Homidia pseudokoreana, Lee & Park, 2024

Lee, Inae & Park, Kyung-Hwa, 2024, A new species of Homidia (Collembola: Entomobridae) from Korea, with notes on its DNA data, Zootaxa 5463 (2), pp. 262-272 : 265-270

Homidia pseudokoreana sp. nov.

(Korean name: Nado-boot-toktoki)

Figs 2 –26, Table 3

Type material. Holotype: female on slide, Korea, Jirisan mountain (35°21′41.14′′N, 127°35′09.20′′E), Sannaemyeon, Namwon-si , Jeollabuk-do, 2-V-2017, collected by Kyung-Hwa Park and Inae Lee. Paratypes: 2 females and 2 males, on slides, 5 specimens used for DNA extraction, same data as holotype .

Other material. 3 females and 2 males, 18-VIII-2021, same locality as types .

Material deposition. Holotype is located in the National Institute of Biological Resources , Incheon, Republic of Korea ( NIBR). Other types are housed in the Insect Collection of the Biology Education Department , Jeonbuk National University, Jeonju, Korea ( JBNU) and in the NIBR.

Description. Body length up to 3.5mm. Colour pattern as in Figs 2–3 : Ground color pale yellow and yellowish brown in life, becoming paler in preserved specimens. Eye patches dark blue to dark, with a V-shape patch between them. Antennal segment gradually darker towards tip. Terga of Th. II to Th. III with a median longitudinal irregular dark stripes and lateral dark pigment; the medial stripe on Th. III rather wide, almost rectangle. Abd. II & III darker. Abd. IV with a narrow transverse band posteriorly. Abd V darker laterally. Legs and ventral tube yellow to dark brown. Furcula pale.

Head. Eyes 8+8, G and H smaller and difficult to observe, eye patch with 3 interocular chaetae p, r and t. Antennae

2.8–3.2 times of the cephalic diagonal; antennal segment ratios as I: II: III: IV = 1:1.34–1.5:1.2–1.39:2.17–2.3. Apical bulb of Ant. IV bilobed ( Fig. 9 ). Ant. III organ with 2 rod-like sensory chaetae and 2–3 short guard cheatae ( Fig. 10 ). Ant. II with 4 distal rod-like chaetae ( Fig. 11 ). Dorsal cephalic chaetotaxy with 4 antennal (An1, An2, An3a1, An3), 5 median-ocellar (M1, M2, M3i, M3, M4), and 7(+1) sutural ((S0), S1, S2, S3, S4i, S4, S5i, S5) mac ( Fig. 4 ). Prelabral and labral chaetae as 4/5, 5, 4, all smooth ( Fig. 6 ). Labral papillae absent. Maxillary outer lobe with 1 apical, 1 subapical chaeta and 3 sublobal hairs on sublobal plate ( Figs 5 & 8 ). Chaetal formula of labial base as MRel 1 L 2, chaetae e and l 1 smooth and others ciliate ( Fig. 7 ). Five papillae A–E on labial palp with 0, 5, 0, 4, 4 guard chaetae, respectively; the tip of lateral process (l.p.) almost reaching apex of papilla E.

Thorax. Dorsal thoracic chaetotaxy showed in Fig. 12 . Th. II with 4 centro-medial mac (m1, m2, m2i and m2i2), 3 centro-sublateral mac (m4, m4i and m4p) and about 33 posterior mac. Th. III with about 37–39 mac and 2 sens; p5 and p6 as mac.

Abdomen. Dorsal chaetotaxy of Abd. I–V as in Figs 13 , 18 and 19 . Abd. I with 11 mac (a1, a1i, a2, a3, a5, m2, m2i, m3, m4, m4i and m4p). Abd. II with 6 (a2, a3, m3, m3e, m3ea, m3ep) central and 1 (m5) lateral mac; m2 and a5 bothriotricha. Abd. III with 2 (a2, m3) central and 4 (am6, pm6, p6, m7a) lateral mac; m2, a5 and m5 bothriotricha. Abd. IV with 10–12 mac on anterior part, arranged in irregular transverse row, posterior part with 7 mac (A4, A5, A6, Ae7, B4, B5, B6). Abd. V with 3 sens, middle one postero-external to m3. Complete body sens as 22/122(34)3, ms as 10/10100. Abd. IV length 11 times as Abd. III along dorsal axis.

Legs. Coxal macrochatetal formula as 3 (2 pseudopores)/4+1, 3 (3 pseudopores)/4+2 (pseudopores unclear) ( Figs 22–24 ). Trochanteral organ with 64–77 smooth spiny chaetae ( Fig. 15 ). Tenent hair clavate. Unguis I–III with 3–4, 3–4, 3 inner teeth, respectively; paired basal teeth and unpaired distal tooth; Unguiculus lanceolate, outer edge slightly serrate ( Fig. 14 ).

Ventral tube. Anterior face of ventral tube with many ciliate chaetae; 3+3 of them as macrochaetae, line connecting proximal (Pr) and external-distal (Ed) one oblique to medial furrow ( Fig. 16 ); posterior with 5 smooth and numerous ciliate chaetae; lateral flap with 6 smooth and 13–15 ciliate chaetae ( Fig. 17 ).

Tenaculum. Tenaculum with 4+4 teeth and 1 large, multi-laterally ciliate basal chaeta.

Furcula. Manubrial plaque dorsally with 3 pseudopores and 10–12 ciliate chaetae ( Fig. 21 ), ventrally with 33–36 ciliate chaetae ( Fig. 20 ). Denes with 44–50 spines; basal chaetae (bs1, bs2) multilaterally ciliate, bs1 shorter than bs2. Mucro bidentate with subapical tooth larger than apical one; basal spine short, with tip reaching subapical tooth ( Fig. 25 ).

Ecology. This species was collected from litter and soil mass of a forest dominated by oak tree, Quercus variabilis Blume. Since its existence was reported by Lee et al., 1985, the new species has not been found anywhere in the Korean Peninsula except the Jiri-san Mountain area where collecting sites for this study.

Etymology. The species was named for its the morphological characteristics that show chaetotaxy similar to H. koreana .

Remarks. The new species, Homidia pseudokoreana sp. nov., shows similar color pattern with H. mediofascia Shi, Pan & Bai, 2009 , H. yandargensis Pan, 2015 and H. pseudozhangi Jing & Ma, 2023 from China, in that they have medial longitudinal stripes on thorax II–III. However, it can be easily distinguished from the related two species, H. mediofascia and H. pseudozhangi , by the stripe in new species is wide and confined to the thorax, whereas that of the related two species is narrow and extended to Abd. I and/or II. Also it is can be separated from them by the number of inner teeth on unguis of hind leg (3 in H. pseudokorean sp. nov.; 4 in the related two species), and coxal macrochaetal formula (3/4+1, 3/4+ 2 in H. pseudokoreana sp. nov.; 4/4+2, 3/4+ 2 in the related two species). The longitudinal dark stripe on thorax of this new species rather resembles that of H. yandargensis Pan, 2015 from China, in gradually becoming wider from Th. II to Th. III. However, the relative position of ms/sens on the lateral area of Abd. I (antero-external in H. pseudokoreana sp. nov.; antero-internal in H. yandargensis ), the present of macrochaeta a1 on Abd. V (microchaeta in H. yandargensis ), coxa III without pseudopore (with 2 in H. yandargensis ), the number of inner teeth on unguis III (3 in H. pseudokorean sp. nov.; 4 in H. yandargensis ) and the line connecting proximal (Pr) and external-distal (Ed) macrochatae on anterior face of ventral tube oblique to medial furrow (parallel in H. yandargensis ) make it distinguishable from the related species.

This new species is similar to the Korean species H. koreana Lee & Lee, 1981 in the chaetotaxy of head and posterior Abd. IV, and the number of dental spines. However, it can be morphologically distinguished from H. koreana by the present of medial longitudinal stripe on Th. II–III (absent in H. koreana ), the presence of macrochaetae a1 and a1a on Abd. I (absent in H. koreana ), and the number of spiny chaetae on trochanteral organ (64–77 in H. pseudokoreana sp. nov.; 40–50 in H. koreana ). The genetic data also supported that H. pseudokoreana sp. nov. has apparently different species from H. koreana , even though they showed similar chaetotaxy.

The detailed morphological differences between them are listed in Table 3 .

Figures

FIGURES 2–3. Homidia pseudokoreana sp. nov. 2, dorsal view; 3, lateral view. Scale bars: 500µm.

FIGURES 4–11. Homidia pseudokoreana sp. nov. 4, dorsal chaetotaxy of head; 5, lateral process of labial palp; 6, labrum; 7, labial base; 8, maxillary outer lobe; 9, apex of Ant. IV; 10, Ant. III organ; 11, base of Ant. II. Scale bars: 50µm. ˟ = bothriotricha (Fig 4).

FIGURES 12–17. Homidia pseudokoreana sp. nov. 12, dorsal chaetotaxy of Th. II–III; 13, dorsal chaetotaxy of Abd. I–III; 14, hind foot complex; 15, trochanteral organ; 16, anterioror face of ventral tube; 17, posterior face and lateral flap of ventral tube. Scale bars: 12–13 = 100µm; 14–17 = 50µm. ˟ = bothriotricha and ø = psp (Fig 12–13).

FIGURES 18–25. Homidia pseudokoreana sp. nov. 18, dorsal chaetotaxy of Abd. IV; 19, dorsal chaetotaxy of Abd. V; 20, ventro-apical part of manubrium; 21, manubrial plaque; 22–24, coxal chaetotaxy. 22, fore leg; 23, middle leg; 24, hind leg; 25, mucro; 26, hind foot complex. Scale bars: 18 = 100µm, 19–24 = 50µm, 25–26 = 20µm. ˟ = bothriotricha and ø = psp (Fig 18).