy of Th. II−III; 84, trochanteral organ; 85, foot complex. Scale bars: 75 = 2μm; 76−78, 80−82, 84 & 85 = 20μm; 79 & 83 = 100μm. Material examined. Two adult female on slides, China, Shaanxi Province, Zhouzhi County, Mazhao Town, 108 National Road, 1386 km, 34°03′35″ N, 108°11′47″ E, 15, July, 2012, collection number: 1115, by Yitong Ma with entomological aspirator. All deposited in NTU.

FIGURES 86−90. Willowsia japonica (Folsom, 1897). 86, chaetotaxy of Abd. I−III; 87, chaetotaxy of Abd. IV; 88, manubrial plaque; 89, ventro-apical part of manubrium; 90, distal part of dens and mucro. Scale bars: 86 & 87 = 100μm; 88−90 = 20μm.