Three new genera and four new species are described from Java, Indonesia: Javagone gen. nov., with Javagone maribaya sp. nov. as the type species; Javanaria gen. nov., with Javanaria gracilipes sp. nov. as the type species; Javanyphia gen. nov., with Javanyphia gede sp. nov. as the type species, and Parameioneta javaensis sp. nov. A new synonym and a new combination are proposed: Walckenaeria caobangensisTu & Li, 2004 syn. nov. is a junior synonym of Nasoona asocialis (Wunderlich, 1974), Parameioneta sulawesi (Tanasevitch, in Tanasevitch & Stenchly, 2012) comb. nov. is transferred from MaorinetaMillidge, 1988. The linyphiid fauna of Java (including the new species described here) contains 20 species, is characterized as Oriental, demonstrates weak relations to the East Asian Palaearctic fauna and does not show any relations to the rich linyphiid fauna of the neighboring Australian Region. An annotated list of the Javanese linyphiids is given and the zoogeographical composition of the fauna is briefly discussed.
INTRODUCTION
The linyphiid spider fauna of the Indonesian island of Java was previously known to contain 15 species, seven of which are known only from there (Simon, 1894, 1905; Helsdingen, 1979, 1985a; Millidge & Russell-Smith, 1992; Tanasevitch, 2017a, b, 2019a, b). Four additional new species from Java, three of them each belonging to a new genus, were found in the spider collection of the Muséum d'histoire naturelle de Genève, Switzerland (MHNG). The present paper provides descriptions of new taxa, some nomenclature changes, and a short zoogeographical analysis of the Javanese linyphiid spider fauna.
MATERIAL AND METHODS
This paper is based on material kept at the MHNG. Sample numbers are given in square brackets. Specimens preserved in 70% ethanol were studied using a MBS-9 stereomicroscope. A Levenhuk C-800 digital camera was used for photos. The terminology of copulatory organs mainly follows that of Helsdingen (1965), Hormiga (2000) and Tanasevitch (1998). Leg chaetotaxy is presented in a formula, e.g., 2.2.1.1, which refers to the number of dorsal spines on tibiae I-IV. The sequence of leg segment measurements is as follows: femur + patella + tibia + metatarsus + tarsus. All measurements are given in mm. Scale lines in the figures correspond to 0.1 mm unless indicated otherwise. Figure numbers are given above the scale lines, the alternative distance below them.
Abbreviations
a.s.l.
above sea-level
C
convector sensu Tanasevitch (1998)
D
duct
DSA
distal suprategular apophysis sensu Hormiga (2000)
E
embolus
EP
embolus proper sensu Saaristo (1971)
LC
lamella characteristica
MB
main body of embolus
MM
median membrane sensu Helsdingen (1965)
Mt
metatarsus
Pr
protegulum sensu Holm (1979)
R
radix
TA
terminal apophysis sensu Helsdingen (1965)
TO
tegular outgrowth
TmI
position of trichobothrium on metatarsus I
TAXONOMY
Order Araneae Clerck, 1757
Family Linyphiidae Blackwall, 1859
Subfamily Erigoninae Emerton, 1882
Javagone gen. nov.
Type species: Javagone maribaya sp. nov.
Etymology: The generic name is a combination of two words: “Java”, the “terra typica”, and part of the generic name Erigone. The gender is feminine.
Diagnosis: The genus contains medium-sized erigonines, with a total length of about 1.7, which are characterized by the following combination of somatic and genitalic characters:
1) Carapace unmodified, eyes somewhat enlarged, cephalic pits (= sulci) absent (Figs 1-4).
2) Legs relatively long and slender.
3) Leg chaetotaxy formula 1.1.1.1; metatarsi I-IV each with a trichobothrium; TmI about 0.31.
4) Palpal tibia simple, slightly modified (Figs 10, 13).
5) Paracymbium relatively large, L-shaped (Fig. 12).
6) Median membrane reduced.
7) Distal suprategular apophysis moderately developed (see Fig. 10).
8) Embolus relatively thin, semi-looped; radix small; convector present, massive (Figs 10-11, 14).
Species included: Only the type species, Javagone maribaya sp. nov.
Taxonomic remarks: Among more than 400 known genera of the subfamily Erigoninae only 23 show the leg chaetotaxy formula 1.1.1.1 coupled with the presence of a trichobothrium on MtIV. No other genera with the same chaeto- and trichobothriotaxy have been recorded from the Oriental Region, except for the monotypic genus Cirrosus Zhao & Li, 2014, known from Xishuangbanna, Yunnan Province, China (Zhao & Li, 2014), an area situated on the border between the Palaearctic and Oriental realms. Judging from the male palp conformation, Javagone maribaya sp. nov. does not fit into Cirrosus or any other known linyphiid genus. The peculiar structure of the male palp and the absence of the corresponding female make it difficult at the moment to evaluate the possible relationships of the new genus. It is most likely with still unknown Oriental erigonines.
Distribution: Known only from the type locality on Java, Indonesia.
Javagone maribaya sp. nov.
Figs 1-4, 10-14
Holotype: MHNG; male [sample 20a]; INDONESIA, Java, West Java Province, 22 km NE of Bandung, Maribaya, hand collecting; 27.VII.1984; leg. J. Robert.
Etymology: The specific epithet is a name in apposition referring to the type locality, the Maribaya Nature Area, Java, Indonesia.
Description: Male holotype. Total length 1.64. Carapace unmodified, as in Figs 1-4, 0.75 long, 0.63 wide, pale brown. Eyes slightly enlarged, as in Figs 3-4. Chelicerae 0.30 long, mastidion absent. Legs yellow to pale yellow. Leg I 3.16 long (0.90 + 0.23 + 0.78 + 0.75 + 0.50), leg IV 3.20 (0.90 + 0.20 + 0.85 + 0.80 + 0.45). Chaetotaxy 1.1.1.1. Length of spines 1-2 diameters of corresponding leg segment. Each metatarsus with a trichobothrium. TmI 0.31. Palp (Figs 10-14): Tibia short, slightly widening distally. Paracymbium relatively large, L-shaped, hooked apically. Distal suprategular apophysis short, linguiform, rounded distally. Median membrane reduced. Convector massive, complex, boat-shaped, its largest lobe directed distad and covering embolus. Embolus relatively thin, semi-looped, with a membranous edge on inner side. Radix very small, triangular. Abdomen 1.05 long, 0.63 wide, pale grey, almost white, with slightly darkened end, as shown in Fig. 1.
Female. Unknown.
Taxonomic remarks: See above under genus description.
Distribution: Known only from the type locality on Java, Indonesia.
Range: Javanese.
Javanaria gen. nov.
Type species: Javanaria gracilipes sp. nov.
Etymology: The generic name is a combination of two words: “Java”, the “terra typica”, and a part of the generic name Nasoonaria. Males of Nasoonaria, like males of the type species of the new genus, have an extremely developed distal suprategular apophysis. The gender of the new name is feminine.
Diagnosis: The genus contains large-sized erigonines with relatively long and slender legs, with a total length of 2.2-2.3, which are characterized by the following combination of somatic and genitalic characters:
1) Carapace slightly modified, eyes somewhat enlarged, cephalic pits (= sulci) absent (Figs 5-6).
2) Abdomen with a dorsal pattern (Fig. 5).
3) Legs relatively long and slender.
4) Chaetotaxy formula 2.2.1.1; each metatarsus with a trichobothrium; TmI 0.52-0.60.
5) Palpal tibia unmodified.
6) Paracymbium long and narrow (Fig. 15).
7) Median membrane strongly reduced.
8) Distal suprategular apophysis extremely developed, massive (Figs 15, 18).
9) Radix strongly reduced, embolus relatively wide, flat, convector absent (Figs 19-20).
Species included: Only the type species, Javanaria gracilipes sp. nov.
Taxonomic remarks: In its large size and long legs J. gracilipes sp. nov. resembles some taxa of the subfamilies Linyphiinae and Micronetinae, but its palpal conformation is of the classically erigonine-type. The palp of J. gracilipes sp. nov. somewhat resembles that of Nasoonaria. However, this similarity is superficial, mainly due to the large distal suprategular apophysis. Today its is impossible to find a genus among the known erigonines to which Javanaria gen. nov. appears to be close. Most likely the closest relatives will be found among taxa not yet described.
Distribution: Known only from the type locality on Java, Indonesia.
Figs 1-9.
Photographs of males: the holotype of Javagone maribaya sp. nov. (1-4), the paratype of Javanaria gracilipes sp. nov. (5-6) and the holotype (7) and both paratypes (8-9) of Javanyphia gede sp. nov. (1, 5, 8-9) Habitus, dorsal view. (2, 6-7) Prosoma, lateral view. (3) Prosoma, frontal view. (4). Prosoma, dorsal view.
Figs 10-14.
Details of male palp structure of Javagone maribaya sp. nov., holotype. (10-11) Right palp, retrolateral and prolateral views, respectively. (12) Palpal tibia and paracymbium, lateral view. (13) Palpal tibia, dorsal view. (14) Embolic division, retrolateral view.
Javanaria gracilipes sp. nov.
Figs 5-6, 15-20
Holotype: MHNG; male [sample Sar-87/28]; INDONESIA, Java, West Java Province, Cibodas, environs of Botanical Garden, 1250-1300 m a.s.l., beating from vegetation in the low part of the garden; 27.XI.1987; leg. C. Lienhard.
Paratype: MHNG; male; collected together with the holotype.
Etymology: The specific epithet is a Latin noun referring to the relatively long and slender legs of the holotype.
Description: Male paratype. Total length 2.20. Carapace slightly modified: its ocular part protruding forward, as shown in Fig. 6; 0.95 long, 0.65 wide, reddish pale brown. Eyes somewhat enlarged. Chelicerae 0.38 long, mastidion absent. Legs pale yellow to yellow. Leg I 4.51 long (1.25 + 0.25 + 1.15 + 1.13 + 0.73), leg IV 3.89 (1.13 + 0.25 + 0.93 + 0.98 + 0.60). Chaetotaxy 2.2.1.1. Length of spines 1-2.5 diameters of corresponding leg segment. Each metatarsus with a trichobothrium. TmI 0.59. Palp (Figs 15-20): Tibia widened distally, unmodified. Paracymbium slender, its middle part long, its distal part short and bent. Distal suprategular apophysis massive, wide, with three long and pointed processes, the distal one longest. Median membrane strongly reduced, developed as a short, narrow and curved apophysis. Embolus flat, wide at base, gradually narrowing towards needle-shaped apex. Radix strongly reduced, developed as a small, narrow outgrowth at base of embolus. Abdomen 1.25 long, 0.70 wide, white, dorsal pattern as in Fig. 5. Female. Unknown.
Taxonomic remarks: See above under genus description.
Distribution: Known only from the type locality on Java, Indonesia.
Range: Javanese.
Figs 15-20.
Details of male palp structure of Javanaria gracilipes sp. nov., paratype. (15-16) Right palp, retrolateral and prolateral views, respectively. (17) Palpal tibia, paracymbium and proximal part of cymbium, dorsal view. (18) Distal part of embolus and distal suprategular apophysis, ventral view. (19) Embolic division, ventral view. (20) Distal suprategular apophysis, median membrane and embolic division, dorso-lateral view.
Javanyphia gen. nov.
Type species: Javanyphia gede sp. nov.
Diagnosis: The genus contains large-sized, linyphiine-like erigonines, with a total length of 2.3-2.4, which are characterized by the following combination of somatic and genitalic characters:
1) Carapace unmodified, eyes normal in size, cephalic pits (= sulci) absent (Figs 7-9).
2) Abdomen with a dorsal pattern (Figs 7-8).
3) Chaetotaxy formula 2.2.1.1; each metatarsus with a trichobothrium; TmI 0.78-0.82.
4) Palpal tibia modified, with a distal claw-shaped apophysis (Figs 21, 23).
5) Paracymbium relatively small.
6) Tegulum with a protegulum (Fig. 21)
7) Median membrane reduced.
8) Distal suprategular apophysis moderately developed (Fig. 25).
9) Embolus relatively short, slightly curved; radix wide, flat; convector absent (Figs 22, 25).
Etymology: The generic name is a combination of two words: “Java”, the “terra typica”, and a part of the genus name Linyphia. The gender is feminine.
Species included: Only the type species, Javanyphia gede sp. nov.
Taxonomic remarks: There are many large-sized, robust erigonines in an informal group which show the leg chaetotaxy formula 2.2.1.1 coupled with the presence of a trichobothrium on MtIV, e.g. Gnathonarium Karsch, 1881, Gongylidium Menge, 1868, Ummeliata Strand, 1942, etc. In its habitus the new genus resembles these genera, and especially Tmeticus Menge, 1868, but it has a different palp structure. The palp conformation of Javanyphia gen. nov. is characterized by a simple structure of the distal suprategular apophysis and of the embolic division, and their shapes resemble those of the Palaearctic-West Nearctic Leptorhoptrum robustum (Westring, 1851), which has the chaetotaxy formula 2.2.2.2. This similarity seems to be only a superficial resemblance, and finding a female will allow us to correctly determine the placement of the genus in the subfamily Erigoninae.
Distribution: Known only from the type locality on Java, Indonesia.
Javanyphia gede sp. nov.
Figs 7-9, 21-25
Holotype: MHNG; male [sample AS-05/11]; INDONESIA, Java, West Java Province, Gunung [= Mount] Gede Pangrango National Park, near Cibodas, 6°47′0″S, 107°01′0″E, 1450-1600 m a.s.l.; 4.-11.V.2005; leg. A. Schulz.
Paratypes: MHNG; 2 males [sample 5a]; INDONESIA, West Java Province, Mt Gede, about 50 km SE of Bogor, 2600 m a.s.l., Ericaceae forest, sifting of vegetational debris; 5.XI.1989; leg. D. Burckhardt, I. LöbI & D. Agosti.
Etymology: The specific epithet is a name in apposition referring to the place of origin, Mt Gede and its environs.
Description: Male paratype. Total length 2.30. Carapace unmodified, as shown in Figs 7-9, 1.13 long, 0.83 wide, pale brown with darkened radial strips between coxal elevations. Chelicerae 0.45 long, mastidion absent. Anterior margin of fang groove with five strong teeth, posterior margin with 4-5 small teeth. Legs pale brown to yellow, covered with numerous hairs. Leg I 3.64 long (1.00 + 0.28 + 0.93 + 0.83 + 0.60), leg IV 3.79 (1.03 + 0.30 + 0.95 + 0.98 + 0.53). Chaetotaxy 2.2.1.1. Length of spines 1-2 diameters of corresponding leg segment. Each metatarsus with a trichobothrium. TmI 0.78. Palp (Figs 21-25): Tibia with a large, claw-shaped prolateral outgrowth. Paracymbium relatively small, L-shaped, hooked apically. Tegulum subdistally with a keel-shaped outgrowth on ventral side, terminating with protegulum. Distal suprategular apophysis straight, narrow and relatively short. Median membrane reduced. Embolus short, straight and narrow. Radix small, flat and triangular. Abdomen 1.25 long, 0.75 wide, dorsal pattern as shown in Fig. 8.
Variation: The two paratypes have a different abdominal pattern: Fig. 8 cf. Fig. 9. In the holotype the pattern is similar to that in Fig. 9, but somewhat lighter. Female. Unknown.
Taxonomic remarks: See above under genus description.
Distribution: Known only from two nearby localities in West Java Province, Java, Indonesia.
Range: Javanese.
Parameioneta javaensis sp. nov.
Figs 26-31
Holotype: MHNG; male [sample JB-89/02]; INDONESIA, Java, West Java Province, 8 km N of Bandung, Taman Hutan Raya Juanda (Forest Conservation Park), Winkler extraction; 13.X.1989; leg. J. Robert.
Etymology: The specific epithet is a name in apposition referring to the island where the types of this species were collected.
Diagnosis: The new species is well distinguished by the presence of a sharp, dorsal tooth on the palpal tibia, by the absence of a pit hook (after Saaristo, 1973) on the distal suprategular apophysis, as well as by the specific shape of the paracymbium, lamella characteristica and embolus.
Description: Male holotype. Total length 1.40. Carapace unmodified, 0.65 long, 0.50 wide, greyish yellow. Eyes not enlarged, normal in size. Chelicerae 0.25 long, mastidion absent. Legs pale yellow. Leg I 2.04 long (0.53 + 0.18 + 0.53 + 0.50 + 0.30), leg IV 2.03 (0.55 + 0.13 + 0.50 + 0.50 + 0.35). Chaetotaxy 2.2.2.2. Length of spines 1-2 diameters of corresponding leg segment. Mt I-III with a trichobothrium each. TmI 0.21. Palp (Figs 26-31): Patella with a curved dorsal spine. Tibia with a small, sharp tooth dorsally. Paracymbium V-shaped, its distal part weakly sclerotized, almost transparent. Distal suprategular apophysis short and rounded, pit hook absent. Median membrane short and wide. Lamella characteristica long, widened distally and ending in two long, dark, stylet-shaped branches, upper branch with split apex. Terminal apophysis long, cylindrical, narrowing distally. Embolus with a long and narrow main body, embolus proper bifid terminally, branching off below apex of main body (Fig. 31). Abdomen 0.70 long, 0.45 wide, pale grey. Female. Unknown.
Taxonomic remarks: The new species is similar to Maorineta sulawesi Tanasevitch, 2012, described from both sexes from Sulawesi, Indonesia (Tanasevitch & Stenchly, 2012). In the description the authors pointed out that M. sulawesi is clearly distinguished from other known congeners. Indeed, the palp structure of M. sulawesi is quite different from that of other Maorineta Millidge, 1988, namely by the clearly differentiated sclerites in the embolic division, and this kind of conformation rather corresponds to Parameioneta Locket, 1982. Thus, I here transfer M. sulawesi to Parameioneta. Parameioneta javaensis sp. nov. clearly differs from P. sulawesi comb. nov. by a smaller dorsal tooth on the palpal tibia, by the absence of a pit hook, as well as by the shape of the lamella characteristica and of the embolus (Figs 30-31 cf. Tanasevitch & Stenchly, 2012: figs 11-13).
Distribution: Known only from the type locality on Java, Indonesia.
Range: Javanese.
Figs 21-25.
Details of male palp structure of Javanyphia gede sp. nov., paratype. (21-22) Right palp, retrolateral and prolateral views, respectively. (23) Palpal tibia, dorsal view. (24) Paracymbium, lateral view. (25) Distal suprategular apophysis and embolic division, ventro-lateral view.
Figs 26-31.
Details of male palp structure of Parameioneta javaensis sp. nov. (26) Right palp, retrolateral view. (27) Paracymbium, lateral view. (28) Palpal tibia, dorsal view. (29) Embolic division, ventro-lateral view. (30) Lamella characteristica, ventro-lateral view. (31) Embolus, ventro-lateral view.
FAUNISTICS
Besides the four new species described above, the spider fauna of Java contains the 16 listed below.
Caviphantes pseudosaxetorum Wunderlich, 1979
Remarks: On Java this species in known from the Cibodas Botanical Garden (1400 m a.s.l.), West Java Province (Tanasevitch, 2019b).
Range: East Asian Palaearctic - Oriental.
Ceratinopsis orientalis Locket, 1982
Remarks: On Java this species in known from the environs of Cipanas, West Java Province (Tanasevitch, 2017a).
Range: Oriental.
Ketambea permixta Millidge & Russell-Smith, 1992
Remarks: Known only from a single female from Cibodas (1600 m a.s.l.), West Java Province, Indonesia (Millidge & Russell-Smith, 1992).
Range: Javanese.
Ketambea vermiformis Millidge & Russell-Smith, 1992
Remarks: Known from specimens of both sexes from Cibodas, West Java Province, Indonesia (Millidge & Russell-Smith, 1992).
Range: Javanese.
Metalepthyphantes kraepelini (Simon, 1905)
Material examined: MHNG; 1 female [sample AS-05/11]; INDONESIA, Java, West Java Province, Gunung Gede Pangrango National Park, near Cibodas, 6°47′0″S, 107°01′0″E, 1450-1600 m a.s.l.; 4.-11.V.2005; leg. A. Schulz.
Remarks: This species was originally described under Bathyphantes Menge, 1866 from a single female. Later the holotype was re-described and illustrated, and the species transferred to Metalepthyphantes Locket, 1968 by Helsdingen (1985b). Known only from West Java Province, Indonesia (Simon, 1905 and present new record).
Range: Javanese.
Mitrager noordami Helsdingen, 1985
Remarks: This species was described from specimens of both sexes from Central Java Province, Indonesia, as the type species of the genus Mitrager Helsdingen, 1985 (Helsdingen, 1985a). In its somatic and genitalic characters the genus is very similar to Oedothorax Bertkau, in Förster & Bertkau, 1883. This similarity is based on the same chaeto- and trichobothriotaxy, highly modified male carapace, the male palp conformation, notably by the shape of the embolus and the presence of a convector (named “lamella” by the author of the original description) in the embolic division. The epigyne structure also is very similar to that of Oedothorax representatives. The species is known only from the Dijeng Plateau (2580 m a.s.l.), Central Java Province, Indonesia (Helsdingen, 1985a).
Range: Javanese.
Nasoona asocialis (Wunderlich, 1974)
Walckenaeria caobangensis Tu & Li, 2004, syn. nov.
For other synonyms and combinations see World Spider Catalog (2019).
Remarks: Nasoona asocialis was described from a female from the Nepal Himalayas and originally placed in Oedothorax (Wunderlich, 1974). Later this species was described for a second time from a single male as Gorbothorax ungibbus Tanasevitch, 1998 from the same mountain region (Tanasevitch, 1998). The species is widely distributed in the Oriental Region: China, Nepal, India, Myanmar, Laos, Thailand, Malaysia (mainland), Indonesia (Bali, Java) (World Spider Catalog, 2019). Walckenaeria caobangensis was described on the basis of a female from Cao Bang Province, northern Vietnam (Tu & Li, 2004). The original description and figures of carapace, epigyne and vulva clearly show that W. caobangensis is conspecific with Nasoona asocialis and therefore a junior synonym. The synonymy is indirectly supported by the fact that N. asocialis is known from Xishuangbanna, southern China (Zhao & Li, 2014) and from northern Laos (Tanasevitch, 2014), territories close to the type locality of W. caobangensis. The species in known on Java from the Ijen Mts, 950 m a.s.l. (Tanasevitch, 2017a).
Range: Oriental.
Nematogmus dentimanus Simon, 1886
Remarks: On Java this species is known from Buitenzorg (= Bogor), West Java Province (Helsdingen, 1979).
Range: Oriental.
Neriene amiculata (Simon, 1905)
Remarks: This species was described under Linyphia Latreille, 1804 from specimens of both sexes from Cibodas (= Tjibodas), West Java Province, Indonesia (Simon, 1905). Later the types were re-described and the species transferred to Neriene Blackwall, 1833 by Helsdingen (1969). Known only from Java so far.
Range: Javanese.
Neriene macella (Thorell, 1898)
Remarks: On Java this species is known from the Cibodas Botanical Garden (1250-1300 m a.s.l.) (Tanasevitch, 2017a).
Range: Oriental.
Neriene sundaica (Simon, 1905)
Remarks: This species was described under Linyphia from a single female from Lombok, Indonesia and from a single male from Cibodas (= Tjibodas), West Java Province, Indonesia (Simon, 1905). Later the types were re-described and the species transferred to Neriene by Helsdingen (1969).
Range: South Indonesian.
Oedothorax bifoveatus Tanasevitch, 2017
Remarks: On Java this species is known from the Cibodas Botanical Garden (1400 m a.s.l.) and from the environs of Cibodas (1450-1600 m a.s.l.) (Tanasevitch, 2017b).
Range: Oriental.
Ostearius melanopygius
(O. Pickard-Cambridge, 1880)
Remarks: On Java this species is known from the Cibodas Botanical Garden (1320 m a.s.l.) (Tanasevitch, 2019b).
Range: Cosmopolitan.
Piesocalus javanus Simon, 1894
Remarks: This species is known only from a single female from Palabouan, Java (Simon, 1894; Jocqué, 1983).
Range: Javanese.
Racata grata Millidge, 1995
Remarks: On Java this species is known from the environs of Cibodas, West Java Province (Tanasevitch, 2019a).
Range: South Indonesian.
Solenysa sp.
Material: MHNG; 1 male [sample AS-05/11]; INDONESIA, Java, West Java Province, Gunung Gede Pangrango National Park, near Cibodas, 6°47′0″S, 107°01′0″E, 1450-1600 m a.s.l.; 4.-11.V.2005; leg. A. Schulz.
Remarks: This species is a probably new and similar to Palaearctic congeners. It is characterized by a long, ribbon-shaped, distally darkened radical apophysis. The shape and the position of this sclerite strongly resembles the micronetine's lamella characteristica and it was incorrectly named so by authors who described species in this genus, e.g. Tu & Li (2006), Tu & Hormiga (2011), Wang et al. (2015), etc.
Range: Javanese.
DISCUSSION
The linyphiid spider fauna of Java is presently known to contain 20 species, 13 of them are Erigoninae, five species are Linyphiinae and two are Micronetinae. The placement of two Javanese species described under Ketambea Millidge & Russell-Smith, 1992 in the subfamily Linyphiinae is doubtful. The authors pointed out that based on the structure of the embolic division Ketambea is very similar to the Neotropical Dubiaranea Mello-Leitão, 1943 (see Millidge & Russell-Smith, 1992), the type genus of the subfamily Dubiaraneinae. However, the epigyne of Ketambea is of the Linyphiinae type, and Millidge & Russell-Smith (1992) listed it in the Linyphiinae, noting that the genus “should probably be regarded as forming part of the Linyphiinae (sensu stricto), despite the absence of the genital socket.” My opinion on the subfamily placement of the genera mentioned above is briefly given in Tanasevitch (2019a).
Among the 20 known linyphiid species from Java, eleven species were described from the island and since them have never been recorded from anywhere else. There are: Javagone maribaya sp. nov., Javanaria gracilipes sp. nov., Javanyphia gede sp. nov., Ketambea permixta, K. vermiformis, Metalepthyphantes kraepelini, Mitrager noordami, Neriene amiculata, Piesocalus javanus, Parameioneta javaensis sp. nov., and Solenysa sp. Nevertheless these species should not yet to be considered as endemics since the fauna of Southeast Asia is still insufficiently studied. Three species, Neriene sundaica, Oedothorax bifoveatus and Racata grata, were also recorded from neighboring islands: Lombok, Borneo and Krakatoa, respectively. Three species, Ceratinopsis orientalis, Nasoona asocialis and Nematogmus dentimanus, are widely distributed in the Indo-Malayan Region, and have an Oriental range. One species, Ostearius melanopygius, is a cosmopolitan which is known from all regions except for the Neotropics.
Today we can characterize the Javanese linyphiid spider fauna as Oriental, with weak relations to the East Asian Palaearctic fauna, and without any yet recognizable relations to the rich linyphiid fauna of the neighboring Australian Region.
ACKNOWLEDGEMENTS
I am deeply grateful to Peter Schwendinger (MHNG) for offering the opportunity to work on the arachnological collections under his care and for editing this paper. Thanks also go to Shou-Wang Lin (Taiwan) who kindly reviewed the manuscript.
This study was supported in part by the Presidium of the Russian Academy of Sciences, Program No. 41 “Biodiversity of natural systems and biological resources of Russia”.
