Alloscopus ramanai Nilsai, Jantarit & Jaitrong sp. nov.

Materials

Type status: Holotype. Occurrence: recordNumber: # THA_AN_PKN01_1-001; recordedBy: Nilsai, A, Jantarit, S & Jaitrong, W; individualCount: 1; sex: Female; lifeStage: adult; occurrenceID: 715D8AE6-3B8E-5488-8EBB-49E70D7B6B75; Taxon: scientificName: Collembola; phylum: Arthropoda; class: Collembola; family: Orchesellidae; genus: Alloscopus; Location: continent: Asia; country: Thailand; countryCode: TH; county: Pathum Thani; locality: Khlong Luang; verbatimLocality: A forest plantation located in a protected zone of the National History Museum Thailand (THNSM) at the Ramanai 9 building in Pathum Thani Province; verbatimElevation: 4-5; minimumElevationInMeters: 3; maximumElevationInMeters: 6; verbatimCoordinates: 14°3'39.657"N, 100°43'1.782"E; verbatimCoordinateSystem: degrees minutes seconds; verbatimSRS: WGS 84; coordinateUncertaintyInMeters: 30; Identification: identifiedBy: Nilsai, A, Jantarit, J & Jaitrong, W; Event: samplingProtocol: Aspirator (Nilsai, A & Jeenthong, T); year: 2025; month: iv; day: 13; habitat: the leaf litter and soil; Record Level: language: en; Material Entity: disposition: In the collection of the Animal and Plant Herbarium, Faculty of Science and Digital Innovation, Thaksin University, Thailand (APH-TSU)

Type status: Paratype. Occurrence: recordNumber: THNHM-I-0003518 to THNHM-I-00030521; recordedBy: Nilsai, A, Jantarit, S & Jaitrong, W; individualCount: 4; sex: 2 females; lifeStage: 2 adults, 2 subadults; occurrenceID: E6293B1F-E434-58BB-A04B-26BBACB8AA54; Taxon: phylum: Arthropoda; class: Collembola; family: Orchesellidae; genus: Alloscopus; Location: continent: Asia; country: Thailand; countryCode: TH; county: Pathum Thani; locality: Khlong Luang; verbatimLocality: A forest plantation located in a protected zone of the National History Museum Thailand (THNSM) at the Ramanai 9 building in Pathum Thani Province; verbatimElevation: 4-5; minimumElevationInMeters: 3; maximumElevationInMeters: 6; verbatimCoordinates: 14°3'39.657"N, 100°43'1.782"E; verbatimCoordinateSystem: degrees minutes seconds; verbatimSRS: WGS 84; coordinateUncertaintyInMeters: 30; Identification: identifiedBy: Nilsai, A, Jantarit, J & Jaitrong, W; Event: samplingProtocol: Aspirator (Nilsai, A & Jeenthong, T); year: 2025; month: iv; day: 13; habitat: the leaf litter and soil; Record Level: language: en; Material Entity: disposition: In the collection of Natural History Museum, Thailand (THNHM)

Type status: Paratype. Occurrence: recordNumber: # THA_AN_PKN01-1 - 002 and # THA_AN_PKN01-1-003; recordedBy: Nilsai, A, Jantarit, S & Jaitrong, W; individualCount: 2; sex: 1 female, 1 subadult; lifeStage: 1 adults, 1 subadults; occurrenceID: ECB9DAEE-BEB9-5D9C-BEA0-E86D98564CFD; Taxon: phylum: Arthropoda; class: Collembola; family: Orchesellidae; genus: Alloscopus; Location: continent: Asia; country: Thailand; countryCode: TH; county: Pathum Thani; locality: Khlong Luang; verbatimLocality: A forest plantation located in a protected zone of the National History Museum Thailand (THNSM) at the Ramanai 9 building in Pathum Thani Province; verbatimElevation: 4-5; minimumElevationInMeters: 3; maximumElevationInMeters: 6; verbatimCoordinates: 14°3'39.657"N, 100°43'1.782"E; verbatimCoordinateSystem: degrees minutes seconds; verbatimSRS: WGS 84; coordinateUncertaintyInMeters: 30; Identification: identifiedBy: Nilsai, A, Jantarit, J & Jaitrong, W; Event: samplingProtocol: Aspirator (Nilsai, A & Jeenthong, T); year: 2025; month: iv; day: 13; habitat: the leaf litter and soil; Record Level: language: en; Material Entity: disposition: In the collection of the Animal and Plant Herbarium, Faculty of Science and Digital Innovation, Thaksin University, Thailand (APH-TSU)

Type status: Paratype. Occurrence: recordedBy: Nilsai, A, Jantarit, S & Jaitrong, W; individualCount: 2; lifeStage: 2 subadults; occurrenceID: 132709A5-3D36-59FD-99E2-057B20A769F9; Taxon: phylum: Arthropoda; class: Collembola; family: Orchesellidae; genus: Alloscopus; Location: continent: Asia; country: Thailand; countryCode: TH; county: Pathum Thani; locality: Khlong Luang; verbatimLocality: A forest plantation located in a protected zone of the National History Museum Thailand (THNSM) at the Ramanai 9 building in Pathum Thani Province; verbatimElevation: 4-5; minimumElevationInMeters: 3; maximumElevationInMeters: 6; verbatimCoordinates: 14°3'39.657"N, 100°43'1.782"E; verbatimCoordinateSystem: degrees minutes seconds; verbatimSRS: WGS 84; coordinateUncertaintyInMeters: 30; Identification: identifiedBy: Nilsai, A, Jantarit, J & Jaitrong, W; Event: samplingProtocol: Aspirator (Nilsai, A & Jeenthong, T); year: 2025; month: iv; day: 13; habitat: the leaf litter and soil; Record Level: language: en; Material Entity: disposition: In the collection of the Princess Maha Chakri Sirindhorn Natural History Museum (NHM-PSU)

Description

Medium-size Orchesellidae, with body length (head + trunk) ranging from 1.1–1.4 mm. Scales present on both sides of Ant. I – II, on both sides of the head, on the entire body, on legs (coxa to femur) and on the ventral tube and furca. Body colour whitish with orange dots (Fig. 1 A). Ocular patch present with small dark spot (Fig. 1 A). Antennae shorter than body (Fig. 1 A, Fig. 2 A and Fig. 6). Eyes absent. Body slender, not bent nor humped at level of Th. II. Pseudopores present as round, flat discs, as large as mac sockets, present on various parts of body: antennae, head, tergites, coxae and manubrium. On antennae, psp located on tip of Ant. II and III (2 on each segment) (Fig. 2 C). On head, 1 + 1 psp located laterally anterior to PAO (Fig. 3 F). On tergites, 1 + 1 psp close to axis from Th. II to Abd. IV (Fig. 4 A). On coxae, 1 + 1 psp on coxa I and II, located close to longitudinal rows of chaetae (Fig. 4 D). On manubrium, 2 + 2 dorso-apical ones (Fig. 5 C).

Antennae: Antennae elongated, with total length measuring 1.51–2.31 times cephalic diagonal and 0.34–0.48 times as long as body (head + trunk) (n = 4). Ant. I subdivided (Ia and Ib), Ant. III – IV annulated, except for their proximal and distal part (Fig. 1 A, Fig. 2 A and Fig. 6). Ant. II – III sometimes fused, not annulated. Ant. I (a + b): II: III: IV = 1: 0.95–1.10: 1.26–1.36: 1.51–1.62 (Fig. 1 A, Fig. 2 A, Fig. 3 H and Fig. 6). Antennal chaetae multiple, with ordinary chaetae, S-chaetae and scales (as described in Jantarit and Sangsiri (2020) and Jantarit et al. 2025. Scales oval to rounded and of medium size (11–13 x 16–24 μm). Smooth spiny mic present at base of antennae, with 4 dorsal and 3 ventral on Ant. Ia (Fig. 3 H), 2 internal, 2 external and 1 ventral on Ant. II. Ant. II organ with 2 – 3 swollen S-chaetae distally (Fig. 2 F). Chaetal type morphology of antennae not analysed in this work. Ant. III organ with typical 5 chaetae with two internal paddle-like chaetae in the middle (Fig. 2 E). Subapical organite not distinctly knobbed, apical not enlarged, inserted dorsally near the tip of Ant. IV, with apical guard chaetae (Fig. 3 C).

Mouthparts: Prelabral and labral chaetae 4 / 5, 5, 4, all smooth, acuminate, subequal, except chaetae of proximal row slightly longer than others. Four labral papillae, conical, minute (Fig. 2 G and Fig. 3 B). Ventral complex of labrum with two slightly asymmetrical multi-toothed combs and a pair of thin, sinuous, unequal tubules below. Maxillary outer lobe with 1 basal chaeta, simple maxillary palp, 4 sublobal appendages, all smooth (Fig. 2 G and Fig. 3 D). Labial palp with 5 smooth, acuminate proximal chaetae and 5 papillae (A = 0, B = 5, C = 0, D = 4, E = 4) (Fig. 2 G and Fig. 3 E). Labial papilla E with lateral process subcylindrical apically, not reaching apex of papilla (Fig. 3 E). Mandible asymmetrical (right with 4 and left with 5 teeth) on all examined specimens.

Ventral head chaetotaxy: Chaetae of labial basis as M 1 m 2 rel 1 l 2, chaetae M 1 ciliated, m 2, e and l 2 smooth, subequal and longest, r and l 1 smooth, subequal and shortest (Fig. 2 G and Fig. 3 A). Postlabial quadrangle (PLQ) with 4 + 4 weakly-serrated chaetae (Fig. 3 A). Dense cover of scales and weakly-serrated chaetae.

Dorsal head chaetotaxy: Dorsal cephalic chaetotaxy with stable chaetae arrangement as in Fig. 3 F. Head ‘ An’ series with 8 + 8 chaetae, mac, ‘ A’ series with 5 + 5, mac (A 0, A 2 – A 5), A 1 as mic; ‘ M’ series with 3 + 3 mac (M 1 – M 3), sutural area with 7 + 7 mac (S 0, S 1, S 3–6, S 6 i) and 2 unnamed mic between series ‘ M’ and ‘ S’; interocular series with 3 + 3 chaetae (p as mac, t and r as mic); postsutural area with 3 + 3 mic (Ps 2–3 and 5); post-occipital anterior area with 1 + 1 mac (Pa 5), 1 + 1 short cephalic tric (Pa 6) and 1 + 1 unnamed mic laterally; post-occipital posterior area with 3 + 3 mic (Pp 3 and Pp 5–6); head laterally with several unnamed mac. Eyes absent. PAO shape irregular (three overlapping ovals) located just below antennal mac (Fig. 3 F).

Dorsal chaetotaxy: Formulas for Th. II – Abd. V: psp formula as 1, 1 / 1, 1, 1, 1, 0; tric formula as 0, 0 / 0, 2, 3, 2, 0; ms formula as 1, 0 / 1, 0, 1, 0, 0; sens formula as 2, 2 / 1, 3, 3, 3, 3; mac formula as 10, 8 / 3, 1, 3, 4, 3. Mac arrangement stable; multiplets anteriorly on Th. II. Th. II with 5 + 5 anterior central mac (a 5, m 2, m 4, m 4 i, m 4 p) and 5 + 5 posterior mac (p 1–3, p 5, p 2 e). Th. III with 6 + 6 central mac (a 2, a 4–5, p 1–3) and 2 + 2 lateral mac (a 6, m 7). Abd. I with 3 + 3 central mac (m 2–4). Abd. II with 1 + 1 central mac (m 3). Abd. III with 1 + 1 central mac (m 3) and 2 + 2 lateral mac (p 6, pm 6). Abd. IV with 2 + 2 central mac (A 3, A 6); 2 + 2 lateral mac (E 3, F 1); and at least 12 + 12 S-like chaetae. Abd. V with 2 + 2 central mac (m 2–3) and 1 + 1 lateral mac (m 5) (Fig. 4 A).

Legs: with ordinary ciliated (mes to mac), smooth chaetae and scales; mic not seen. Scales cover the coxa, trochanter and femur. Tita of leg III is slightly longer than tita of legs I and II. Subcoxa of leg I with 4 + 4 mac, subcoxa of leg II with 4–5 + 4 – 5 mac and 4 + 4 mes, subcoxa of leg III with 3–4 + 3 – 4 mes anteriorly and 3–4 + 3 – 4 mac posteriorly. Coxa of leg I with 2 proximal psp, 4–5 anterior mes and 4 posterior mac; coxa of leg II with 5 mac in anterior row, 4–5 mac in posterior row and 1 proximal psp in between, at least row of 2–3 mes posteriorly; coxa of leg III with at least 7 chaetae: 1 mac, 2 mes anteriorly, (5 mac, 1–2 mes posteriorly) and 1 proximal psp (Fig. 4 D). Trochanteral organ with 17–18 smooth, straight, unequal spine-like chaetae (n = 3) (Fig. 3 J). Distal whorl of tita with 9–10 subequal ciliated chaetae, irregularly arranged and a thin, acuminate, clavate tenent hair. Tita with a long, smooth chaeta latero-distally. Presence of one smooth chaeta on tita of leg III latero-distally (one specimen with two smooth chaetae). Ventro-distal smooth chaeta of tita III thin, erected, pointed, longer than tenent hair or unguiculus (Fig. 5 B). Pretarsal minute on the anterior and posterior sides. Unguis with one strong outer tooth and one lateral tooth on each side, inner edge with paired basal teeth and two unpaired teeth. Unguiculus ~ 0.5 x as long as the inner edge of unguis, slightly swollen baso-internally, pointed apically with a large outer tooth (Fig. 5 A – B).

Ventral tube: Ventral tube about 2 times longer than wide, with scales on the posterior side. Anteriorly with 5 + 5 subequal ciliated chaetae (Fig. 2 D and Fig. 4 B). The posterior ventral tube not clearly seen in all specimens. Lateral flaps with 11 + 11 smooth chaetae (Fig. 4 C).

Furcal complex: Tenaculum with 1 smooth chaeta and 4 large teeth of decreasing size from the basal to distal one on each ramus (Fig. 3 I). Ratio of manubrium: dens: mucro = 5.11: 9: 1 (n = 5). Mucrodens is about 2.0 times longer than the manubrium (n = 5). Manubrium dorsally densely covered with ciliated mes with a row of 5–6 + 5 – 6 smooth chaetae on each side (Fig. 5 D). Manubrial plate with 2 + 2 psp and 3 ciliated chaetae (Fig. 5 C). Manubrium ventrally with densely medium-sized scales. Dens curved, tapering, constituted of a rather short basal part hardly crenulated, long medial part with well-defined dorsal crenulations and short, thinner, smooth distal part, smooth section about 4 times as long as the mucro. Dens basally with 1 + 1 row of 4–5 finely ciliated spines on the inner side (normally with 5 + 5 with sometimes asymmetry) (Fig. 5 C). Mucro bidentate, without basal spine (Fig. 5 E).

Genital plate: Female with 2 + 2 smooth mic, 1 pair on anterior and posterior lobes (Fig. 3 G). Male was not found in this study.

Diagnosis

Alloscopus ramanai sp. nov. exhibits the morphological similarity to A. tetracanthus Börner 1906, a species reported from Australia, Indonesia, Malaysia, Singapore, Papua New Guinea, India, New Britain, Micronesia and Thailand (Chiang Mai Province). Both species share several morphological characters, including a dark red eye patch with reddish to dark dot pigmentation, a semi-divided PAO, labial basis M 1 (m) m 2 rel 1 l 2, four spiniform labral papillae, 4–5 central and 4–5 posterior mac on Th. II, six central mac on Th. III, two central mac on Abd. IV, 0–2 inner unpaired ungual teeth, the presence of teeth on the unguiculus, smooth chaetae on the tibiotarsi, a similar number of chaetae on the manubrium and 4–7 spines on the dens. However, Alloscopus ramanai sp. nov. can be distinguished from A. tetracanthus by the absence of eyes (vs. 1 + 1), orange dot pigmentation (vs. lack of pigmentation) and the presence of five macrochaetae on the “ A ” series of the dorsal head chaetotaxy (vs. four). Furthermore, A. ramanai sp. nov. can be separated from all other Thai Alloscopus species by the following unique combination of characters: (1) two lateral mac on Abd. III (vs. one in other species); (2) two lateral mac on Abd. IV (vs. four in other species); and (3) five chaetae on the anterior face of the ventral tube (vs. 8 + 8 in A. tetracanthus, 7–9 + 7 – 9 in A. whitteni, 9 + 9 in A. namtip, 6 + 6 in A. jantapasoae and 7 + 7 in A. sago). Diagnostic characters of this new species and all known six species in Thailand are provided in Table 1.

Etymology

The new species was collected in the vicinity of the Rama 9 Museum, part of the National Science Museum, Thailand, which serves as the locality. The specific epithet ramanai is derived from the name of the Museum and is used as a noun in apposition, honouring the institution.

Distribution

Pathum Thani, Thailand (central part).

Ecology

The new species was found and collected from the leaf litter and soil near a lotus pond (Bueng Bua) at a forest plantation, located in a protected zone managed by the staff of the National History Museum Thailand (NSM) at the Rama 9 (Ramanai) building in Pathum Thani Province. The plantation is designated for the education and conservation of tropical plant species. The area supports a heterogeneous assemblage of vegetation, including wetland and mangrove-associated taxa (e. g. Rhizophora spp., Sonneratia sp.) as well as terrestrial tropical plant families such as Anacardiaceae and Fabaceae (Fig. 1 B – C). According to Good’s biogeographic classification (Good 1974), central Thailand lies within the Indo-Malayan (Oriental) Region of the Palaeotropical Kingdom. The local climate is classified as tropical savannah with a dry winter (Aw) under the Köppen-Geiger climate classification system (Kottek et al. 2006).