Homidia quadrimaculata, Pan, Zhi-Xiang, 2015

Pan, Zhi-Xiang, 2015, Two new species of Homidia (Collembola, Entomobryidae) and a key to species in the genus from Zhejiang Province, China, Zootaxa 4034 (3), pp. 515-530 : 523-528

Homidia quadrimaculata sp. nov.

Figs 30–52 , Table 2

Holotype. 1♀ on slide, China, Zhejiang Province, Wenzhou City, Yueqing, Caijialin village 28°25'53.10"N, 121°0'42.04"E, elev. 151± 3 m, sample number S4448, 16.I.2015, Z-X Pan, Y-H Pan and C-C Si.

Paratypes. 2♀ on slides and 3 adults in ethanol, same data as holotype. All types deposited in TZU.

Etymology. Named after four dark spots (Latin: quadrus+macula) on central thorax.

Body length up to 2.68 mm.

Ground colour pale, white in ethanol. Eye patches dark blue; a transverse dark band between eye patches. Head with two stripes laterally and posteriorly. Antennae of adults specimens broken at second or third joints, Ant. I with distal and medial black-violet rings; Ant. II–III blackish violet, joint regions unpigmented. Thorax with four central triangular dark patches (hemispherical in juveniles) and two lateral stripes, anterior margin of Th. II slight pigmented. Abd. II with irregular small spots dorsally and laterally with 2 dark stripes. Abd. III entirely darkly pigmented except laterally two circular unpigmented spots. Abd. IV with two bands medially and posteriorly, joining with the sub-medial, median one with medial and lateral extensions to anterior margin, laterally with dark stripes. Posterior half of Abd. V with dark band. Coxae with dark pigment ( Figs 30–32 ). Juveniles with similar but lighter colouration; antennae gradually becoming darker from Ant. I to Ant. IV; semicircular central patches on thorax ( Fig. 33 ).

Eyes 8+8, G and H smaller than others difficult to observe under the light microscope; eye patch with 3 chaetae, p largest ( Fig. 34 ). Antennal length more than twice cephalic diagonal. Ant. I with 3 dorsal and 4 ventral basal smooth mic ( Fig. 35 ).Ant. II with 5 basal smooth mic ( Fig. 36 ) and with 2 distal rod-like S-chaetae ( Fig. 37 ). Ant. III organ with 2 rod-like and 3 short guard S-chaetae ( Fig. 38 ). Apical bulb of Ant. IV bilobed ( Fig. 39 ). Dorsal cephalic chaetotaxy with 3 antennal (A), 3 ocellar ( O) and 5 sutural (S) mac ( Fig. 34 ). Prelabral and labral chaetal formula as 4/5, 5, 4, all smooth. Chaetal formula of labial base as MRel1L2, e and l1 smooth, others ciliate, chaetae on posterior labium not expanded ( Fig. 40 ). Labial palp papillae A–E with 0, 5, 0, 4, 4 guard chaetae, respectively. Lateral process (l.p.) thin with tip reaching apex of papilla E. Hyaline plate with 1 main (H) and 2 accessory (h1, h2) chaetae ( Fig. 41 ). Maxillary outer lobe with 1 apical, 1 subapical chaetae and 3 sublobal hairs on sublobal plate; length of subapical chaeta subequal to that of apical one ( Fig. 42 ). Mandible with 4/5 (left/right side) teeth.

Complete body sens as 22/122(about 39)3, ms as 10/10100. Th. II with 4 (m1, m2, m 2i and m 2i 2) mediomedial, 3 (m4, m 4i and m4p) medio-sublateral and 3 S-chaetae (ms antero-internal to sens); posterior region with 27–32 mac; p4, p 4i and p5 as mac, p6 as mic. Th. III with 32–36 mac and 2 sens; p5 and p6 as mac ( Fig. 43 ). Coxal macrochaetal formula as 3 (1 pseudopore) /4+1, 3 (3 pseudopores) /4+2 (2 pseudopores) ( Fig. 44 a–c). Trochanteral organ with 28–32 smooth chaetae ( Fig. 45 ). Tenent hair capitate. Unguis with 4 inner, 2 lateral and 1 outer teeth. Unguiculus lanceolate with outer edge slightly serrate, inner tibiotarsus with weakly ciliated chaetae ( Fig. 46 ).

Abd. IV length 5–7 times as Abd. III along dorsal axis. Abd. I with 10 (a1–3, a5, m2–4, m 2i, m 4i and m4p) mac (ms anterior to sens). Abd. II with 6 (a2, a3, m3, m3e, m3ea and m3ep) central and 1 (m5) lateral mac. Abd. III with 2 (a2 and m3) central and 4 (am6, pm6, p6 and m7a) lateral mac ( Fig. 43 ). Abd. IV with about 37 elongate and 2 normal length sens; area A7 with 8–12 mac arranged in irregular transverse row; areas A8–10 with 1-1(2)-2(3) (A6, B4–6; A5 and Ae7 rarely present). Abd. V with 3 sens, middle one external to m3; chaetae m3a and a 5i as mic ( Fig. 48 ). Anterior face of VT with many ciliate chaetae, 3+3 as mac, line connecting proximal (Pr) and externaldistal (Ed) mac oblique to median furrow; posterior face with 6 subapical smooth chaetae; lateral flap with 6 smooth and 11–16 ciliate chaetae on each side ( Fig. 49 ). Manubrial plaque with 3 pseudopores and 9–12 ciliate chaetae ( Fig. 50 ). dens with about 47 inner spines; basal chaetae (bs1 and bs2) spiny, bs1 shorter than bs2; chaeta pi unclear ( Fig. 51 ). Mucro bidentate with subapical tooth larger than apical one; basal spine short, with tip reaching subapical tooth; distal smooth part of dens shorter than mucro in length ( Fig. 52 ). Tenaculum with 4+4 teeth and 1 large, multi-laterally basal ciliate chaeta.

Ecology. Found in leaf litter of Eriobotrya japonica (Thunb.) and Myrica rubra (Lour.) .

Note: *: other distribution records based on our sample: Guangdong Province, Guangxi Zhuang Autonomous Region, Guizhou Province.

Remarks. Homidia qualrimaculata sp. nov. is identified by its unique colour pattern, 4 (6) mac on areas A8– 10 of Abd. IV, ms anterior to sens on Abd. I, and median sens external to m3 on Abd. V.

The new species is most similar to Homidia sichuanensis Jia et al. 2010 in colour pattern on head and abdomen, dorsal chaetotaxy of head and thorax and subapical smooth chaetae on posterior face of VT. But, it can be separated from the latter by four dark patches centrally on thorax (2 on H. sichuanensis ), chaeta l1 on labial base smooth (ciliate on H. sichuanensis ), chaetae m5 on Abd. I and A4 on Abd. IV as mic (mac on H. sichuanensis ). The detailed morphological differences are listed in Table 2 .

Figures

FIGURES 30 – 33. Colour pattern of H. quadrimaculata sp. nov.: 30 – 32. Adult: 30 – 31. Lateral view; 32. Dorsal view; 33. Dorsal view of juvenile.

FIGURES 34 – 42. H. quadrimaculata sp. nov.: 34. Cephalic chaetotaxy; 35. Basal part of Ant. I; 36. Smooth chaetae on basal Ant. II; 37. Distal part of Ant. II; 38. Ant. III organ; 39. Apical bulb and tip of Ant. IV; 40. Labial and posterior labial chaetal formula; 41. Labial palp; 42. Maxillary outer lobe. (Figures 34 – 37, 39 dorsal view; Figures 38, 40 – 42 ventral view).

FIGURES 43 – 47. H. quadrimaculata sp. nov.: 43. Dorsal chaetotaxy of Th. II – Abd. III; 44. Coxal chaetal formula (a. Fore leg; b. Mid leg; c. Hind leg); 45. Trochanteral organ; 46. Distal tibiotarsus and claw of hind left leg (lateral view); 47. Tenaculum.

FIGURES 48 – 52. H. quadrimaculata sp. nov.: 48. Dorsal chaetotaxy of Abd. IV – V; 49. Ventral tube (lateral view); 50. Manubrial plaque (dorsal view); 51. Basal part of dens (dorsal view); 52. Distal part of dens and mucro (lateral view).

Tables

TABLE 2. Detailed comparison between H. quadrimaculata sp. nov. and H. sichuanensis.

Characters	H. quadrimaculata sp. nov.	H. sichuanensis
Colour pattern
Dark pigment rings on Ant. I	present	absent
Patches on central thorax	4	2
Dark pigment on Abd. III	present	absent
Dark pigment on legs	absent	present
Chaeta L(l) 1 on labial base	smooth	ciliate
Chaeta m5 on lateral Abd. I	mic	mac
Chaeta a2 on area A4 of Abd. III	mac	mic
Chaeta A4 on area A8 of Abd. IV	mic	mac
Chaeta p0 on medial Abd. V	mic	mac
Teeth on inner edge of unguis	4	3
Distribution	Zhejiang (Wenzhou)	Sichuan (Emei), other records*