Homidia linhaiensis, Shi, Shi-Di, Pan, Zhi-Xiang & Qi, Xin, 2009

Shi, Shi-Di, Pan, Zhi-Xiang & Qi, Xin, 2009, A new species of the genus Homidia Börner, 1906 (Collembola: Entomobryidae) from East China, Zootaxa 2020, pp. 63-68 : 63-68

Homidia linhaiensis sp. nov.

Figs 1–22 , Tab. 1

Type material. Holotype, female on slide, China: Zhejiang Province: Linhai City, 18. iv. 2008, collection number S3048, collected by Zhi-Xiang Pan & Xin Qi. Paratypes: 15 females and 3 males on slide and 20 in alcohol, same data as holotype. Deposited in the College of Life Science, Taizhou University, China.

Description. Size. Maximum body length: 3.85 mm.

Colour pattern. Ground colour yellowish in alcohol ( Figs. 1–3 ). Eye patches dark blue. Ant. III and IV with dark blue pigment. One pair of dark blue spots present on middle of dorsal Th. III. Scattered light blue pigment present on frontal and interocular areas of head, lateral sides of Th. II–III, and coxae of legs.

Head. Eyes 8+8, G and H smaller than others, and sometimes invisible ( Fig. 4 ). Antenna 1.9–3.2 times as long as cephalic diagonal; antennal segment ratio I: II: III: IV = 1: 1.3–1.6: 1.4–1.5: 1.8–2.5; Ant. III organ with 2 rod-like sensory setae ( Fig. 5 ); Ant. IV apical bulb bilobed ( Fig. 6 ). Dorsal cephalic chaetotaxy (after Szeptycki, 1973) with 6 antennal (A), 3 ocellar ( O) and 6 sutural (S) macrochaetae ( Fig. 4 ). Labral papillae absent. Prelabral and labral setae (after Szeptycki, 1973) as 4/ 5, 5, 4, all smooth; seta a2 slightly shorter than a1, and apparently longer than b2 ( Fig. 7 ). Five papillae A–E on labial palp (after Fjellberg, 1998 /99) with 1, 4, 0, 4, 4 guard setae respectively; lateral process (l.p.) with tip not reaching apex of papilla E ( Fig. 8 ). Setal formula of labial base as M, R, E, L1 and L2, setae E and L1 smooth, others ciliate ( Fig. 9 ). Maxillary palp simple with 1 terminal hair; maxillary outer lobe with 3 sublobal hairs and 1 basal seta ( Fig. 10 ).

Thorax. Dorsal chaetotaxy (after Szeptycki, 1979) shown in Fig. 11 . Th. II with 4 medio-medial (m1, m2, m 2i, m 2i 2), 4 (5) medio-sublateral (m4, m 4i, m4p, m4pi; m4pi2 rarely present), and 26–29 posterior macrochaetae (p4ip and p4p often absent). Trochanteral organ with 41–71 smooth spiny setae ( Fig. 12 ). Inner differentiated tibiotarsal setae slightly ciliate, most distal one on hind leg smooth. Tenent hair clavate and slightly longer than inner edge of unguis. Unguis with 4 (2 paired and 2 unpaired) tiny inner teeth and 2 lateral teeth. Unguiculus lanceolate with outer edge slightly serrate ( Fig. 13 ). Coxal macrochaetal formula as 3/4+2, 3/4+3 ( Fig. 14 ).

Abdomen. Dorsal chaetotaxy (after Szeptycki, 1979) shown in Figs. 15 and 16 . Abd. I with 10 (11) macrochaetae (a2, a3, a5, m2, m 2i, m3, m4, m 4i, m4p, m5; a 5i rarely present) on each side. Abd. II with 6 central (a2, a3, m3, m3e, m3ea, m3ep) and 1 lateral (m5) macrochaetae on each side. Abd. III with 2 central (a2, m3) and 5 lateral (am6, pm6, m7, p6, p7) macrochaetae on each side ( Fig. 15 ). Abd. IV with 10–13 macrochaetae on anterior part of each side, arranged in irregular transverse row; extra macrochaeta (A2) always present anterior to transverse row; posterior part with 10–16 macrochaetae (A4a, A4–6, B4–6, Ai1–2, Ae4–8; A4a and Ae8 rarely present) ( Fig. 16 ). Ventral tube anterior face with many ciliate setae, among them 3+3 as macrochaetae, line connecting proximal (Pr) and external-distal (Ed) macrochaetae oblique to median furrow ( Fig. 17 ); posterior face with 5 subapical smooth and numerous ciliate setae ( Fig. 18 ); lateral flap with 9 smooth and 19–22 ciliate setae ( Fig. 19 ). Ratio of manubrium: (dens + mucro) = 1: 1–1.1. Dens with 6–16 spines; basal setae (after Szeptycki, 1973) bs1 and bs2 spiny and multilaterally ciliate, bs1 apparently shorter than bs2; proximal-inner seta (pi) ciliate, apparently thinner, slender and longer than bs1 and bs2 ( Fig.20 ). Mucro bidentate with subapical tooth obviously larger than apical one; basal spine short, with tip only reaching subapical tooth ( Fig. 21 ). Tenaculum with 4+4 teeth and 1 large, multi-laterally ciliate basal seta ( Fig. 22 ).

Ecology. In litter of radish on farmland.

Etymology. The new species is named after the type locality.

Remarks. The new species is characterized by the colour pattern with two small blue spots on dorsal Th. III and dark pigment on lateral sides of Th. II–III and coxae, the presence of 5+5 lateral macrochaetae on Abd. III, 9 smooth setae on each lateral flap of ventral tube, and a pair of A2 macrochaetae on anterior part of Abd. IV.

Homidia linhaiensis is most similar to H. pentachaeta Li & Christiansen, 1997 in having a pair of dark blue spots on dorsal Th. III, similar labral and labial basal setae, 5+5 lateral macrochaetae on Abd. III, 4 medio-medial macrochaetae on Th. II, 5 smooth setae on posterior face of ventral tube and in the morphology of dental basal setae bs1, bs2 and pi. However, it can be distinguished from H. pentachaeta by the absence of transverse dark band on Abd. III and by the presence of macrochaeta a3 on central Abd. III, 3/4+2, 3/4+3 macrochaetae on coxae I–III, 9 smooth setae on lateral flap and a pair of A2 macrochaetae on anterior part of Abd. IV. The new species is also close to H. socia Denis, 1929 b and H. tiantaiensis Chen & Lin, 1998 in having 3 large ciliate setae on anterior face of ventral tube and in the chaetotaxy of Abd. I–II and IV. However, it can be distinguished from the two species above by body colour pattern, 5+5 lateral macrochaetae on Abd. III and 9 smooth setae on lateral flap. The main differences between the new species and six other Chinese species are given in Table 1 .

Figures

FIGURES 1 – 3. Homidia linhaiensis sp. nov. 1, dorsal view of body, showing colour pattern; 2 – 3, lateral view of body, showing colour pattern.

FIGURES 4 – 13. Homidia linhaiensis sp. nov. 4, dorsal chaetotaxy of head; 5, Ant. III organ; 6, apical bulb on Ant. IV; 7, labrum; 8, labial palp; 9, labium; 10, maxillary palp and maxillary outer lobe; 11, dorsal chaetotaxy of thorax; 12, trochanteral organ; 13, inner differentiated tibiotarsal setae and foot complex on hind leg.

FIGURES 14 – 22. Homidia linhaiensis sp. nov. 14, coxal macrochaetae (A: coxae of fore legs, B: coxae of mid legs, C: coxae of hind legs); 15, dorsal chaetotaxy of Abd. I – III; 16, dorsal chaetotaxy of Abd. IV; 17, anterior face of ventral tube; 18, posterior face of ventral tube; 19, lateral flap of ventral tube; 20, basal part of dens; 21, apex of dens and mucro; 22, tenaculum.

Tables

TABLE 1. Main characters differentiating between seven Homidia species found in.

	linhaiensis . sp. nov.	pentachaeta Li & Christiansen, 1997	tiantaiensis Chen & Lin, 1998	socia Denis, 1929 b
Labral papilla	absent	absent	absent	4 tiny
Coxal macrochaetal formula	3/4+2, 3/4+3	3/4+1, 3/4+2	3/4+2, 3/4, 3	3/4+1, 3/4, 3
Labial basal seta E	smooth	smooth	smooth	ciliate
Labial basal seta L1 Antennal setae (A) on dorsal head	smooth 6	smooth 4–6	smooth 4	ciliate 4
Seta a3 on Abd. III	absent	present	absent	present
Lateral macrochaetae on Abd. III	5	5	4	4
A2 macrochaetae on anterior part of Abd. IV	present	absent	present	present
Smooth setae on posterior face of ventral tube	5	5	5	2
Smooth setae on lateral flap	9	6	5	6
Dental spines	6–16	31–45	29–36	15–20
Ungual inner teeth	4	3	3	3
Dental basal setae bs1 Dental basal setae bs2 Dental basal setae pi	spiny, thick, short spiny, thick, short slender, long	spiny, thick, short spiny, thick, short slender, long	spiny, thick, short slender, long spiny, thick, short	slender, long slender, long slender, long
Comparison of setal length Position of line connecting macrochaetae Pr and Ed to median furrow of ventral tube	pi> bs2> bs1 oblique	pi> bs2> bs1 oblique	bs2> pi> bs1 oblique	pi> bs2> bs1 parellel
Distribution in China	Zhejiang	Jiangsu	Zhejiang	Anhui, Guangxi, Jiangsu, Zhejiang, Fujian
continued.