Skip to main content
NCBI home page
Insects logoLink to Insects
. 2025 Sep 17;16(9):974. doi: 10.3390/insects16090974

A Review of the Genus Homidia (Collembola, Entomobryidae) in China Informed by COI DNA Barcoding, with the Description of Three New Species †

Xiaowei Qian 1, Yu Fu 1, Yitong Ma 1,*
Editor: Markus Friedrich1
PMCID: PMC12470357  PMID: 41009153

Abstract

Simple Summary

The family Entomobryidae Tömösvary, 1882, is the largest family in Collembola, with around 2500 species in the world. It is characterised by the reduced prothorax, long antennae and furcula, and 4th abdominal segment much longer than 3rd. The genus Homidia, belonging to Entomobryidae, is mainly distributed in China. To date, 60 species of Homidia have been reported from China and account for approximately 71% of all known species of the genus. Here, the sequences of COI for ten Homidia species are provided, a neighbour-joining tree of Homidia is presented, three new species are described from Chongqing, China, and the taxonomic statuses of some species are discussed.

Abstract

The genus Homidia contains 84 species of which 60 have been reported from China. The sequence of COI for ten Homidia species are provided and a neighbour-joining tree is presented. Three new species of Homidia are described from Chongqing Municipality, China. Homidia wuxiensis sp. nov. is characterised by its colour pattern and chaetotaxy of Abd. IV; Homidia pseudochroma sp. nov. by some expanded post-labial chaetae and chaetotaxy of dorsal head and Abd. II–IV and Homidia yangi sp. nov. by its colour pattern. Based on similarities in COI sequences and morphology, we designate Homidia linhaiensis (Shi, Pan & Qi), as a junior synonym of Homidia tiantaiensis (Chen & Li).

Keywords: chaetotaxy, Chongqing, molecular marker, springtails, new species

1. Introduction

The genus Homidia was established as a subgenus of Entomobrya by Börner based on the presence of the inner spines at the base of the dens [1]. Denis considered this characteristic significant enough to raise Homidia to a generic level [2]. The genus is also characterised by the presence of a row of macrochaetae in eyebrow-like formation on the anterior part of 4th abdominal segment, a bidentate mucro with the subapical tooth much larger than the apical and the absence of scales [3].

To date, 84 species of the genus Homidia have been described worldwide and 60 species of them have been reported from China (Table 1) [4].

Table 1.

List of Homidia species from China *.

Anhui Province (4) Guangxi Zhuang Autonomous Region (7) Jilin Province (6) Shanxi Province (1)
H. anhuiensis Li & Chen, 1997 H. guangxiensis Zhou, Huang & Ma, 2024 H. hjesanica Szeptycki, 1973 H. sauteri (Börner, 1909)
H. qimenensis Yi & Chen, 1999 H. huapingensis Zhou, Huang & Ma, 2024 H. koreana Lee & Lee, 1981
H. socia Denis, 1929 H. longiantenna Zhou, Huang & Ma, 2024 H. phjongjangica Szeptycki, 1973 Yunnan Province (3)
H. wanensis Pan & Ma, 2021 H. oligoseta Zhou, Huang & Ma, 2024 H. similis Szeptycki, 1973 H. cingula (Börner, 1906)
H. qimenensis Yi & Chen, 1999 H. socia Denis, 1929 H. sauteri (Börner, 1909)
Beijing Municipality (1) H. sichuanensis Jia, Zhang & Jordana, 2010 H. speciosa Szeptycki, 1973 H. sinensis Denis, 1929
H. sinensis Denis, 1929 H. socia Denis, 1929
Guizhou Province (4) Zhejiang Province (22)
Fujian Province (7) Hubei Province (1) H. nigrifascia Ma & Pan, 2017 H. formosana Uchida, 1943
H. apigmenta Shi, Pan & Zhang, 2010 H. ziguiensis Jia, Chen & Christiansen, 2003 H. obliquistria Ma & Pan, 2017 H. hangzhouensis Pan & Ma, 2021
H. pseudosinensis Shi & Pan, 2012 H. qianensis Jing & Ma, 2023 H. hexaseta Pan, Shi & Zhang, 2011
H. qimenensis Yi & Chen, 1999 Hunan Province (1) H. sichuanensis Jia, Zhang & Jordana, 2010 H. jordanai Pan, Shi & Zhang, 2011
H. similis Szeptycki, 1973 H. polyseta Chen, 1998 H. laha (Christiansen & Bellinger, 1992)
H. sinensis Denis, 1929 H. latifolia Chen & Li, 1999
H. socia Denis, 1929 Jiangsu Province (5) Sichuan Province (2) H. linhaiensis Shi, Pan & Qi, 2009
H. transitoria Denis, 1929 H. fascia Wang & Chen, 2001 H. emeiensis Jia, Chen & Christiansen, 2004 H. phjongjangica Szeptycki, 1973
H. pentachaeta Li & Christiansen, 1997 H. sichuanensis Jia, Zhang & Jordana, 2010 H. pseudozhangi Jing & Ma, 2023
Gansu Province (1) H. pseudofascia Pan, Zhang & Li, 2015 H. qimenensis Yi & Chen, 1999
H. maijiensis Zhou & Ma, 2022 H. qimenensis Yi & Chen, 1999 Taiwan Province (6) H. quadrimaculata Pan, 2015
H. socia Denis, 1929 H. formosana Uchida, 1943 H. quadriseta Pan, 2018
Guangdong Province (5) H. linhaiensis Shi, Pan & Qi, 2009 H. sauteri (Börner, 1909)
H. chroma Pan & Yang, 2019 H. nigrocephala Uchida, 1943 H. similis Szeptycki, 1973
H. dianbaiensis (Lin, 1985) Jiangxi Province (7) H. sauteri (Börner, 1909) H. sinensis Denis, 1929
H. huizhouensis Zhou & Ma, 2022 H. acuta Jing & Ma, 2022 H. socia Denis, 1929 H. socia Denis, 1929
H. leniseta Pan & Yang, 2019 H. changensis Jing & Ma, 2022 H. taibaiensis Yuan & Pan, 2013 H. tiantaiensis Chen & Lin, 1998
H. sichuanensis Jia, Zhang & Jordana, 2010 H. hexchaeta Zhou & Ma, 2022 H. triangulimacula Pan & Shi, 2015
H. leei Chen & Li, 1997 Xizang Autonomous Region (4) H. unichaeta Pan, Shi & Zhang, 2010
Shaanxi Province (3) H. linhaiensis Shi, Pan & Qi, 2009 H. breviseta Pan, 2022 H. xianjuensis Wu & Pan, 2016
H. huashanensis Jia, Chen & Christiansen, 2005 H. socia Denis, 1929 H. sichuanensis Jia, Zhang & Jordana, 2010 H. yandangensis Pan, 2015
H. mediofascia Shi, Pan & Bai, 2009 H. pseudozhangi Jing & Ma, 2023 H. sinensis Denis, 1929 H. zhangi Pan & Shi, 2012
H. taibaiensis Yuan & Pan, 2013 H. tibetensis Chen & Zhong, 1998
Open in a new tab

* The bolds representing province or autonomous region of China.

Sixteen species of Homidia have been reported from the Korean Peninsula, fourteen from Japan, seven from Vietnam, six from the United States of America, two from India and Thailand, one from Bangladesh, Indonesia, Malaya and Singapore (Table 2).

Table 2.

List of Homidia species from other regions except China *.

Korean Peninsula (16) Japan (14) Vietnam (7)
H. chosonica Szeptycki, 1973 H. allospila (Börner, 1909) H. glassa Nguyen, 2001
H. flavonigra Szeptycki, 1973 H. amethystinoides Jordana & Baquero, 2010 H. lakhanpurensis Baquero & Jordana, 2015
H. grisea Lee & Lee, 1981 H. chrysothrix Yosii, 1942 H. multidentata Nguyen, 2005
H. heugsanica Lee & Park, 1984 H. cingula (Börner, 1906) H. sinensis Denis, 1929
H. hjesanica Szeptycki, 1973 H. fujiyamai Uchida, 1954 H. socia Denis, 1929
H. koreana Lee & Lee, 1981 H. munda Yosii, 1956 H. subcingula Denis, 1948
H. mediaseta Lee & Lee, 1981 H. nigrocephala Uchida, 1943 H. unichaeta Pan, Shi & Zhang, 2010
H. minuta Kim & Lee, 1995 H. rosannae Jordana &
Baquero, 2010
H. munda Yosii, 1956 H. sauteri (Börner, 1909) The United States of America (6)
H. nigra Lee & Lee, 1981 H. sinensis Denis, 1929 H. haikea (Christiansen & Bellinger, 1992)
H. phjongjangica Szeptycki, 1973 H. socia Denis, 1929 H. hihiu (Christiansen & Bellinger, 1992)
H. pseudoformosana Kang & Park, 2012 H. sotoi Jordana & Baquero, 2010 H. insularis (Carpenter, 1904)
H. pseudokoreana Lee & Park, 2024 H. subcingula Denis, 1948 H. laha (Christiansen & Bellinger, 1992)
H. sauteri (Börner, 1909) H. yoshiii Jordana & Baquero,
2010		 H. sauteri (Börner, 1909)
H. similis Szeptycki, 1973 H. socia Denis, 1929
H. speciosa Szeptycki, 1973
India (2) Thailand (2)
Bangladesh, Indonesia, Malaya, Singapore (1) H. cingula (Börner, 1906) H. cingula (Börner, 1906)
H. cingula (Börner, 1906) H. lakhanpurensis Baquero & Jordana 2015 H. subcingula Denis, 1948
Open in a new tab

* The bolds representing country or region.

The colour pattern is an important element in the taxonomy of the genus and it is intraspecifically stable but it varies between different species in general. In fact, some species were named based on the colour pattern. The chaetotaxy of dorsal body is another important character, but it is interspecifically conservative. Other elements, such as the labial and post-labial chaetotaxy, tenent hair and ventral tube, are also useful in the taxonomy of Homidia. With the development of molecular methods, some molecular markers, such as COI, are used in its taxonomy. The COI sequences for 25 Homidia species are available in GenBank. Here, we provide the COI sequences for ten additional species of Homidia and present an expanded neighbour-joining tree of available COI sequences. Some species are discussed and three new species are described from Chongqing (China).

2. Material and Methods

2.1. Taxon Sampling and Specimens Examinations

Specimens were collected with an aspirator from leaf litter and stored in 99% alcohol. They were mounted on glass slides in Marc André II solution and were studied with a Leica DM2500 phase contrast microscope (Wetzlar, Hessen, Germany). Photographs were taken using a Leica DFC300 FX digital camera (Wetzlar, Hessen, Germany) mounted on the microscope and edited with Photoshop CS2 9.0 version (Adobe Inc., San Jose, CA, USA).

The nomenclature of the dorsal macrochaetotaxy of the head and interocular chaetae follows Jordana and Baquero (2005) and Mari-Mutt (1979, 1986) [5,6,7]. Labial chaetae are designated following Gisin (1964) [8]. Labral chaetae follows Szeptycki (1973) and trunk dorsal chaetotaxy follows Szeptycki (1979) [9,10].

The abbreviations used are as follows. Ant.—antennal segment(s); Th.—thoracic segment(s); Abd.—abdominal segment(s); mac—macrochaeta(e); mes—mesochaeta(e); ms—specialised microchaeta(e); sens—specialised ordinary chaeta(e).

2.2. DNA Extraction and Amplification

DNA was extracted by using an Ezup Column Animal Genomic DNA Purification Kit (Sangon Biotech, Shanghai, China) following the manufacturer’s standard protocols. Amplification of a 658 bp fragment of the mitochondrial COI gene was carried out using a Prime Thermal Cycler (TECHNE, Bibby Scientific Limited, Stone, Staffordshire, UK), performed in 25 μL volumes using Premix Taq polymerase system (Takara Bio, Otsu, Shiga, Japan). The primers and polymerase chain reaction (PCR) programs followed Greenslade et al. (2011) [11]. All PCR products were checked using a 1% agarose gel electrophoresis. Successful products were purified and sequenced on an ABI 3730XL DNA Analyser (Applied Biosystem, Foster City, CA, USA). All experiments were completed by Shenggong (Shanghai, China). The GenBank accession numbers are provided in Table 3.

Table 3.

Species information and COI GenBank accession numbers.

Species Voucher GenBank Data
H. acuta Jing & Ma, 2022 2902 PP379473 GenBank
H. anhuiensis Li & Chen, 1997 AHLA_1 KJ873825 GenBank
H. changensis Jing & Ma, 2022 1243-1 PV891625 This study
H. cingula (Börner, 1906) 14YN2_1 KP699612 GenBank
H. cingula (Börner, 1906) 14YN3-2 KP699621 GenBank
H. cingula (Börner, 1906) JAVA05CV03 KJ923193 GenBank
H. fascia Wang & Chen, 2001 4399_1 KJ486274 GenBank
H. formosana Uchida, 1943 HNCS KJ873769 GenBank
H. grisea Lee & Lee, 1981 HG_117-1_2 OQ857813 GenBank
H. guangxiensis Zhou, Huang & Ma, 2024 8302 PP379462 GenBank
H. huapingensis Zhou, Huang & Ma, 2024 7402 PP379451 GenBank
H. koreana Lee & Lee, 1981 HK_111-1 OQ372969 GenBank
H. laha (Christiansen & Bellinger, 1992) 14YN27_1 KP699613 GenBank
H. latifolia Chen & Li, 1999 HNCS_2 KJ781774 GenBank
H. linhaiensis Shi, Pan & Qi, 2009 1241-1 PV891626 This study
H. linhaiensis Shi, Pan & Qi, 2009 m1246-1 PV891627 This study
H. longiantenna Zhou, Huang & Ma, 2024 8103 PP379458 GenBank
H. mediaseta Lee & Lee, 1981 HM_114-1 OQ372982 GenBank
H. munda Yosii, 1956 HMU_116_3 OQ857816 GenBank
H. nigra Lee & Lee, 1981 HNG_131 OQ857819 GenBank
H. nigrifascia Ma & Pan, 2017 m1128-1 PV891628 This study
H. nigrifascia Ma & Pan, 2017 m1128-2 PV891629 This study
H. nigrifascia Ma & Pan, 2017 m1149-3 PV891630 This study
H. nigrocephala Uchida, 1943 HNCH_122-2 OQ857821 GenBank
H. obliquistria Ma & Pan, 2017 m1246-2 PV891631 This study
H. oligoseta Zhou, Huang & Ma, 2024 8306 PP379465 GenBank
H. phjongjangica Szeptycki, 1973 XB_1 KJ873666 GenBank
H. pseudochroma sp. nov. m1306-11 PV891613 This study
H. pseudochroma sp. nov. m1306-12 PV891614 This study
H. pseudochroma sp. nov. m1306-13 PV891615 This study
H. pseudosinensis Shi & Pan, 2012 FJFZ_1 KJ873868 GenBank
H. pseudozhangi Jing & Ma, 2023 1235-1 PV891632 This study
H. sauteri (Börner, 1906) 12-19-Hsa-1 KM610127 GenBank
H. sichuanensis Jia, Zhang & Jordana, 2010 1 KJ873647 GenBank
H. similis Szeptycki, 1973 HS_5-3_167 OQ857825 GenBank
H. sinensis Denis, 1929 4017A11 KJ923203 GenBank
H. socia Denis, 1929 HBHS_1 KJ873798 GenBank
H. taibaiensis Yuan & Pan, 2013 m1306-14 PV891633 This study
H. taibaiensis Yuan & Pan, 2013 m1318-1 PV891634 This study
H. taibaiensis Yuan & Pan, 2013 m1306-19 PV891635 This study
H. taibaiensis Yuan & Pan, 2013 m1306-20 PV891636 This study
H. tiantaiensis Chen & Lin, 1998 AHLA_1 KJ873814 GenBank
H. wanensis Pan & Ma, 2021 m1189-2 PV891637 This study
H. wuxiensis sp. nov. m1317-5 PV891616 This study
H. wuxiensis sp. nov. m1317-6 PV891617 This study
H. wuxiensis sp. nov. m1317-7 PV891618 This study
H. yangi sp. nov. m1317-2 PV891619 This study
H. yangi sp. nov. m1317-3 PV891620 This study
H. yangi sp. nov. m1317-4 PV891621 This study
H. yangi sp. nov. m1321-25 PV891622 This study
H. yangi sp. nov. m1321-26 PV891623 This study
H. yangi sp. nov. m1321-27 PV891624 This study
Open in a new tab

2.3. Neighbour-Joining Tree

DNA sequences were assembled using Sequencher 4.5 (Gene Codes Corp., Ann Arbor, MI, USA) and then deposited in GenBank. Sequences were aligned using ClustalW implemented in MEGA 5.1 (Tamura et al., 2011) [12] with default settings. Pairwise genetic distances were analysed in MEGA 5.1 under the Kimura 2-parameter (K2-P) model (Kimura, 1980) [13]. The neighbour-joining tree was presented in the following discussion.

3. Results

3.1. Taxonomy

Class Collembola Lubbock, 1873 [14].

Order Entomobryomorpha Börner, 1913 [15].

Family Entomobryidae Schäffer [16].

Genus Homidia Börner, 1906 [1].

Type species: Homidia cingula (Börner, 1906: 174) [1].

3.1.1. Homidia wuxiensis sp. nov.

Figure 1, Figure 2, Figure 3, Figure 4, Figure 5 and Figure 6, Table 4.

Figure 1.

Figure 1

Open in a new tab

Habitus of Homidia wuxiensis sp. nov. (lateral view). Scale bar: 500 μm.

Figure 2.

Figure 2

Open in a new tab

Homidia wuxiensis sp. nov. (A) apex of Ant. IV (dorsal view); (B) distal Ant. III (ventral view); (C) distal Ant. II (ventral view) (solid rod may absent); (D) prelabrum and labrum; (E) dorsal head (right side) (solid circle may absent); (F) maxillary palp and outer lobe (right side); (G) labial palp (right side); (H) labial and post-labial chaetotaxy (right side). Scale bars: 20 μm.

Figure 3.

Figure 3

Open in a new tab

Homidia wuxiensis sp. nov. (A) chaetotaxy of Th. II–III (right side); (B–D) coxal chaetotaxy of fore, middle and hind leg; (E) trochanteral organ; (F) hind foot complex (lateral view); (G) SEM photomicrograph of hind foot complex (lateral view). Scale bars: (A) 50 μm; (B–G) 20 μm.

Figure 4.

Figure 4

Open in a new tab

Chaetotaxy of Abd. I–III of Homidia wuxiensis sp. nov. (right side). Scale bar: 50 μm.

Figure 5.

Figure 5

Open in a new tab

Homidia wuxiensis sp. nov. (A) chaetotaxy of Abd. IV (right side); (B) central chaetotaxy of Abd. IV posteriorly; (C) chaetotaxy of Abd. V (right side). Scale bars: (A,B) 50 μm; (C) 20 μm.

Figure 6.

Figure 6

Open in a new tab

Homidia wuxiensis sp. nov. (A) anterior face of ventral tube; (B) smooth chaetae of posterior face of ventral tube apically; (C) lateral flap of ventral tube; (D) manubrial plaque (dorsal view); (E) ventro-apical part of manubrium; (F) proximal and median section of dens (circles also representing spines); (G) mucro (lateral view). Scale bars: 20 μm.

Type material

Holotype: Female on slide, China, Chongqing Municipality, Wuxi County, the Yintiaoling National Nature Reserve, the Hongqi Protection Station, 31°30′33″ N, 109°49′10″ E, 1129.10 m a.s.l., 21 July 2024, Yitong Ma leg. Paratypes: one female on slide, same collection data as holotype; three females on slides, China, Wuxi County, the Yintiaoling National Nature Reserve, the Lanying Protection Station, Xi’an Village, 31°24′01″ N, 109°51′51″ E, 1625.63 m a.s.l., 26 July 2024, Yitong Ma leg.

Etymology

Named after its locality: Wuxi County.

Diagnosis

Th. II–III brown; brown pigment present at basal parts of Ant. III–IV; labial base with MReL1L2, e smooth, other ciliate; Ant. IV with 19–25 anterior and 13–20 posterior mac; dens with 37–63 smooth inner spines.

Description

Measurement: Body length up to 3.28 mm.

Colour: Ground colour pale yellow; eye patches dark blue; Th. II–III brown; brown pigment present at basal parts of Ant. III–IV, medial and posterior parts of Abd. IV; anterior part of head, coxae of middle and hind legs, tibiotarsi of fore and middle legs with a little scattered brown pigment (Figure 1).

Head: Antenna not annulated and 1.05–1.10 times length of body. Ratio of Ant. I–IV as 1.00/1.25–1.29/1.00–1.10/2.00. Distal part of Ant. IV with many sensory chaetae and normal ciliate chaetae, apical bulb bilobed (Figure 2A). Ant. III sense organ with two rods, two spiny guard sensilla, smooth blunt sens and ciliated chaetae (Figure 2B). Ant. II with 3–4 rods apically (Figure 2C). Prelabral and labral chaetae as 4/5, 5, 4, all smooth, a2 and b2 slightly shorter than middle ones, labral papillae not clearly seen (Figure 2D). Eyes 8 + 8, G and H smaller than others, interocular chaetae as p, r, t mes. Dorsal chaetotaxy of head with 5–6 antennal (An), five median (M) and eight sutural (S) mac (Figure 2E). Basal chaeta on maxillary outer lobe slightly thicker than apical one; sublobal plate with three smooth chaetae-like processes (Figure 2F). Lateral process (l. p.) of labial palp E differentiated with tip not reaching apex of papilla E (Figure 2G). Labial base with MReL1L2, e smooth, other ciliate, R 0.60–0.79 length of M (Figure 2H).

Thorax: Tergal ms formula on Th. II–Abd. V as 1, 0/1, 0, 1, 0, 0, sens as 2, 2/1, 2, 2, 2, 3 (Figure 3A, Figure 4 and Figure 5A,C). Th. II with 5–8 medio-medial (m1, m2, m2i, m2i2, 1–4 unnamed mac), three medio-sublateral (m4, m4i, m4p), 46–50 posterior mac. Th. III with 43–49 mac (Figure 3A). Coxal macrochaetal formula as 3/4 + 1, 3/4 + 2 (Figure 3B–D). Trochanteral organ with 86–111 smooth chaetae (Figure 3E). Tenent hair clavate, 0.86–1.00 length of inner edge of unguis; unguis with 3–4 inner teeth, basal pair located at 0.42–0.44 distance from base of inner edge of unguis, distal unpaired teeth at 0.67–0.68 and 0.85–0.86 distance from base, respectively, most distal one very faint and usually absent; unguiculus lanceolate, outer edge slightly serrate (Figure 3F,G).

Abdomen: Range of Abd. IV length as 7.67–7.86 times as dorsal axial length of Abd. III. Abd. I with 11 (a1a, a1–3, m2i, m2–4, m4i, m4p and a5 mac). Abd. II with six (a2, a3, m3, m3e, m3ea, m3ep) central, one (m5) lateral mac. Abd. III with two (a2, m3) central, four (am6, pm6, m7a, p6) lateral mac (Figure 4). Abd. IV with two normal sens, 19–25 anterior, 13–25 posterior and 19–27 lateral mac or mes (Figure 5A,B). Abd. V with three sens (Figure 5C). Anterior face of ventral tube with 58–77 ciliate chaetae, 3+3 of them as mac, line connecting proximal (Pr) and external-distal (Ed) mac oblique to median furrow (Figure 6A); posterior face with 4–5 smooth chaetae apically (Figure 6B); lateral flap with 6–10 smooth and 26–33 ciliate chaetae (Figure 6C). Manubrial plate dorsally with 13–16 ciliate mac and three pseudopores (Figure 6D); ventrally with 39–48 ciliate chaetae on each side (Figure 6E). Dens with 37–63 smooth inner spines (Figure 6F). Mucro bidentate with subapical tooth larger than apical one; tip of basal spine reaching apex of subapical tooth; distal smooth section of dens almost equal to mucro in length (Figure 6G).

Remarks

The new species is characterised by its colour pattern and chaetotaxy of Abd. IV and is mostly similar to the species H. anhuiensis Li & Chen, 1997 [17] and H. speciosa Szeptycki, 1973 [9], but there are some differences between them, such as the colour pattern on head, labial chaetotaxy, number of central mac on Abd. IV posteriorly and other characters. The detailed characteristic comparisons are listed in Table 4.

Table 4.

Main differences among the new species and similar species of Homidia.

Characters H. wuxiensis sp. nov. H. anhuiensis H. speciosa
Colour pattern on head yellow mainly black entirely black entirely
Labial chaetotaxy MReL1L2 MREL1L2 MReL1L2
Central mac on Abd. IV anteriorly 19–25 9 10–11 *
Central mac or mes on Abd. IV posteriorly 13–20 6–7 5–6
Dental spines 37–63 12–21 28–43
Open in a new tab

* based on Zhou & Ma, 2023 [18].

3.1.2. Homidia pseudochroma sp. nov.

Figure 7, Figure 8, Figure 9, Figure 10, Figure 11 and Figure 12, Table 5.

Figure 7.

Figure 7

Open in a new tab

Habitus of Homidia pseudochroma sp. nov. (A) dorsal view.; (B) lateral view. Scale bars: 500 μm.

Figure 8.

Figure 8

Open in a new tab

Homidia pseudochroma sp. nov. (A) apex of Ant. IV (dorsal view); (B) SEM photomicrograph of apex of Ant. IV (lateral view); (C) distal Ant. III (ventral view); (D) distal Ant. II (ventral view); (E) SEM photomicrograph of distal Ant. II (lateral view, black arrows showing rods); (F) prelabrum and labrum; (G) dorsal head; (H,I) SEM photomicrograph of dorsal head partially ((H) right side; (I) left side); Scale bars: 20 μm.

Figure 9.

Figure 9

Open in a new tab

Homidia pseudochroma sp. nov. (A) maxillary palp and outer lobe (right side); (B) labial palp (right side); (C) labial and post-labial chaetotaxy (right side). Scale bars: 20 μm.

Figure 10.

Figure 10

Open in a new tab

Homidia pseudochroma sp. nov. (A) chaetotaxy of Th. II–III (right side); (B–D) coxal chaetotaxy of fore, middle and hind leg; (E) trochanteral organ; (F,G) SEM photomicrograph of hind foot complex (lateral view). Scale bars: (A) 50 μm; (B–G) 20 μm.

Figure 11.

Figure 11

Open in a new tab

Chaetotaxy of Abd. I–III of Homidia pseudochroma sp. nov. (right side). Scale bar: 50 μm.

Figure 12.

Figure 12

Open in a new tab

Homidia pseudochroma sp. nov. (A) chaetotaxy of Abd. IV (right side); (B) central chaetotaxy of Abd. IV posteriorly; (C) chaetotaxy of Abd. V. Scale bars: (A,B) 50 μm; (C) 20 μm.

Table 5.

Main differences among the new species and similar species of Homidia.

Characters H. pseudochroma sp. nov. H. chroma H. obliquistria H. pentachaeta
S mac on head 10 8 8 8
Mac on Abd. I 12 11 11–12 10
M3ei mac on Abd. II present absent absent absent
Central mac on Abd. III 3 2 2 3
Lateral mac on Abd. III 5 4 4 5
Anterior mac or mes on Abd. IV 21–22 9–12 15–24 10–13
Central mac or mes on Abd. IV 14–18 6 13–33 12–14
Labial chaetotaxy MM1ReL1L2 MRel1L2 MM1ReL1L2 MRel1L2
Expanded post-labial chaetae present absent present absent
A medial longitudinal strip on Th. II–III absent absent present absent
Open in a new tab

Type material

Holotype: Female on slide, China, Chongqing Municipality, Wuxi County, the Yintiaoling National Nature Reserve, the Hongqi Protection Station, 31°30′33″ N, 109°49′10″ E, 1129.10 m a.s.l., 21 July 2024, Yitong Ma leg. Paratypes: Three females on slides, same collection data as holotype.

Etymology

Named after its similarity in colour pattern to H. chroma Pan & Yang.

Diagnosis

Ant. II–IV and Abd. V brown; posterior margin of Abd. III and medial and posterior parts of Abd. IV with narrow transverse chrome to brown pigmented bands; labial base with MM1ReL1L2, M1 rarely duplicate, e smooth, other ciliate, G1–2, X3 and H2 slightly expanded, G3–4, X and H3–4 strongly expanded in post-labial area; dens with 46–58 smooth inner spines.

Description

Measurement: Body length up to 3.11 mm.

Colour: Ground colour pale white; eye patches dark blue; Ant. II–IV and Abd. V brown; posterior margin of Abd. III and medial and posterior parts of Abd. IV with narrow transverse chrome to brown pigmented bands; little scattered brown or purple pigment present on tibiotarsi and lateral part of Th. II–Abd. II (Figure 7).

Head: Antenna not annulated and 0.48–0.59 times length of body. Ratio of Ant. I–IV as 1.00/1.35–1.59/1.00–1.33/1.77–2.27. Distal part of Ant. IV with many sensory chaetae and normal ciliate chaetae, apical bulb bilobed (Figure 8A,B). Ant. III sense organ with two rods, two spiny guard sensilla, smooth blunt sens and ciliated chaetae (Figure 8C). Ant. II with 3–4 rods apically (Figure 8D,E). Prelabral and labral chaetae as 4/5, 5, 4, all smooth, a2 and b2 slightly shorter than middle ones, labral papillae not clearly seen (Figure 8F). Eyes 8 + 8, G and H smaller than others, interocular chaetae as p, r, t mes. Dorsal chaetotaxy of head with four mac in antennal (An) area, five mac and one mes in median (M) area and 10 mac and 0–2 mes in sutural (S) area (Figure 8G–I). Basal chaeta on maxillary outer lobe slightly thicker than apical one; sublobal plate with three smooth chaetae-like processes (Figure 9A). Lateral process (l. p.) of labial palp E differentiated with tip almost reaching apex of papilla E (Figure 9B). Labial base with MM1ReL1L2, M1 rarely duplicate, e smooth, other ciliate, R 0.56–0.64 length of M; G1–2, X3 and H2 slightly expanded, G3–4, X and H3–4 strongly expanded in post-labial area (Figure 9C).

Thorax: Tergal ms formula on Th. II–Abd. V as 1, 0/1, 0, 1, 0, 0, sens as 2, 2/1, 2, 2, 2, 3 (Figure 10A, Figure 11 and Figure 12A,C). Th. II with four medio-medial (m1, m2, m2i, m2i2) mac, three medio-sublateral (m4, m4i, m4p), 36–41 posterior mac. Th. III with 54–57 mac (Figure 10A). Coxal macrochaetal formula as 3/4 + 1, 3/4 + 2 (Figure 10B–D). Trochanteral organ with 46–68 smooth chaetae (Figure 10E). Tenent hair clavate, 0.88–1.02 length of inner edge of unguis; unguis with 3–4 inner teeth, basal pair located at 0.39–0.42 distance from base of inner edge of unguis, distal unpaired teeth at 0.65–0.69 and 0.87–0.88 distance from base, respectively, most distal one very faint and usually absent; unguiculus lanceolate, outer edge slightly serrate (Figure 10F,G).

Abdomen: Range of Abd. IV length as 8.26–10.8 times as dorsal axial length of Abd. III. Abd. I with 12 (a1a, a1–3, m2i, m2–5, m4i, m4p, a5) mac. Abd. II with seven (a2, a3, m3, m3e, m3ea, m3ep, me3i) central, one (m5) lateral mac. Abd. III with two (a2, m3) central, five (am6, pm6, m7a, p6, p7) lateral mac (Figure 11). Abd. IV with two normal sens, 21–22 anterior, 14–18 (rarely 23) posterior and 32–37 lateral mac or mes (Figure 12A,B). Abd. V with three sens (Figure 12C). Anterior face of ventral tube with 40–42 ciliate chaetae, 3+3 of them as mac, line connecting proximal (Pr) and external-distal (Ed) mac oblique to median furrow (Figure 13A); posterior face with 5–7 smooth chaetae apically (Figure 13B); lateral flap with about seven smooth and 20 ciliate chaetae (Figure 13C). Manubrial plate dorsally with 12–14 ciliate mac and three pseudopores (Figure 13D); ventrally with 38–42 ciliate chaetae on each side (Figure 13E). Dens with 46–58 smooth inner spines (Figure 13F). Mucro bidentate with subapical tooth larger than apical one; tip of basal spine reaching apex of subapical tooth; distal smooth section of dens almost equal to mucro in length.

Figure 13.

Figure 13

Open in a new tab

Homidia pseudochroma sp. nov. (A) anterior face of ventral tube; (B) smooth chaetae of posterior face of ventral tube apically; (C) lateral flap of ventral tube; (D) manubrial plaque (dorsal view); (E) ventro-apical part of manubrium; (F) proximal and median section of dens (circles also representing spines). Scale bars: 20 μm.

Remarks

The new species is characterised by some expanded post-labial chaetae, the dorsal chaetotaxy of the head and Abd. II–IV, such as m3ei mac on Abd. II and p7 mac on Abd. IV. It is similar to H. pentachaeta Li & Christiansen, 1997 in the chaetotaxy of Abd. III, but the colour pattern, dorsal head chaetotaxy and other characters can be used to separate them [19]. It is also similar to H. chroma Pan & Yang, 2019 and H. obliquistria Ma & Pan, 2017 in the colour pattern, but there are many differences between them, such as the chaetotaxy of head and Abd. II–IV, shape of chaetae of post-labial area and other characters [20,21]. The detailed characteristic comparisons are listed in Table 5.

3.1.3. Homidia yangi sp. nov.

Figure 14, Figure 15, Figure 16, Figure 17, Figure 18 and Figure 19, Table 6.

Figure 14.

Figure 14

Open in a new tab

Habitus of Homidia yangi sp. nov. ((A) dorsal view; (B) lateral view; (C) dorsal view). Scale bars: 500 μm.

Figure 15.

Figure 15

Open in a new tab

Homidia yangi sp. nov. (A) apex of Ant. IV (dorsal view); (B) distal Ant. III (ventral view); (C) distal Ant. II (ventral view); (D) prelabrum and labrum; (E) dorsal head (right side); (F) maxillary palp and outer lobe (right side); (G) labial palp (right side); (H) labial and post-labial chaetotaxy (right side). Scale bars: 20 μm.

Figure 16.

Figure 16

Open in a new tab

Homidia yangi sp. nov. (A) chaetotaxy of Th. II–III (right side); (B–D) coxal chaetotaxy of fore, middle and hind leg; (E) trochanteral organ; (F) hind foot complex (lateral view); (G) SEM photomicrograph of hind foot complex (lateral view). Scale bars: (A) 50 μm; (B–G) 20 μm.

Figure 17.

Figure 17

Open in a new tab

Chaetotaxy of Abd. I–III of Homidia yangi sp. nov. (right side). Scale bar: 50 μm.

Figure 18.

Figure 18

Open in a new tab

Chaetotaxy of Abd. IV of Homidia yangi sp. nov. (right side) Scale bar: 50 μm.

Figure 19.

Figure 19

Open in a new tab

Homidia yangi sp. nov. (A) chaetotaxy of Abd. V; (B) anterior face of ventral tube; (C) smooth chaetae of posterior face of ventral tube apically; (D) lateral flap of ventral tube; (E) manubrial plaque (dorsal view); (F) ventro-apical part of manubrium; (G) proximal and median section of dens (circles also representing spines); (H) mucro (lateral view); (I) SEM photomicrograph of mucro (lateral view). Scale bars: 20 μm.

Table 6.

Main differences among the new species and similar species of Homidia.

Characters H. yangi sp. nov. H. oligoseta H. quadriseta
A transverse brown band on Th. III present present absent
A transverse brown band on Abd. II absent present absent
Tenent hair clavate pointed clavate
Central mac on Abd. IV anteriorly 9 3–4 2
Central mac on Abd. IV posteriorly 6 4 (5) 3
Open in a new tab

Type material

Holotype: Female on slide, China, Chongqing Municipality, Wuxi County, the Yintiaoling National Nature Reserve, the Guanshan Protection Station, 31°32′14″ N, 109°41′53″ E, 2168.92 m a.s.l. 28 July 2024, Yitong Ma leg. Paratypes: two females on slides, same collection data as holotype.

Etymology

Named after Mr. Zhiming Yang, whose help is essential to the research of the biological diversity of the Yintiaoling National Nature Reserve.

Diagnosis

Th. III and Abd. III brown; Abd. IV almost brown entirely; Labial base with MReL1L2, e smooth, other ciliate, L1 rarely smooth; Abd. IV with nine (rarely 12) anterior and six posterior mac; dens with about 36 smooth inner spines.

Description

Measurement: Body length up to 2.35 mm.

Colour: Ground colour pale yellow; eye patches dark blue; Ant. I–IV, Th. III and Abd. III brown; Abd. IV almost brown entirely; head, legs, Th. II, Abd. I–II and V with brown pigment; scattered brown pigment present on ventral tube and manubrium (Figure 14A–C).

Head: Antenna not annulated and 0.67–0.77 times length of body. Ratio of Ant. I–IV as 1.00/1.24–1.67/1.04–1.33/2.00–2.87. Distal part of Ant. IV with many sensory chaetae and normal ciliate chaetae, apical bulb bilobed (Figure 15A). Ant. III sense organ with two rods, two spiny guard sensilla, smooth blunt sens and ciliated chaetae (Figure 15B). Ant. II with 3–4 rods apically (Figure 15C). Prelabral and labral chaetae as 4/5, 5, 4, all smooth, a2 and b2 slightly shorter than middle ones (Figure 15D). Eyes 8 + 8, G and H smaller than others, interocular chaetae as p, r, t mes. Dorsal chaetotaxy of head with four antennal (An), five median (M) and eight sutural (S) mac (Figure 15E). Basal chaeta on maxillary outer lobe slightly thicker than apical one; sublobal plate with three smooth chaetae-like processes (Figure 15F). Lateral process (l. p.) of labial palp E differentiated with tip not reaching apex of papilla E (Figure 15G). Labial base with MReL1L2, e smooth, other ciliate, L1 rarely smooth, R 0.64–0.69 length of M (Figure 15H).

Thorax: Tergal ms formula on Th. II–Abd. V as 1, 0/1, 0, 1, 0, 0, sens as 2, 2/1, 2, 2, 2, 3 (Figure 16A, Figure 17, Figure 18 and Figure 19A). Th. II with four medio-medial (m1, m2, m2i, m2i2) mac, three medio-sublateral (m4, m4i, m4p), 34–47 posterior mac. Th. III with 41–54 mac (Figure 16A). Coxal macrochaetal formula as 3/4 + 1, 3/4 + 2 (Figure 16B–D). Trochanteral organ with 86–94 smooth chaetae (Figure 16E). Tenent hair clavate, 0.90–1.11 length of inner edge of unguis; unguis with 3–4 inner teeth, basal pair located at 0.36–0.42 distance from base of inner edge of unguis, unpaired tooth at 0.65–0.68 and 0.86 distance from base, respectively, most distal one very faint and usually absent; unguiculus lanceolate, outer edge slightly serrate (Figure 16F,G).

Abdomen: Range of Abd. IV length as 4.43–6.04 times as dorsal axial length of Abd. III. Abd. I with 11 (a1a, a1–3, m2i, m2–4, m4i, m4p, a5) mac. Abd. II with six (a2, a3, m3, m3e, m3ea, m3ep) central, one (m5) lateral mac. Abd. III with two (a2, m3) central, four (am6, pm6, m7a, p6) lateral mac (Figure 17). Abd. IV with two normal sens, 9 (rarely 12) anterior, six posterior and 17–20 lateral mac or mes (Figure 18). Abd. V with three sens (Figure 19A). Anterior face of ventral tube with 27–30 ciliate chaetae, 3+3 of them as mac, line connecting proximal (Pr) and external-distal (Ed) mac oblique to median furrow (Figure 19B); posterior face with five smooth chaetae apically (Figure 19C); lateral flap with 13–19 smooth and 4–8 ciliate chaetae (Figure 19D). Manubrial plate dorsally with 10–13 ciliate mac and three pseudopores (Figure 19E); ventrally with 26–33 ciliate chaetae on each side (Figure 19F). Dens with about 36 smooth inner spines (Figure 19G). Mucro bidentate with subapical tooth larger than apical one; tip of basal spine reaching apex of subapical tooth; distal smooth section of dens almost equal to mucro in length (Figure 19H,I).

Remarks

The new species can be distinguished from the other known species of genus Homidia by its colour pattern and it is similar to H. oligoseta Zhou, Huang & Ma, 2024 [22] and H. quadriseta Pan, 2018 [23] on the character. However, there are some differences between them in the chaetotaxy of Abd. IV and tenent hair. The detailed characteristic comparisons are listed in Table 6.

3.2. Neighbour-Joining Tree Analysis

Most sequenced individuals in the present study have a mean K2-P distance of COI sequences more than 14.0% (Figure 20, Table 7) and the number is greater than or comparable to the previous reported interspecific distances of 11.4% in the Tomocerus nigrus complex (Zhang et al., 2014) [24], 13.0% in Plutomurus (Barjadze et al., 2016) [25] and 16.2% in Coecobrya (Zhang et al., 2018) [26]. This indicates that the species delimitations are distinct among these species. However, the genetic distance between H. laha and H. sauteri is 0.0% and between H. linhaiensis and H. tiantaiensis is 0.3% (Table 7).

Figure 20.

Figure 20

Open in a new tab

Neighbour-joining tree (using the K2-P model) of Homidia species based on COI sequences.

Table 7.

The genetic distance (mean K2-P divergence) within and between species in the study *.

Species acu anh cha cin fas for gri gua hua kor lah lat lin lon med mun nia nig
acu
anh 28.7
cha 24.0 29.9
cin 22.3 28.2 18.9
fas 29.7 31.8 30.9 29.2
for 22.6 30.3 25.6 23.9 31.3
gri 28.9 34.8 20.3 22.5 35.8 30.5
gua 24.7 26.8 25.9 24.2 25.2 26.3 30.8
hua 26.5 34.2 29.5 27.8 35.2 23.1 34.4 30.2
kor 39.7 41.8 40.9 39.2 36.6 41.3 45.8 35.2 45.2
lah 30.8 32.9 32.0 30.3 25.1 32.4 36.9 26.3 36.3 37.7
lat 34.2 36.3 35.4 33.7 20.3 35.8 40.3 29.7 39.7 41.1 29.6
lin 30.5 32.6 31.7 30.0 27.4 32.1 36.6 26.0 36.0 31.4 28.5 31.9
lon 32.9 35.0 34.1 32.4 19.0 34.5 39.0 28.4 38.4 39.8 28.3 18.3 30.6
med 25.6 33.3 28.6 26.9 34.3 22.2 33.5 29.3 21.9 44.3 35.4 38.8 35.1 37.5
mun 37.1 39.2 38.3 36.6 34.0 38.7 43.2 32.6 42.6 19.6 35.1 38.5 28.8 37.2 41.7
nia 28.0 17.9 29.2 27.5 31.1 29.6 34.1 26.1 33.5 41.1 32.2 35.6 31.9 34.3 32.6 38.5
nig 26.8 21.3 28.0 26.3 29.9 28.4 32.9 24.9 32.3 39.9 31.0 34.4 30.7 33.1 31.4 37.3 20.6
nio 33.3 35.4 34.5 32.8 30.2 34.9 39.4 28.8 38.8 34.2 31.3 34.7 17.4 33.4 37.9 31.6 34.7 33.5
obl 33.9 36.0 35.1 33.4 20.0 35.5 40.0 29.4 39.4 40.8 29.3 14.3 31.6 18.0 38.5 38.2 35.3 34.1
oli 21.5 20.4 22.7 21.0 24.6 23.1 27.6 19.6 27.0 34.6 25.7 29.1 25.4 27.8 26.1 32.0 19.7 18.5
phj 30.3 32.4 31.5 29.8 27.2 31.9 36.4 25.8 35.8 34.0 28.3 31.7 24.8 30.4 34.9 31.4 31.7 30.5
psc 29.2 31.3 30.4 28.7 19.5 30.8 35.3 24.7 34.7 36.1 24.6 24.0 26.9 22.7 33.8 33.5 30.6 29.4
pss 31.2 33.3 32.4 30.7 28.1 32.8 37.3 26.7 36.7 34.9 29.2 32.6 25.7 31.3 35.8 32.3 32.6 31.4
psz 31.0 36.9 22.4 24.6 37.9 32.6 20.1 32.9 36.5 47.9 39.0 42.4 38.7 41.1 35.6 45.3 36.2 35.0
sau 30.8 32.9 32.0 30.3 25.1 32.4 36.9 26.3 36.3 37.7 0.0 29.6 28.5 28.3 35.4 35.1 32.2 31.0
sic 28.5 30.6 29.7 28.0 22.8 30.1 34.6 24.0 34.0 35.4 18.7 27.3 26.2 26.0 33.1 32.8 29.9 28.7
sim 28.1 30.2 29.3 27.6 25.0 29.7 34.2 23.6 33.6 31.8 26.1 29.5 22.6 28.2 32.7 29.2 29.5 28.3
sin 28.5 36.2 31.5 29.8 37.2 25.1 36.4 32.2 24.8 47.2 38.3 41.7 38.0 40.4 17.3 44.6 35.5 34.3
soc 28.2 30.3 29.4 27.7 25.1 29.8 34.3 23.7 33.7 26.7 26.2 29.6 19.9 28.3 32.8 24.1 29.6 28.4
tai 33.7 35.8 34.9 33.2 30.6 35.3 39.8 29.2 39.2 22.0 31.7 35.1 25.4 33.8 38.3 19.4 35.1 33.9
tia 29.5 31.6 30.7 29.0 26.4 31.1 35.6 25.0 35.0 30.4 27.5 30.9 0.3 29.6 34.1 27.8 30.9 29.7
wan 32.0 34.1 33.2 31.5 22.3 33.6 38.1 27.5 37.5 38.9 27.4 26.8 29.7 25.5 36.6 36.3 33.4 32.2
wux 36.2 38.3 37.4 35.7 33.1 37.8 42.3 31.7 41.7 39.9 34.2 37.6 30.7 36.3 40.8 37.3 37.6 36.4
yan 31.6 33.7 32.8 31.1 28.5 33.2 37.7 27.1 37.1 25.9 29.6 33.0 23.3 31.7 36.2 23.3 33.0 31.8
Species nio obl o li phj psc pss psz sau sic sim sin soc tai tia wan wux yan
nio
obl 34.4
oli 28.2 28.8
phj 27.6 31.4 25.2
psc 29.7 23.7 24.1 26.7
pss 28.5 32.3 26.1 24.5 27.6
psz 41.5 42.1 29.7 38.5 37.4 39.4
sau 31.3 29.3 25.7 28.3 24.6 29.2 39.0
sic 29.0 27.0 23.4 26.0 22.3 26.9 36.7 18.7
sim 25.4 29.2 23.0 17.6 24.5 22.3 36.3 26.1 23.8
sin 40.8 41.4 29.0 37.8 36.7 38.7 38.5 38.3 36.0 35.6
soc 22.7 29.3 23.1 22.5 24.6 23.4 36.4 26.2 23.9 20.3 35.7
tai 28.2 34.8 28.6 28.0 30.1 28.9 41.9 31.7 29.4 25.8 41.2 20.7
tia 17.4 30.6 24.4 23.8 25.9 24.7 37.7 27.5 25.2 21.6 37.0 18.9 24.4
wan 32.5 26.5 26.9 29.5 15.6 30.4 40.2 27.4 25.1 27.3 39.5 27.4 32.9 28.7
wux 33.5 37.3 31.1 29.5 32.6 22.8 44.4 34.2 31.9 27.3 43.7 28.4 33.9 29.7 35.4
yan 26.1 32.7 26.5 25.9 28.0 26.8 39.8 29.6 27.3 23.7 39.1 18.6 19.9 22.3 30.8 31.8
Open in a new tab

* The bolds are species abbreviations: acu, H. acuta; anh, H. anhuiensis; cha, changensis; cin, H. cingula; fas, H. fascia; for, H. formosana; gri, H. grisea; gua, H. guangxiensis; hua, H. huapingensis; kor, H. koreana; lah, H. laha; lat, H. latifolia; lin, H. linhaiensis; lon, H. longiantenna; med, H. mediaseta; mun, H. munda; nia, H. nigra; nig, H. nigrifascia; nio, H. nigrocephala; obl, H. obliquistria; oli, H. oligoseta; phj, H. phjongjangica; psc, H. pseudochroma sp. nov.; pss, H. pseudosinensis; psz, H. pseudozhangi; sau, H. sauteri; sic, H. sichuanensis; sim, H. similis; sin, H. sinensis; soc, H. socia; tai, H. taibaiensis; tia, H. tiantaiensis; wan, H. wanensis; wux, H. wuxiensis sp. nov.; yan, H. yangi sp. nov.

3.2.1. H. laha (Christiansen & Bellinger, 1992) and H. sauteri (Börner, 1906)

The genetic distance between H. laha and H. sauteri is 0.0, which indicates that they are the same species. The two species were discussed and synonymized by Ye et al. [27].

3.2.2. H. linhaiensis Shi, Pan & Qi, 2009 and H. tiantaiensis Chen & Lin, 1998

The genetic distance between H. linhaiensis and H. tiantaiensis is only 0.3%, which is much less than the accepted barcoding gap. The dorsal chaetotaxy of the two species are almost the same and both Abd. IV are with m2 mac, which is rarely present in Homidia [28,29]. Other morphological differences are very slight. The dental spines and smooth setae on lateral flap varies greatly intraspecifically (Table 8). After consulting with Dr. Zhixiang Pan, we think the species H. linhaiensis Shi, Pan & Qi, 2009 is a new synonym of H. tiantaiensis Chen & Lin, 1998.

Table 8.

Main comparison between H. linhaiensis and H. tiantaiensis.

Characters H. linhaiensis H. tiantaiensis
A pair of dark spots on Th. III present present
A pair of dark spots on Abd. III present absent or present
Labial chaetotaxy MRel1L2 MRel1L2
Dorsal chaetotaxy of head 7 An, 5 M, 9 S mac 5 An, 4 M, 9 S mac
Medio-medial mac on Th. II 4 4
Medio-sublateral mac on Th. II 4 3
Posterior mac on Th. II 26–29 35
Mac on Abd. I 10 (11) 10
Central mac on Abd. II 6 6
Central mac on Abd. III 2 2
Lateral mac on Abd. III 5 4
A2 mac on Abd. IV present present
Central mac on Abd. IV anteriorly 10–13 8–12
Central mac on Abd. IV posteriorly 10–16 13–16
Ungual inner teeth 4 3
Smooth setae on lateral flap 9 5
Dental spines 6–16 29–36
Open in a new tab

3.2.3. H. cingula (Börner, 1906) and H. nigrifascia Ma & Pan, 2017

H. cingula was redescribed by Zhang et al. [30] based on the specimens from South Sulawesi and Jawa Timur of Indonesia and Yunnan of China. Its colour pattern is almost the same with that of H. nigrifascia [21], reported from Guizhou, a province bordering Yunnan. Their different dorsal chaetotaxy on body and great genetic distance in COI (26.3%) show they are different species (Table 9).

Table 9.

Main differences between H. cingula and H. nigrifascia.

Characters H. cingula H. nigrifascia
Posterior mac on Th. II 23 37–45
Mac on Th. III 30 43–53
Mac on Abd. I 9 9–11
Central mac on Abd. II 5 6
Central mac on Abd. III 1 1–2
Central mac on Abd. IV posteriorly 4–5 6 (7)
Open in a new tab

4. Discussion

The genus Homidia is well represented and widespread in China, especially eastern China. Because of poor research, among 28 provinces or autonomous regions of China, there are no reports of Homidia from Hainan, Heilongjiang, Hebei, Henan, Inner Mongolia, Liaoning, Ningxia, Qinghai, Shandong and Xinjiang (municipalities and special administrative regions are not included for their small areas). During the biodiversity survey of the Yintiaoling National Nature Reserve of Chongqing Municipality in 2024, we found Homidia was the dominant entomobryid genus and the numbers of individual and species were the greatest. This is the first report of Homidia from Chongqing and it suggests that many more species of Homidia may remain to be found in China.

Acknowledgments

We thank the reviewers for their careful reading of our manuscript and their many insightful comments and suggestions, which have allowed us to produce a more robust manuscript.

Author Contributions

Conceptualization, methodology, investigation, X.Q. and Y.M.; drawings, Y.M.; SEM and Y.F.; writing, X.Q. and Y.M. All authors have read and agreed to the published version of the manuscript.

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflicts of interest.

Funding Statement

This research was funded by the Large Instrument Foundation of Nantong University, China (KFJN2475).

Footnotes

Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

References

  • 1.Börner C. Das system der Collembolen nebst Beschreibung neuer Collembolen des Hamburger Naturhistorischen Museums. Mitt. Nat. Hist. Mus. Hambg. 1906;23:147–188. [Google Scholar]
  • 2.Denis J.R. Notes sur les collemboles récoltés dans ses voyages par le Prof. F. Silvestri. I. Seconde note sur les collemboles d’Extrême-Orient. Boll. Zool. Gene. Agric. Portici. 1929;22:305–320. [Google Scholar]
  • 3.Pan Z.X., Shi S.D., Zhang F. A new species of Homidia (Collembola: Entomobryidae) from Wenzhou, with a key to the Homidia species from Zhejiang Province. Entomotaxonomia. 2011;33:161–167. [Google Scholar]
  • 4.Bellinger P.F., Christiansen K.A., Janssens F. Checklist of the Collembola of the World. 1996–2024. [(accessed on 10 September 2025)]. Available online: http://www.collembola.org.
  • 5.Jordana R., Baquero E. A proposal of characters for taxonomic identification of Entomobrya species (Collembola, Entomobryomorpha), with description of a new species. Abh. Ber. Naturkundemus Görlitz. 2005;76:117–134. [Google Scholar]
  • 6.Mari-Mutt J.A. A revision of the genus Dicranocentrus Schött (Insecta: Collembola: Entomobryidae) Agric. Exp. Stn. Bull. Puerto Rico. 1979;259:1–79. [Google Scholar]
  • 7.Mari-Mutt J.A. Puerto Rican species of Lepidocyrtus and Pseudosinella (Collembola: Entomobryidae) Caribb. J. Sci. 1986;22:1–48. [Google Scholar]
  • 8.Gisin H. European Collembola. VII. Rev. Suisse Zool. 1964;71:649–678. [Google Scholar]
  • 9.Szeptycki A. North Korean Collembola. I. The genus Homidia Börner 1906 (Entomobryidae) Acta Zool. Cracov. 1973;31:23–40. [Google Scholar]
  • 10.Szeptycki A. Morpho-Systematic Studies on Collembola. IV. Chaetotaxy of the Entomobryidae and Its Phylogenetical Significance. Polska Akademia Nauk; Kraków, Poland: 1979. pp. 1–219. [Google Scholar]
  • 11.Greenslade P., Stevens M.I., Torricelli G., D’Haese C.A. An ancient Antarctic endemic genus restored: Morphological and molecular support for Gomphiocephalu hodgsoni (Collembola: Hypogastruridae) Syst. Ent. 2011;36:223–240. doi: 10.1111/j.1365-3113.2010.00553.x. [DOI] [Google Scholar]
  • 12.Tamura K., Peterson D., Peterson N., Stecher G., Nei M., Kumar S. MEGA5: Molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol. Biol. Evol. 2011;28:2731–2739. doi: 10.1093/molbev/msr121. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Kimura M. A sample method for estimating evolutionary rates of base substitution through comparative studies of nucleotide-sequences. J. Mol. Evol. 1980;16:111–120. doi: 10.1007/BF01731581. [DOI] [PubMed] [Google Scholar]
  • 14.Lubbock J. Monograph of the Collembola and Thysanura. Ray Society; London, UK: 1873. pp. 1–276. [DOI] [Google Scholar]
  • 15.Börner C. Die Familien der Collembolen. Zool. Anz. 1913;41:315–322. [Google Scholar]
  • 16.Schäffer C. Die Collembolen der Umgebung von Hamburg und benachtbaren Gebeite. Mitt. Nat. His. Musenm. 1896;13:147–216. [Google Scholar]
  • 17.Li L.R., Chen J.X. A New Species of the genus Homidia from Anhui Province, China (Collembola: Entomobryidae) Entomol. Sin. 1997;4:202–205. [Google Scholar]
  • 18.Zhou R., Ma Y.T. New records and two new species of Entomobryinae (Collembola: Entomobryidae) from China. Orient. Insects. 2023;57:756–784. doi: 10.1080/00305316.2022.2123056. [DOI] [Google Scholar]
  • 19.Li L.R., Christiansen K.A. A new species of Homidia from China (Collembola: Entomobryidae) Fla. Entomol. 1997;80:457–460. doi: 10.2307/3495610. [DOI] [Google Scholar]
  • 20.Pan Z.X., Yang W.Q. Reports of two peculiar pigmented new species of genus Homidia (Collembola: Entomobryidae) from Southern China, with description of subadults chaetotaxy. Zootaxa. 2019;4671:369–380. doi: 10.11646/zootaxa.4671.3.3. [DOI] [PubMed] [Google Scholar]
  • 21.Ma Y.T., Pan Z.X. Two new species of Homidia (Collembola: Entomobryidae) from Southwestern China. Zootaxa. 2017;4290:519–530. doi: 10.11646/zootaxa.4290.3.6. [DOI] [Google Scholar]
  • 22.Zhou R., Huang L., Ma Y.T. Smooth post-labial chaetae in Homidia (Collembola, Entomobryidae) and the description of four new species from China with the aid of DNA barcoding. ZooKeys. 2024;1213:41–73. doi: 10.3897/zookeys.1213.123839. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 23.Zhuo P.L., Si C.C., Shi S.D., Pan Z.X. Description of a new species and the first instar larvae of Homidia (Collembola: Entomobryidae) from Taizhou, Zhejiang Province. Entomotaxonomia. 2018;40:148–157. doi: 10.11680/entomotax.2018017. [DOI] [Google Scholar]
  • 24.Zhang F., Yu D.Y., Luo Y.Z., Ho S.Y.W., Wang B.X., Zhu C.D. Cryptic diversity, diversification and vicariance in two species complexes of Tomocerus (Collembola, Tomoceridae) from China. Zool. Scr. 2014;43:393–404. doi: 10.1111/zsc.12056. [DOI] [Google Scholar]
  • 25.Barjadze S., Baquero E., Soto-Adames F.N., Giordano R., Jordana R. New diagnosis for species of Plutomurus Yosii (Collembola, Tomoceridae), with descriptions of two new species from Georgian caves. Zootaxa. 2016;4126:77–96. doi: 10.11646/zootaxa.4126.1.3. [DOI] [PubMed] [Google Scholar]
  • 26.Zhang F., Yu D.Y., Stevens M.I., Ding Y.H. Colouration, chaetotaxy and molecular data provide species-level resolution in a species complex of Dicranocentrus (Collembola: Entomobryidae) Invertebr. Syst. 2018;32:1298–1315. doi: 10.1071/IS18019. [DOI] [Google Scholar]
  • 27.Ye M.L., Huang C.W., Yu D.Y., Sun X., Godeiro N.N., Jiang J.G., Li Z.H., Luan Y.X., Wu D.H., Zhang F. The first checklist of the Collembola of China in the 21th. Zool. Syst. 2025;50:1–94. doi: 10.11865/zs.2025101. [DOI] [Google Scholar]
  • 28.Shi S.D., Pan Z.X., Qi X. A new species of the genus Homidia Börner, 1906 (Collembola: Entomobryidaae) from East China. Zootaxa. 2009;2020:63–68. doi: 10.11646/zootaxa.2020.1.4. [DOI] [Google Scholar]
  • 29.Chen J.X., Lin R. A new Entomobryid species of the genus Homidia (Collembola: Entomobryidae) from Zhejiang, China. Entomotaxonomia. 1998;20:21–24. [Google Scholar]
  • 30.Zhang G.Q., Zhao Y.X., Zhang F. Revisiting the type species of the genus Homidia (Collembola, Entomobryidae) ZooKeys. 2023;1176:1–11. doi: 10.3897/zookeys.1176.109104. [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Articles from Insects are provided here courtesy of Multidisciplinary Digital Publishing Institute (MDPI)

RESOURCES