identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
03A8146EFFA5FF742B9CFA11FCF55D68.text	03A8146EFFA5FF742B9CFA11FCF55D68.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Willowsia jacobsoni (Borner 1913)	<div><p>Willowsia jacobsoni (Börner, 1913)</p><p>Figs 1–13 and Tables 2–3</p><p>Sira jacobsoni Börner, 1913: 49, fig. 4, Java, Indonesia (orig. descr.)</p><p>Seira jacobsoni; Salmon, 1964: 503 (comb.)</p><p>Willowsia jacobsoni; Stach, 1965: 362</p><p>Synonyms:</p><p>Sira jacobsoni var. lipostropha Börner, 1913: 51 synonymized Zhang et al. 2011: 8.</p><p>Sira tricincta Schött, 1917: 31 synonymized by Womersley 1937a: 156.</p><p>Sira jacobsoni var. indica Handschin, 1929: 240 synonymized by Mari Mutt 1981: 370 (?).</p><p>Sira parajacobsoni Denis 1929: 105 synonymized by Denis 1941: 44.</p><p>Sira jacobsoni var. handschini Uchida, 1944: 4–5 synonymized by Mutt 1981: 370 (?).</p><p>Sira jacobsoni var. africana Delamare-Deboutteville 1950: 82 synonymized by Mari Mutt 1981: 370 (?).  Willowsia mesothoraxa Nguyen, 2001: 25 synonymized by Zhang et al. 2011: 8.</p><p>Diagnosis. Adult specimens with violet pigment generally over most of the antennae, anterior dorsal margin of the head; females with Th II all pigmented; a dark blue transverse band formed by the posterior margin of Abd II and all Abd III and another dark blue band in Abd IV distally; coxae I–II with weakly pigments; femur III with a distal spot and tibiotarsus I–III with a median strip (Figs 2–3). Scales lance-shaped, with interrupted ribs covering the proximal 1/3 or more (but not completely), present on head and trunk, absent on the appendages (Fig. 6). Ant IV with a unilobed apical bulb (Fig. 4A). Dorsal chaetotaxy with 6 ‘An’, 4 ‘A’, 3 ‘M’, 4 ‘S’, 3 ‘Pa’, 4 ‘Pm’, 7 ‘Pp’ and 4 ‘Pe’ mac (Fig. 9E). Prelabral chaetae ciliate; labral p0–1 chaetae longer than the others (Fig. 5A); labral inner papillae with 4–5 projections and outer papillae with 3–4 projections (Fig. 5B); maxillary palp with 3 inner sublobal appendages; papilla E lateral process finger-shaped and almost reaching the base of the apical appendix; basolateral and basomedian labial fields with M, R, E, L1–2 ciliate, R smaller than the others (Fig. 5A). Th II a, m and p series with 2(a5–5i), 0 and 4(p1–3, p5) mac; Th III a, m and p series with 1(a6), 3(m5–7) and 4(p1–3, p6) mac (Fig. 10E); Abd I–IV macrochaetotaxy formula with 4, 2+1, 2+3, 3–4(5)+12–15 mac (Figs 11E and 12E); tenent hair ciliated and apically capitate; unguis basal teeth on the basal half, median tooth on distal 1/4 and smaller than the basal teeth, apical tooth on distal 1/8 and smaller than others; all unguiculus lamellae (ae, ai, pe, pi) smooth and acuminate, except for unguiculus III pe serrated (Fig. 7A–B); male genital plate papillate, with about 9+9 circumgenital chaetae; mucronal teeth subequal, spine surpassing the apex of the proximal tooth (Fig. 7C).</p><p>Remarks.  Willowsia jacobsoni has been redescribed a few times throughout history, and in general its morphology was depicted similarly by different authors (e.g. Börner 1913; Schött 1917; Handschin 1925; Denis 1929; Mari Mutt 1981; Christiansen &amp; Bellinger 1992; Nguyen 2001; Katz 2017). Even so, there are some differences listed by the previous authors that may be related to variations and/or interpretations, or even observational mistakes.</p><p>The specimens analyzed here, including the juveniles (Figs 2–3), have the same color patterns and sexual dimorphism reported by Mari Mutt (1981) to specimens from Puerto Rico, except the depigmented Th III and the body completely pigmented. On labial posterior row, Mari Mutt reported the occasional presence of two extra chaetae (in basomedian field), and also illustrated (but did not report in his description) two smooth chaetae (L1–2) on basolateral field (Mari Mutt 1981). However, in our analyzed specimens (including a few from Puerto Rico), no extra chaetae were observed, and L1 and L2 were always ciliated, so we do not know whether it could be a very atypical variation or an observational mistake.</p><p>The different interpretations (mac, mes or intermediate chaetae) can be considered in the Th. II dorsal chaetotaxy on to posterior row, with five mac reported by Mari Mutt (1981), four mac observed in our study (Fig. 10E), three mac depicted by Nguyen (2001), or two mac posteriorly seen by Katz (2017). The same happens in Th III, with three (p1–3) (Fig. 10) or one (p3) inner mac, the latter being likely mistakenly described by Nguyen (2001). Katz (2017) considered one inner mac (m4) on Abd I, while other authors (Mari Mutt 1981; Nguyen 2001), including the present work, considered three mac (m2–4) (Fig. 11E). On Abd IV, there may rarely be five inner mac (Mari Mutt 1981), due to the intermediate size (mac or mes) of A3 chaeta (Fig. 12E), but the most common morphology varies between four or three (Sm absent) mac, the latter being a more frequent morphotype (e.g. Nguyen 2001). Still in Abd IV, other variations are revealed here for the first time, as three lateral mac (Fe2a2, Fe2, Fe2p), which were described as always present in Mari Mutt (1981). Concerning variable chaetae, on the head, three mac (p1e2, p2e2–e3) can also be present or absent. In addition, the S6 chaeta was not observed in Katz (2017), but is reported as mic or mac in Mari Mutt (1981). In the present work, S6 chaeta was observed as mac/mes only in the immature’s stages, except in 1 st instar (Fig. 9).</p><p>The differences between the redescriptions herein reported for  W. jacobsoni can influence comparisons (e.g., Katz 2017) and/or identifications, and consequently support descriptions of synonyms (e.g.  W. parajacobsoni,  W. mesothoraxa). This subject has already been discussed before to other  Entomobryidae (e.g. Viana et al. 2022, 2024). Once again, we reinforce caution in the interpretation, and consequently, in the diagnosis of  Willowsia species.</p><p>Examined material. 1 female on slide (INPA): Brazil, Amazonas, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-59.99&amp;materialsCitation.latitude=-3.095" title="Search Plazi for locations around (long -59.99/lat -3.095)">Manaus</a> municipality, on laboratory benchtop in entomology department at the INPA, 03°05’42”S, 59°59’24”W, urban area, 82 m, 16.ii.2020, manual collect, NG Cipola coll. 2 males and 11 females on slides and 14 specimens in alcohol (INPA): idem, except 12-15.iv.2021, JMC Nascimento coll. 9 specimens in alcohol (INPA): <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-60.03583&amp;materialsCitation.latitude=-2.9922223" title="Search Plazi for locations around (long -60.03583/lat -2.9922223)">Tarumã</a> neighborhood, floating in the pool of the "Residencial Nascentes do Tarumã", 02°59’32”S, 60°02’09”W, urban area, 44 m, 05.i.2022, T Mahlmann coll. 1 female on slide (INPA): Pará, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=-48.373608&amp;materialsCitation.latitude=-1.3901111" title="Search Plazi for locations around (long -48.373608/lat -1.3901111)">Ananindeua</a> municipality, urban area of “Águas Lindas” neighborhood, 01°23’24.4”S, 48°22’25.0”W, 31 m, 10-13.viii.2023, pitfall-trap, SS Viana coll. 8 specimens (1 male, 4 females and 3 undetermined) on slides (INHS 148–810): USA, Puerto Rico, Aguada, Coloso Sugar Cane Mill, 18°22'52"N, 67°09'40", on sugar cane litter, 16-17.vi.1999, F. Soto-Adames coll. 1 male and 1 female on slides and 2 specimens in alcohol (20HN-SY7/ NJAU): China, Hainan Province, Sanya Bay, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=109.48394&amp;materialsCitation.latitude=18.278194" title="Search Plazi for locations around (long 109.48394/lat 18.278194)">Sanya</a>, 18°16’41.5”N, 109°29’02.2”E, 2 m., 17.i.2020, D Yu coll. 2 males and 2 females on slides (NUS): Singapore, National University of Singapore (NUS), Kent Ridge campus, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=103.77659&amp;materialsCitation.latitude=1.297111" title="Search Plazi for locations around (long 103.77659/lat 1.297111)">Lower Kent Ridge Rd</a>, forest edge near <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=103.77659&amp;materialsCitation.latitude=1.297111" title="Search Plazi for locations around (long 103.77659/lat 1.297111)">University Hall</a> building, 01°17’49.6”N, 103°46’35.7”E, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=103.77659&amp;materialsCitation.latitude=1.297111" title="Search Plazi for locations around (long 103.77659/lat 1.297111)">Secondary</a> tropical forest, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=103.77659&amp;materialsCitation.latitude=1.297111" title="Search Plazi for locations around (long 103.77659/lat 1.297111)">Adinandra Belukar</a>, 03.vi.2015, Malaise-trap, Maosheng Foo coll. 1 juvenile in 1 st instar, 4 juveniles in 2 nd instar, 2 juveniles in 3 rd instar, 3 juveniles in 4 th instar, 2 males and 11 females on slides and 82 specimens in alcohol (NUS), plus 3 females on slides (INPA): idem, except in Botany Department of the  National University of Singapore, 01.xi.1990, HK Lua coll.</p><p>Geographical records (Fig. 8). INDONESIA: Java, Samarang (= Semarang) (type locality) (Börner 1913: 49); West Java, Tjibodas (actually Cibodas) (Handschin 1925: 237); New Guinea (actually Papua, Indonesia), Cyclops Mountains (Womersley 1937b: 205); Sumatra, Jambi Province (Mawan et al. 2022: 5); Sumatra, Ranau and Wadi Kuala (Handschin 1931: 481). PHILIPPINES: Luzon (Gapud 1971: 14); Laguna, Mount Makiling (Alviola et al. 2021: appendix). AUSTRALIA: North Queensland, Cedar Creek (Schött 1917: 31); Victoria, Cumberland (Womersley 1942: 28). PACIFIC OCEAN ISLANDS: Micronesia, Mariana and Caroline (Uchida 1944: 4–5). JAPAN: Ogasawara, Marcus Island (Uchida 1955: 203). CAMBODIA: Bokkor (= Bokor) (Denis 1948: 240). VIETNAM: Nhatrang (= Nha trang) and DEo-Ca (= Cả Pass) (DEnis 1948: 240); THái BìnH (NGUYEn 2001: 25). NEPAL: Jumbesi and Maedane Karka (Yosii 1966: 509). INDIA: West Bengal (Mandal et al. 2024: 221). SRI LANKA (Handschin 1929: 240). MADAGASCAR: Tamatave (= Toamasina) (Denis 1929: 105). IVORY COAST (Delamare-Deboutteville 1948: 316, 1950: 82, 1952: 73). USA: Maui and Oahu Islands (Folsom 1932: 66; Christiansen &amp; Bellinger 1992: 258). PUERTO RICO: Mayagüez (Mari Mutt 1981: 367); Aguada (Katz 2017: 552). TAIWAN: Taichung (Lee &amp; Park 1989: 275). CHINA: Hainan, Sanya Bay (new record). SINGAPORE: National University of Singapore (new record). BRAZIL: Amazonas, Pará states (new record).</p><p>Postembryonic development of the dorsal chaetotaxy in  W. jacobsoni</p><p>Head dorsal chaetotaxy (Fig. 9). The 1 st instar has 41 primary chaetae in series: 3 ‘An’, 5 ‘A’ (A4 absent), 1 ‘Am’, 5 ‘M’, 3 ‘IO’, 5 ‘S’ (S1, S4, S6 absent), 3 ‘Ps’, 7 ‘Pa’ (Pa4 absent), 2 ‘Pm’ (Pm2 absent), 6 ‘Pp’ and 1 ‘Pe’. In the 2 nd instar, nine secondary chaetae appear, six of which as mac (An1a, An3a, M4i, S6, Pp1e, P2e), besides the modification of mac to mes of many primary chaetae, except the original ‘An’, ‘A’ and ‘IO’ series and other nine mac (M4, S5, S7, Pa1, Pa5, Pm1, Pp1–2, Pe3). Contrarily, Pp5 changes from mes to mac. In the 3 rd instar, only one chaeta appears (Pe5), Pa3 changes to mac, and seven chaetae change as mes (v, t, M4–4i, S6, Pa7, Pp6). In the 4–5 th instars, five more chaetae emerge (Pa7e, Pe6 and two unnamed) and 1 ‘IO’ scale (r), but 5–7 chaetae turn into mac (M1–2, M4, S2–3, Pm3 and Pe4, M1 and S2 as mac or mic) and three others to mic (Ps2, Pa2–2i). Regarding the adults, 16 other chaetae appear (An3a2, An3p, q, s, Ps2i, Pm1e–1e2, Pp1e2, Pp2e–2e3, Pe3i, plus four without clear homologies), 8 of which as mac (Pm1e2, Pp2e2 and Pp2e3 present or absent). Furthermore, three chaetae change to mac (M1, S2 and Pp3), while another eight change to mic (M3, M4i, S6, Ps3, Pa7, Pp4i–5). Both of the extra chaetae (?), as well as Pe6 seen in 4–5th instars, disappear in adults.</p><p>Th II dorsal chaetotaxy (Fig. 10). The 1 st instar a, m and p series have 7 (a1–7), 6 (m1–2, m4–7) and 6 (p1–6) primary chaetae, respectively, plus an atypical extra chaeta anteriorly (aa). In the 2 nd instar, nine secondary chaetae appear (a3i, a4e, m5a, m5e, m6p, m7p–p2, p6e, p6p), all as mac, except a3i as mes. Furthermore, of the primary chaetae, 11 of them remained mac (aa, a2–6, m6, p1–3, p5), while the other primary chaetae changed from mac to mes or remained as mes. In the 3 rd instar, 2 internal scales plus 1 unpaired appear anteriorly, 3 mes from the post-posterior row, plus 8 additional chaetae (a1e, a4p, a4e2, a5i, a6p, a7e, a7p3 and unnamed one), four of which as mac (a1e, a4p, a4e2, a6p), and the rest as mic. Furthermore, two chaetae change from mes to mac (a1, a3i). In the 4–5 th instars, at least 16 chaetae emerge (a3e–3e2, a4a, a4e2a, a4e2p, aap, a5a, a6i–ip, a6p2–p3, m6p2, m7e, p1a, p2e, p 6ei) and 2 scales and 5 mes on the post-posterior row. Additionally, six chaetae of m series (m1–2, m4, m5a–5e) modify from mes to mic. Finally, in adults, several chaetae appear in the anterior collar plus about 15 scales on the post-posterior row, while two mes of p series (p4, p6) change to mic.</p><p>Th III dorsal chaetotaxy (Fig. 10). The 1 st instar a, m and p series have 7 (a1–7), 5 (m1, m4–7) and 6 (p1–6) primary chaetae, respectively. In the 2 nd instar, four secondary chaetae appear (m5i, m5p, m6p, m6e), and most chaetae remain as mes, except six mac (a6, m5–6, p1–3). In the 3 rd instar, a7e chaeta appears, p6 turns into mac and a5p into mes. In the 4–5 th instars, three chaetae emerge (a7a, a7e2, m7e), six more are added to the post-posterior row, and ten change from mes to mic (a1–5, m1, m4, m5p, p4–5). In adults, three chaetae appear on the inner region (a4i–4i2, p2e), at least 18 unnamed chaetae laterally and 17 scales on the post-posterior row.</p><p>Abd I dorsal chaetotaxy (Fig. 11). The 1 st instar a, m and p series have 5 (a1–3, a5–6), 5 (m2–6) and 2 (p5–6) primary chaetae, respectively. In the 2 nd instar, no new chaeta appears, but most chaetae change to mes, except four of m series which remain as mac (m2–4, m6). In the 3 rd instar, one lateral (el) and one chaeta on the post-posterior row appear, and p6 changes to mac. In the 4–5 th instars, one unnamed lateral and five chaetae on the post-posterior row emerge, plus one inner scale. Furthermore, all chaetae of a series transform into mic, except a1. In adults, six chaetae appear (a4i and five unnamed), plus at least 16 scales and two chaetae on the post-posterior row. On m series the m6 chaeta changes from mac to mes.</p><p>Abd II dorsal chaetotaxy (Fig. 11). The 1 st instar a, m and p series have 6 (a1–3, a5–7), 6 (m2–7) and 4 (p4–7) primary chaetae, respectively, plus el chaeta. In the 2 nd instar, three inner chaetae (a1e, m3e–3ea) and three chaetae on the post-posterior row appear. Furthermore, some chaetae change into mic (e.g. a2–3, a6, m4), while others change into mes, except five chaetae (m3, m5–6, p6, el) that remain as mac. In the 3 rd instar, no new chaetae appear and only the p7 mes changes to mac and three chaetae (a1, a7 and p5) change to mic. In the 4–5 th instars, one inner (m3ep) and four unnamed outer chaetae emerge, as well as five chaetae on the post-posterior row. Furthermore, m3e changes to mac and two mac change to mes (p7, el). In adults, one inner and several unnamed outer chaetae appear, including eight and six accessory chaetae on a2 and m2 bothriotricha, respectively, as well as five chaetae and at least 20 scales on the post-posterior row. Among the modifications, a1 become a scale, a7, m6 and p6 become mes, and p4 become a mic.</p><p>Abd III dorsal chaetotaxy (Fig. 11). The 1 st instar a, m and p series have 7 (a1–3, a5–8), 7 (m2–5, am6, pm6, m7) and 4 (p3, p5–7) primary chaetae, respectively, plus el chaeta. In the 2 nd instar, two chaetae (a1a, p6pe) and six unnamed additional chaetae appear on the post-posterior row. Only six primary chaetae remain as mac (a7, m3, am6, pm6, p6–7), while the others change to mes or mic. In the 3 rd instar, two inner (a1e, m3e) and two outer chaetae (unnamed) appear, plus three chaetae on the post-posterior row. Furthermore, two chaetae change to mes (a6, m7), two mes to mic (p3, p5), a1a becomes a scale, and el chaeta apparently disappears (or was not seen). In the 4–5 th instars, three inner (a1p, a2i, a5i) and at least 21 unnamed (plus m7i) outer chaetae emerge, as well as four chaetae on the post-posterior row. Clear modifications include three chaetae (a1, a6, m4) that changed from mes to mic and a1a scale apparently disappears. Additional chaetae appear in adults, including several unnamed outer chaetae, seven accessory chaetae on m2 bothriotrichum, about 12 accessory chaetae around m2 and m5 bothriotricha, and at least 25 scales on the post-posterior row. Among the chaetal changes, one mic become mac (a2) and two mac become mes (a7, p6pe).</p><p>Abd IV dorsal chaetotaxy (Fig. 12). The 1 st instar A–C, T, D–F series have 5 (A1–3, A5–6), 5 (B1–3, B5–6), 4 (C1–4), 7 (T 1–7), 3 (D1–3), 3 (E1–3) and 3 (F1–3) primary chaetae, respectively, plus nine type II sens on inner region. In the 2 nd instar, 12 secondary chaetae (Ae1, Sm, D1p, De3, E1a, D2–2p, E4p, F1a, F2p, Fe2 and one unpaired unnamed chaeta) appear, as well as a posterior sens and four chaetae on the posterior membrane. Additionally, six more mes change to mic (A2–3, B3, C1, D1, E1) and three mes to mac (D3, F1–2). In the 3 rd instar, 14 additional chaetae (Ai1, A5a, Ae5–6, Be1, D3p, De1, Fe2a, Fe2p and five unnamed, one unpaired) and four anterior scales (one unpaired) appear, two mes change to mac (E4p, F2p), and A5 turns into mes. In the 4–5 th instars, 27 chaetae (Ai2, Si, Be3, D2p, F1p, F3p, Fe2a2 and about 20 unnamed emerge, some of which likely as accessory chaetae not yet formed), as well as a median sens and three chaetae on the posterior membrane. In adults, about 10 chaetae (Ai1a and about nine unnamed) appear, as well as two chaetae on the posterior membrane and seven and three accessory chaetae on T 2 and T 4 bothriotricha, respectively. The transformation for mac occurs in five chaetae (F1a, F2p–3, Fe2–2p), but some of them, along with others (A3, Sm, Fe2a2, Fe2p), may show polymorphisms as mac or mes, and at least two chaetae may be present or absent (De1, Fe2).</p><p>Abd V dorsal chaetotaxy (Fig. 12). The 1 st instar a, m and p series have 4 (a1, a3, a5–6), 3 (m2–3, m5) and 5 (p1, p3–6) primary chaetae, respectively (p6 is named as “ ap6 ” by Szeptycki 1979 and Zhang et al. 2019). In the 2 nd instar, seven chaetae (a6a, m3a, m5a, p6ai, p1p, p3pi–3pe) appear and all mes change to mac, except a1 and a3 chaetae. In the 3 rd instar, three more chaetae (a5a, p0, p4a) appear and all secondary chaetae remain as mes or change to mes. In the 4–5 th instars, three chaetae emerge (a5ai, p3a, p6e) and the post-posterior series chaetae change to mic. In adults, 12 chaetae appear (a3a, p5a, p6ae, p5pi–6pi and six unnamed) plus at least six chaetae posteriorly. Furthermore, two chaetae change to mac (a6, p6e) and the posterior-posterior series chaetae revert to mes.</p><p>Mitochondrial genome</p><p>The 10 Gb of sequencing data were sufficient to assemble the mitochondrial genome with adequate read coverage (Fig. 13). The 15,121 bp mitogenome of  W. jacobsoni contains all 37 genes usually seen in arthropods and is similar in length and constitution to other  Collembola genomes. The Pancrustacean ancestral gene order was partially observed, except for an inversion in the location of trnN (Aspartate) and trnR (Arginine). Normally the order is trnR → trnN, bUt in  W. jacobsoni it is trnN → trnR, witH an intErGEnic spacE oF 167 bp in bEtwEEn. THis invErsion was never reported in previous annotations to any other  Collembola mitogenome. Typical ATG/ATA (methionine) start and TAA stop codons were present in most of the protein coding genes (Table 2). Nucleotide content was as follows: A(38 %; 5776 bp); T (36 %; 5228 bp); G(10 %; 1568 bp); C(16 %; 2549 bp). The AT rich control region is 479 bp long and is located between s–rRNA and trnI (Fig. 13).</p></div>	https://treatment.plazi.org/id/03A8146EFFA5FF742B9CFA11FCF55D68	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Cipola, Nikolas Gioia;Katz, Aron D.;Bu, Yun;Godeiro, Nerivania Nunes	Cipola, Nikolas Gioia, Katz, Aron D., Bu, Yun, Godeiro, Nerivania Nunes (2025): Systematics of Willowsia jacobsoni (Börner, 1913) (Collembola, Entomobryidae): morphology, postembryonic development, distribution, mitogenome and phylogeny. Zootaxa 5604 (3): 201-233, DOI: 10.11646/zootaxa.5604.3.1, URL: https://doi.org/10.11646/zootaxa.5604.3.1
03A8146EFFB6FF762B9CFF40FA925E80.text	03A8146EFFB6FF762B9CFF40FA925E80.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Willowsia Shoebotham 1917	<div><p>On  Willowsia distribution</p><p>Willowsia jacobsoni has several records from the Eastern region of the Old World, but it had never been recorded from China mainland (Fig. 8). Due to the main distribution of the genus and the species in the Old World, especially in Asia, we believe that  W. jacobsoni was possibly introduced in the Americas (including Caribbean and Hawaiian Islands), given its ability to occupy different natural and even anthropic habitats (Christiansen &amp; Bellinger 1994: 316). This is the case of Brazilian populations herein reported, which was found in urban areas found in urban areas, representing the first record of the species and the genus in Brazil (Zeppelini et al. 2025). We believe that  W. jacobsoni was probably also introduced into Africa, since no endemic species of  Willowsia has been described for the continent to date (Bellinger et al. 1996 –2024). In the Americas, although there are other species widely distributed (e.g.  W. buski,  W. nigromaculata), the genus has only three species restricted to North America ( W. mexicana,  W. neonigromaculata and  W. pyrrhopygia). The distribution data suggest that Asia is most likely the origin center of  Willowsia, since this region concentrates the greatest richness of the genus, with 37 species (84% of the total).</p></div>	https://treatment.plazi.org/id/03A8146EFFB6FF762B9CFF40FA925E80	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Cipola, Nikolas Gioia;Katz, Aron D.;Bu, Yun;Godeiro, Nerivania Nunes	Cipola, Nikolas Gioia, Katz, Aron D., Bu, Yun, Godeiro, Nerivania Nunes (2025): Systematics of Willowsia jacobsoni (Börner, 1913) (Collembola, Entomobryidae): morphology, postembryonic development, distribution, mitogenome and phylogeny. Zootaxa 5604 (3): 201-233, DOI: 10.11646/zootaxa.5604.3.1, URL: https://doi.org/10.11646/zootaxa.5604.3.1
03A8146EFFB6FF772B9CFD6FFC2E5B58.text	03A8146EFFB6FF772B9CFD6FFC2E5B58.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Willowsia jacobsoni (Börner 1913)	<div><p>On  W. jacobsoni dorsal chaetotaxy development</p><p>In Entomobryoidea, the first nomenclature for the head sutural series was based in  Dicranocentrus Schött ( Orchesellidae), considering eight primary chaetae (S0–7) and based only in adults’ morphology (Mari Mutt 1979). After, there were different proposals (e.g. Jordana &amp; Baquero 2005; Soto-Adames 2008) and descriptions of many Entomobryoidea, including  W. jacobsoni (e.g. Mari Mutt 1981; Katz 2017), labeling differently the more lateral chaetae (S5, S5i or S6) of the sutural series, consequently generating a discrepancy in homology recognition (Cipola et al. 2014, 2018, 2019, 2022; Zhang et al. 2011, 2017; Pan et al. 2011, 2019; Pan &amp; Zhang 2016; Katz 2017; Cipola &amp; Katz 2021; Viana et al. 2022, 2024; Mandal et al. 2024). Another aggravating factor was that some authors considered the closest chaeta to H eye as belonging to the sutural series (e.g. Mari Mutt 1981; Pan et al. 2011; Pan &amp; Zhang 2016; Katz 2017), while this chaeta (s) may better fit the ‘IO’ series, a more consistent observation considering the shared dorsal chaetotaxy pattern of the Entomobryoidea (e.g. Soto-Adames 2008; Cipola et al. 2014, 2018, 2019, 2022; Pan et al. 2011, 2019; Zhang et al. 2011, 2017; Pan &amp; Zhang 2016; Viana et al. 2022, 2024; Mandal et al. 2024). This makes sense considering that among the genera of Entomobryoidea, at least  Homidia jordanai Pan &amp; Zhang, 2011 has all eight primary chaetae (S0–7) already in the 1 st instar (Pan et al. 2011), while some of these chaetae (e.g. S1, S4, S6) may appear secondarily in other taxa, as in  Entomobrya egleri Arlé &amp; Guimarães, 1978,  Homidia breviseta Pan, 2022 in Xiang et al. (2022),  Sinhomidia uniseta Pan, Si &amp; Zhang, 2019 (in Pan et al. 2019) (Xiang et al. 2022; Viana et al. 2024). However, this is not the case of  W. jacobsoni, which consistently lacks S1 and S4 chaetae during all its development (Fig. 9). Regardless, from the head development presented here for the first time in  Willowsia, it was possible to verify that the 1 st instar of  W. jacobsoni is similar to those of other  Entomobryinae genera (Pan et al. 2011, 2019; Xiang et al. 2022; Viana et al. 2024).</p><p>The proposal of eight primary chaetae on the sutural series (S0 to S7) corroborates Mari Mutt (1979), and applies to different Entomobryoidea taxa, reinforcing the consistent morphology and its subsequently homology seen at least in the sutural series of dorsal head chaetae. For this reason, we believe this nomenclature needs to remain standardized in future descriptions.</p><p>In addition to the analysis of the sutural series, the M0 chaeta is lost at least in adulthood (or earlier) in the above mentioned  Entomobryinae taxa (it is absent in  E. egleri), as well as in some  Seirinae, like  Seira (Soto-Adames 2008) and  Lepidocyrtinus Börner, 1903 (personal observation). However, in  W. jacobsoni and in  Lepidocyrtinae overall, this chaeta is likely present in all instars (Barra 1975; Mateos &amp; Winkler 2018; Cipola et al. 2019, 2020; Mateos &amp; Greenslade 2021). The same happens with the Am0 chaeta, which remains stable during the development of  W. jacobsoni, but is lost secondarily in  Sinhomidia uniseta (Pan et al. 2019) and an undescribed species of  Lepidocyrtinus (personal observation). In this sense, our study provides evidence for the first time of the presence of both chaetae (M0, Am0) in  Willowsia, since they are part of the head microchaetotaxy which is usually overlooked to the genus (e.g. Zhang et al. 2011; Pan &amp; Zhang 2016; Katz 2017; Mandal et al. 2024). It is now necessary to verify whether such chaetae are constantly present within  Willowsia lineages and may represent a generic characteristic.</p><p>The 1 st instar chaetotaxy of Th II to Abd V is now known at least to 14  Entomobryinae species distributed across seven genera:  Coecobrya Yosii, 1956 (2),  Entomobrya (3),  Entomobryoides Maynard, 1951 (1),  Homidia Börner, 1906 (3),  Sinella (2),  Sinhomidia Zhang, 2009 in Zhang et al. (2009) (1) and  Willowsia (2) (Szeptycki 1979; Pan et al. 2011, 2019; Zhang et al. 2019a; Xiang et al. 2022; Viana et al. 2024). The 1 st instar  W. jacobsoni has a similar pattern compared to these taxa, but differs especially due to the presence of one extra chaeta (aa) on Th II, which is unclear if it is typical of the genus, as this segment has never been described for this instar before (see Szeptycki 1979; Zhang et al. 2019a). Another difference regards the Abd I, which lacks a typical primary chaeta (m5, a5 was mistakenly named as m5) in  W. buski compared to  W. jacobsoni, but this needs to be better investigated as it could be an observational mistake (see Szeptycki 1979: 166).</p><p>Compared to other  Willowsia taxa, in the 2 nd instar, the Th II of the  W. jacobsoni resembles  W. japonica (in Zhang et al. 2019a) in all primary series, except m4 as mic and p2 as mac (the opposite in  W. japonica), as well as some secondary chaetae are only present in  W. jacobsoni (m5a), while others only occur in  W. japonica (a3a, m2i, m4p, p2e). Furthermore, it is noted that  W. japonica has a secondary chaeta (a4e2) in the same position as the primary chaeta (aa) of  W. jacobsoni, but it is difficult in this case to trace whether they are homologous or not. In Th III,  W. jacobsoni differs only by a5 as mes and m5 as mac (mac and mes, respectively, in  W. japonica), in addition to two secondary chaetae (p2e, m6i) present only in the  W. japonica (see that m5p was named as “ a6i ” in Zhang et al. 2019a). On Abd I,  W. jacobsoni does not hold any secondary chaetae in the 2 nd instar (while m2i is present in  W. japonica), and m6 is a mac (a mic in  W. japonica), but both species have three internal mac as adults, and m6 is lost or was not observed in  W. japonica (see Zhang et al. 2011: 15). The Abd II of  W. jacobsoni differs from  W. japonica by three mac present (m6, p6, el) and one absent (m3e), in addition to some secondary chaetae present (a1e, m3ea) and two unnamed absent (Zhang et al. 2019a). However, the 2 nd instar of both species has three mes on the post-posterior row. It is noted that in  W. jacobsoni, the m3e mac only appears in the 4–5 th instars, while in  W. japonica, it appears in the 2 nd instar, plus the a2 mac emerges only during the 3 rd instar or later (and is absent in  W. jacobsoni). Therefore, the development, as well as the final pattern of Abd II mac is quite different between species. In Abd III,  W. jacobsoni has four more mac (a7, am6, p6pe, p7) compared to  W. japonica, while the latter species has six secondary chaetae (m7a and five unnamed), but both hold mes on the post-posterior row, six in  W. jacobsoni and four in  W. japonica . Furthermore, the a2 chaeta is modified into a mac only in adults of  W. jacobsoni, so this modification probably also occurs in final stages of  W. japonica (Zhang et al. 2011), but this needs to be investigated. The Abd IV of  W. jacobsoni differs from  W. japonica and  W. cassagnaui Zhang, 2015 (in Zhang et al. 2019a) by two chaetae as mac (A5–6) plus more two (D3, E4) absent in  W. cassagnaui . However, in  W. japonica and  W. cassagnaui these internal chaetae, together with the others, result in a total of seven mac in adults (Si, A5–6, C1, Sm, B5–6) (Zhang 2015; Zhang et al. 2011), while in  W. jacobsoni the internal mac is reduced in number, with at least A5 and often A3 and Sm being absent. In different Entomobryoidea, the Si chaeta appears in the 2 nd instar (Zhang et al. 2019a), but in  W. jacobsoni, it atypically appears during the 4 th instar, and remains until adulthood. In this sense, as well as to the other tergal segments, secondary chaetae may appear independently among the three  Willowsia species, including on post-posterior row. The development of the pattern of type II sensilla from the 1 st instar to the adult of  W. jacobsoni is quite stable, differing only in the emergence of an extra posterior sensillum in the 2 nd instar and another anterior sensillum during the 4–5 th instars (Fig. 12). The distribution pattern of these sensilla is also similar compared to  E. egleri instars, only differing in the emergence of one sensillum in the 4 th instar and three sensilla in adults (Viana et al. 2024). On the other hand, this does not seem to be a rule given that there is a reduction in the number of sensilla between the 1 st and 2 nd instars in  H. breviseta (Xiang et al. 2022), for example. Finally, comparing  W. jacobsoni to  W. japonica, there are 10 shared mac on Abd V (a5–6, m2, m5, p1, p3–6), but in  W. japonica three secondary chaetae (p4a, p5a, p6e, named as “ pp6 ” in Zhang et al. 2019a) appear earlier.</p><p>After this study of the dorsal chaetotaxy development of  W. jacobsoni, the species can now be identified and compared in different instars with other congeneric species, a strategy which has already proven successful when applied to diagnose other Entomobryoidea taxa (Soto-Adames 2008; Xiang et al. 2022). Besides, after comparing the development of  W. jacobsoni with other  Entomobryinae taxa, it was possible to verify that a large part of the specific pattern of each species is formed during the 2 nd instar or slightly after (except part of the head in  W. jacobsoni), with few changes in primary macrochaetotaxy until adulthood.</p></div>	https://treatment.plazi.org/id/03A8146EFFB6FF772B9CFD6FFC2E5B58	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Cipola, Nikolas Gioia;Katz, Aron D.;Bu, Yun;Godeiro, Nerivania Nunes	Cipola, Nikolas Gioia, Katz, Aron D., Bu, Yun, Godeiro, Nerivania Nunes (2025): Systematics of Willowsia jacobsoni (Börner, 1913) (Collembola, Entomobryidae): morphology, postembryonic development, distribution, mitogenome and phylogeny. Zootaxa 5604 (3): 201-233, DOI: 10.11646/zootaxa.5604.3.1, URL: https://doi.org/10.11646/zootaxa.5604.3.1
03A8146EFFBAFF7A2B9CFC14FAB95B64.text	03A8146EFFBAFF7A2B9CFC14FAB95B64.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Willowsia jacobsoni (Börner 1913)	<div><p>Systematics of  Willowsia jacobsoni: molecular and developmental insights and the challenges of revealing synapomorphies for the main groups of  Willowsia</p><p>According to Zhang et al. (2011), in a phylogenetic hypothesis based on 54 morphological characters,  W. jacobsoni could be related to  W. mexicana and  Americabrya arida, but this clade was not well supported, in addition to some mistakes in the interpretation of a few characters regarding  W. jacobsoni (e.g. characters 12, 21, 22, 36, 37). Still,  W. mexicana needs to be investigated using molecular markers, since it shares several similarities with  W. jacobsoni, such as Ant IV with unilobed apical bulb; labral papillae with projections; macrochaetotaxy dorsal pattern of the head (except by M1, M4i, Pa2, Pa4, Pp3), including the cervical transverse row of mac; reduction of mac on Th II–III; and Abd II–IV formula with 2+1, 2+3, 4(5)+12(15) mac (Zhang et al. 2007). From a molecular perspective, neither  W. jacobsoni nor  W. mexicana has yet been analyzed using a robust set of markers (eg. UCE, USCO).</p><p>Comparing the 10 species of  Willowsia used in our study, there is no strong morphological evidence that supports the obtained groups, except the absence of p1 mac on Th III which is exclusive to  W. guangdongensis and  W. pseudobuski, and the presence of m5 mac on Th II only seen in  W. fascia,  W. qui,  W. pseudobuski and  W. similis (Table 3). Another possible synapomorphy is a5 mac on Th III shared between the six Chinese species of  Willowsia, but it is also present in  W. buskii . Even though it is not exclusive, and the three  Willowsia species ( W. buski,  W. nigromaculata,  W. neonigromaculata) within the  W. jacobsoni clade lack some mac on Th II (m1, m2, m5) and Th. III (a2, a3, m5i) (Zhang et al. 2011; Cipola &amp; Katz 2021). The shared features in these clusters may not be synapomorphic traits, as certain characteristics can be present in phylogenetically distinct groups (e.g. labral papilla with projection in  W. jacobsoni and  W. pyrrhopygia) (Fig. 14).</p><p>The lack of morphological characteristics able to support the split of polyphyletic  Entomobryinae genera like  Entomobrya and  Willowsia (Zhang et al. 2014, 2015, 2016, 2017, 2019; Katz et al. 2015b; Ding et al. 2019; Cipola &amp; Katz 2021) makes difficult further advances in the subfamily supra-specific systematics. In addition, the low representation of many taxa from these groups in phylogenetic analyzes can generate uncertain groupings, especially for species-rich genera that occur in poorly surveyed biogeographic areas. Thus, this study not only provides valuable data to the understanding of  W. jacobsoni, but also underscores the importance of integrating molecular and morphological approaches in addressing the evolutionary history of entomobryid springtails.</p></div>	https://treatment.plazi.org/id/03A8146EFFBAFF7A2B9CFC14FAB95B64	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Cipola, Nikolas Gioia;Katz, Aron D.;Bu, Yun;Godeiro, Nerivania Nunes	Cipola, Nikolas Gioia, Katz, Aron D., Bu, Yun, Godeiro, Nerivania Nunes (2025): Systematics of Willowsia jacobsoni (Börner, 1913) (Collembola, Entomobryidae): morphology, postembryonic development, distribution, mitogenome and phylogeny. Zootaxa 5604 (3): 201-233, DOI: 10.11646/zootaxa.5604.3.1, URL: https://doi.org/10.11646/zootaxa.5604.3.1
03A8146EFFBAFF7A2B9CFF08FC6B5F10.text	03A8146EFFBAFF7A2B9CFF08FC6B5F10.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Willowsia Shoebotham 1917	<div><p>On  Willowsia polyphyly</p><p>Willowsia was previously recovered as a monophyletic taxon based on morphological data (Zhang et al. 2011), although this was hypothesized through an analysis using a single (and likely inappropriate) outgroup,  Americabrya arida (Christiansen &amp; Bellinger, 1980) . However our results, based on molecular data, corroborate previous studies on  Willowsia polyphyly, as well as the nonexistence of  Willowsiinae (Zhang et al. 2014, 2015, 2016, 2017; Katz et al. 2015b; Zhang &amp; Deharveng 2015; Ding et al. 2019; Cipola &amp; Katz 2021).</p><p>Regarding our tree, the large clade gathering the 12  Willowsia sampled taxa mixed with other  Entomobryinae genera was recovered as the sister group of Neotropical scaled  Entomobryinae ( Lepidocyrtoides Schött, 1917 and  Lepidosira), although with low support (pp = 0.37; bs = 60). This grouping may be reasonable, considering that most Entomobryoidea taxa have type I scales (Mari Mutt 1979; Zhang et al. 2014, 2016; Cipola et al. 2014, 2017, 2018, 2022; Nunes et al. 2019), probably a plesiomorphic condition of  Entomobryidae, kept like this only in  W. japonica within the clade. Regardless, the branch gathering seven Asian  Willowsia taxa (pp = 0.77; bs = 73) likely belongs to another genus, and this is probably due to the independent emergence of scales, as already observed to other  Entomobryinae taxa (Zhang et al. 2014). Our results indicated that the type of body scales has no phylogenetic significance for sustaining or helping to split  Willowsia, since different types of scales appear mixed in our phylogeny (Fig. 14). In this sense, new analyses using the same species but new samples need to be done to confirm if  E. multifasciata,  Sinella curviseta and  S. longisensilla were correctly identified, since they were the only unscaled  Entomobryinae within the clade with the  Willowsia species.</p></div>	https://treatment.plazi.org/id/03A8146EFFBAFF7A2B9CFF08FC6B5F10	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		MagnoliaPress via Plazi	Cipola, Nikolas Gioia;Katz, Aron D.;Bu, Yun;Godeiro, Nerivania Nunes	Cipola, Nikolas Gioia, Katz, Aron D., Bu, Yun, Godeiro, Nerivania Nunes (2025): Systematics of Willowsia jacobsoni (Börner, 1913) (Collembola, Entomobryidae): morphology, postembryonic development, distribution, mitogenome and phylogeny. Zootaxa 5604 (3): 201-233, DOI: 10.11646/zootaxa.5604.3.1, URL: https://doi.org/10.11646/zootaxa.5604.3.1
