Species of the fungivorous genus Psalidothrips Priesner from China, with five new species (Thysanoptera, Phlaeothripidae)

Abstract An identification key and review is provided of fifteen species of the fungivorous genus Psalidothrips Priesner from China, with five new species, P. angustus sp. n., P. comosus sp. n., P. fabarius sp. n., and P. latizonus sp. n., and P. nigroterminatus sp. n. In addition, Psalidothrips consimilis Okajima, previously known only from Ryukyu Islands, Japan, is newly recorded in China.


Introduction
Psalidothrips Priesner is one of the most common phlaeothripine genera in tropical and subtropical regions. The members of the genus are fungus-feeders, and are particularly associated with leaf litter, their body and wing form probably being an adaptation to such habitats (Mound 1970;Okajima 1983). The genus appears to be derived from 2 Abdominal tergites III to VII each with one pair of simple wing-retaining setae; antennal segment IV with 2-4 sense cones; abdominal tergite II concolourous with the other tergites; pelta trapezoidal or broadly hat-shaped; postocellar setae much shorter than hind ocellus; male pore plate transversely long oval (Fig. 78)  Antennal segments I-II pale brown, III-VIII gradually from yellow to pale brown towards apex; abdominal tergite II darker than other tergites; male pore plate broad and arched, reaching to lateral margins (Fig. 70) ..... latizonus sp. n. 5 Antennal segments I-II and VI-VIII brown, other segments yellow; postocellar setae slightly longer than hind ocellus; postocular setae slightly longer than eyes and pointed at apex; antennal segments IV-VI not globular; male pore plate narrow and slightly arched (Fig. 73) ....................... chebalingicus -Antennal segments I and basal half of II light brown, segment III yellow, IV-VIII yellowish brown, gradually darkened distally; postocellar setae twice as long as hind ocellus; postocular setae approximately 1.5 times longer than eyes, blunt or weakly expanded at apex; antennal segments IV-VI globular; male pore plate arched with a projection medially (Fig. 69)  Postocular setae blunt apically; antennal segment VIII longer than segment VII; pelta irregularly trapezoidal without campaniform sensilla; male pore plate slightly arched (Fig. 77)  Antennal segment VIII as long as or shorter than segment VII, segments III and IV slender, not globular; male pore plate arched and complete (Fig. 71) ....ascitus

Psalidothrips amens Priesner
Psalidothrips amens Priesner, 1932: 62. Comments. This is the type species of the genus, and was based on a single female from Java, Indonesia. It belongs to the group that have antennal segments III-IV each with three sense cones. Two females listed here are identified as P. amens based on the original description and the key in Mound (1970). Wang et al. (2007) mentioned that a single male of P. amens was recorded from Hainan, China. We examined that slide-mounted specimen, labelled as the male of P. amens by Wang et al. (2007), and consider that it represents the male of P. latizonus sp. n., described below. In China, P. amens is found, so far, only from Hainan. Distribution. China (Hainan); Indonesia (Java).  Description. Female macropterous (Fig. 1). Head and antennae brown (but basal third of segment III paler), pronotum pale brown; mesonotum, abdominal segment II and sides of tergites III-VIII brown; the rest of body yellow or yellowish brown; fore wings greyish brown but paler medially.

Psalidothrips angustus
Head almost as long as broad; dorsal surface smooth, faintly sculptured posteriorly; cheeks almost straight and constricted behind eyes. Eyes approximately one-third of head length; postocular setae much longer than eyes, expanded at apex (Fig. 29); postocellar setae fine and acute, longer than diameter of hind ocellus. Antennae 8-segmented (Fig. 36), somewhat moniliform, surface without sculpture; segment III vasiform and IV-V globular, segment VIII longer than segment VII; segments III-IV with three and four sense cones respectively, sense cones usually long and thick, those on segment IV usually longer than half of the segment. Maxillary stylets reaching approximately half way to postocular setae and placed far apart, often V-shaped.
Pelta hat-shaped with flat anterior margin, faintly reticulate medially, a pair of campaniform sensilla present (Fig. 34). Abdominal tergites II-VII with two pairs of weakly sigmoid wing-retaining setae; tergite IX setae S1 subequal to tube in length and shorter than S2; S2 slightly longer than tube, both pointed at apex (Fig. 35).
Measurements ( Male macropterous (Fig. 2). Similar in colour and structure to female, but body smaller; fore tarsal tooth present (Fig. 33); pore plate on abdominal sternite VIII disconnected and slightly arched (Fig. 67); abdominal tergite IX setae S1 as long as tube and longer than S2.
Etymology. The specific epithet, angustus, is from the Latin adjective, meaning narrow and refers to the narrow pore plate.

Comments.
This new species appears to be closely related to P. comosus sp. n., by sharing moniliform antennae and antennal segments III-IV with three and four sense cones, and the fore tarsal tooth present in female. However, it differs from the latter by the following characteristics: (1) the surface of antennae is without sculpture (apical half of antennal segments III-VII with lines of sculpture in comosus ); (2) postocular setae with expanded apex (whereas comosus with pointed postocular setea); (3) abdominal tergites II to VII each with two pairs of wing-retaining setae (only one pair of wing-retaining setae on these segments in comosus ); (4) male's pore plate on abdominal sternite VIII narrow and slightly arched, occasionally disconnected (whereas pore plate with wider band which reaches lateral margins in comosus). Fig. 12 Psalidothrips armatus Okajima, 1983: 6.  Comments. This species (Fig. 12) belongs to the group in which the fore tarsus is armed with a tooth in both sexes. Wang et al. (2007) recorded a male of this species in Hainan, China. In this study, we examined the male specimen labelled as P. armatus by Zhang and Tong (1997) and considered that this single male specimen seems to be an unknown species which is similar to the male of P. angustus sp. n. or P. longidens. In China, this species so far is only recorded in Hainan.

Psalidothrips ascitus (Ananthakrishnan) Figs 13-14, 71
Callothrips ascitus Ananthakrishnan, 1969: 176. Psalidothrips ascitus (Ananthakrishnan): Okajima, 1983: 6. Comments. This species is found widely across the tropical and subtropical areas of China, also in other parts of the world. It is most closely related to P. lewisi (Bagnall). Their males are difficult to distinguish from each other as their pore plates are very similar in shape (Figs 14, 71, 76), but the females can be distinguished from those of P. lewisi by the length of the postocellar setae that are usually as long as the diameter of an ocellus or shorter, and the colour of the antennae and head that are almost uniformly brown ( Fig. 13) (Okajima 2006). However, these two species were always collected together at the same sampling sites from leaf litter. Overall, in structure these two species are very similar to each other and the possibility exists that they may represent a single, widespread species. Distribution. China (Hubei, Guizhou, Hunan, Jiangxi, Yunnan, Guangdong, Hainan, Taiwan); Japan; Malaysia; India. 72 Psalidothrips bicoloratus Wang, Tong & Zhang, 2007: 28. Comments. This species is very similar to P. amens in general appearance. However, it is distinguished from the latter by the following characters: head and antennal segments I-II, V-VIII brown, rest of body yellow ( Fig. 15-16); postocular setae shorter than eyes, cheeks straight and weakly constricted behind eyes.

Psalidothrips chebalingicus Zhang & Tong
Figs 17-18, 62-66, 73 Psalidothrips chebalingicus Zhang & Tong, 1997: 87. Diagnosis. This species was originally described in Chinese with the male as holotype (Zhang & Tong 1997). Unfortunately, in original paper the illustrations were distorted by compression in the process of printing and the female was described very briefly, which meant that the female of P. chebalingicus could be confused with other similar species. The diagnosis is emended as follows: Female macropterous (Fig. 17). Body yellow except head, antennal segments I-II and VI-VIII (Fig. 66), margins of pterothorax brown; abdominal tergite II brown with median portion yellow; antennal segments III-V yellowish brown but gradually dark- ened distally. Head (Fig. 62) slightly wider than long, dorsal surface smooth; cheeks weakly swollen and constricted just behind eyes; postocellar setae slightly longer than hind ocellus; postocular setae slightly longer than eyes and pointed at apex. Antennae 8-segmented (Fig. 66), surface without sculpture; segments III-IV each with two sense cones; segment VIII slightly longer than segment VII. Maxillary stylets reaching approximately half distance to postocular setae and far apart, V-shaped. Pronotum dorsal surface smooth, am and aa minute, ml apex blunt, epim and pa pointed at apex (Fig. 63). Fore tarsal tooth absent. Pelta hat-shaped, weakly sculptured on anterior half, with a pair of campaniform sensilla posteriorly (Fig. 64); abdominal tergites II-VII with two pairs of weakly sigmoid wing-retaining setae; abdominal tergite IX setae S1 subequal to tube in length (Fig. 65), setae S2 longer than tube, both S1 and S2 pointed at apex.
Male macropterous (Fig. 18). Similar in colour and structure to females, but body smaller; fore tarsal tooth present; pore plate on abdominal sternite VIII narrow and slightly arched medially (Fig. 73); abdominal tergite IX setae S1 slightly shorter than tube but much longer than S2.
Comments. This species is somewhat similar to P. ascites in colour and structure. However, it can be distinguished from the latter by the following main features: antennal segments III-IV each with two sense cones; pore plate on abdominal sternite VIII located medially, not reaching lateral margin.

Psalidothrips comosus
Description. Female macropterous (Fig. 3). Body yellow except for head, anterior and lateral margins of pterothorax, abdominal segment II dark brown; abdominal tergites III-VIII yellow with light brown shadings laterally; tube yellow with light brown basally. Wings shaded with greyish brown.
Head (Fig. 37) wider than long, faintly sculptured on posterior margin; cheeks almost straight or slightly widened towards base, but constricted behind eyes; eyes approximately 1/3 of head length; postocellar setae long and acute, approximately 1.5-2.0 times longer than the diameter of hind ocellus; postocular setae long and acute, approximately 2.0 times longer than eyes. Antennae 8-segmented (Fig. 44) and slightly moniliform, apical half of antennal segments III-VII with lines of sculpture; segment III vasiform, IV-V globular, segment VIII distinctly longer than segment VII; segments III-IV with 3 and 4 sense cones respectively. Maxillary stylets reaching approx. half way to postocular setae and wide apart. Pronotum (Fig. 38) broad, surface smooth with a weak median longitudinal line; three pairs of major setae (ml, epim, pa) well developed, elongate and acute, aa setae fine and long, slightly shorter or subequal to interocular setae in length. Mesopresternum eroded with small irregular sclerites laterally. Fore wing sub-basal setae S1 shortest, S2 longer than S3. Fore tarsal tooth present (Fig. 39).
Pelta irregularly hat-shaped (Fig. 41), sculptured on anterior half, campaniform sensilla absent in holotype. Abdominal tergites II to VII each with one pair of straight wing-retaining setae (Fig. 42); tergite IX setae S1 and S2 long and acute, setae S1 as long as or slightly longer than S2, setae S2 longer than tube; tube slightly longer than head.
Female apterous. Similar to macropterous female in structure, but eyes smaller, approximately 1/4 of head length; postocellar setae approximately 2.5-3.5 times longer than diameter of hind ocellus; postocular setae elongate and acute, approximately 2.5 times longer than eyes.
Etymology. Specific epithet from Latin comosus which means long haired, and refers to the new species having relatively long body setae.

Distribution. China (Guangdong).
Comments. This new species is similar to P. taylori Mound & Walker from Australia and New Zealand in sharing the elongate postocular setae, distinct pronotal aa setae, and only one pair of wing-retaining setae on abdominal tergites (Mound and Walker 1986). However, it can be readily distinguished from the latter by the antennal segments III-VII with lines of sculpture, segments III-IV with three and four sense cones respectively, and a fore tarsal tooth present in both sexes. Campaniform sensilla are absent from the pelta of the holotype, but are present on the pelta of paratypes from the same population. This new species is also similar to the new species, P. angustus, as discussed above.

Psalidothrips consimilis Okajima Figs 19-20, 74
Psalidothrips consimilis Okajima, 1992 Distribution. China (Guangdong); Japan (Ryukyu Islands). Comments. Described originally from Ryukyu Islands, Japan (Okajima 1992), this thrips is here newly recorded from China. In the description (Okajima 1992), the postocellar setae are minute, usually shorter than the diameter of the hind ocellus, but in the specimens listed here these setae are variable in length: some of them are much longer than the hind ocellus. The female (Fig. 19) is very similar to that of P. ascites (Okajima 1992(Okajima , 2006. However, the males (Fig. 20) can be easily distinguished from P. ascitus by the narrow and incomplete pore plate on abdominal sternite VIII (Fig. 74).

Psalidothrips elagatus Wang, Tong & Zhang Figs 21-22, 75
Psalidothrips elagatus Wang, Tong & Zhang, 2007: 26. Comments. Wang and Tong (2007) stated that this species has two sense cones on antennal segment III, but re-examination of the type material has found this segment to have three sense cones, although the ventral one is small and short. Therefore, P. elagatus belongs to the group that have antennal segments III and IV each with three sense cones. This species (Figs 21-22) is similar to P. bicoloratus, but can be distinguished by the key above.
Distribution. China (Guangdong).   (Fig. 5). Body yellow except head, mesothorax, abdominal tergite II brown, the rest of body yellow. Antennal segments I and basal half of II light brown, segment III yellow, IV-VIII yellowish brown gradually darkened distally. Wings shaded with greyish brown but paler medially.

Description. Female macropterous
Head (Fig. 45) almost as long as wide, dorsal surface smooth, faintly sculptured at base; cheeks weakly swollen, slightly constricted just behind eyes. Eyes one-third as long as head; postocular setae approximately 1.5 times longer than eyes and weakly expanded at apex; postocellar setae approximately twice as long as hind ocellus or longer. Antennae 8-segmented, somewhat moniliform, surface without sculpture (Fig.  49); segment VIII longer than segment VII; segments III and IV each with two sense cones. Maxillary stylets reaching about one-third way to postocular setae and wide apart, often V-shaped.
Pronotum (Fig. 46) broad, surface smooth with a weak median longitudinal line; pronotal am and aa minute, the other three pairs of major setae well developed, pa longest, ml slightly longer than epim, epim and pa pointed, but ml expanded at apex. Fore tarsal tooth absent. Sub-basal wing seta S1 minute, S2 longer than S3, both pointed at apex.
Pelta nearly bell-shaped with short lateral lobes (Fig. 47), anterior half distinctly sculptured, a pair of campaniform sensilla present. Abdominal tergites II-VII with two pairs of simply curved wing-retaining setae; S1 and S2 on tergite IX subequal in length (Fig. 48), slightly shorter than tube, all pointed at apex; basal width of tube approximately 3.0 times wider than apical width; anal setae much shorter than tube.
Male apterous (Fig. 6). Similar to female in structure and colour, but smaller and fore tarsus armed with a tooth; setae S2 much shorter than S1 on abdominal tergite IX; abdominal sternite VIII pore plate arch-shaped with a projection medially (Fig. 69).
Distribution. China (Guangdong). Etymology. The specific epithet, fabarius, is from the Latin word meaning beadlike, referring to the moniliform antennal segments.
Comments. This new species appears to be most similar in appearance to P. ochraceus Okajima from Ryukyu Islands, Japan, particularly in having two sense cones on antennal segments III and IV, and the elongate postocellar setae, but it can be readily distinguished from the latter by the following characteristics: (1) postocular setae expanded at apex (pointed in ochraceus); (2) pronotal ml setae expanded at apex (ml pointed in ochraceus); (3) pelta distinctly sculptured on anterior half (whereas pelta indistinctly sculptured in ochraceus); (4) abdominal tergite IX setae S1 and S2 subequal in length, but shorter than tube (whereas in ochraceus, S1 slightly shorter than tube, S2 longer than tube); (5) three sub-basal wing setae present on fore wing (only one minute sub-basal wing seta present in ochraceus). Female macropterous (Fig. 7). Head largely yellow or yellowish brown with dark brown margins; mesonotum yellowish brown with dark brown margin, abdominal tergite II brown, darker than other tergites, abdominal segments yellow shaded with pale brown laterally, the rest of body yellow. Antennal segments I-II pale brown, III-VIII shading gradually from yellow to pale brown towards apex. Wings shaded with greyish brown but paler medially.

Psalidothrips latizonus
Head (Fig. 50) almost as long as broad, dorsal surface smooth with a few lines of sculpture posteriorly; cheeks slightly swollen and constricted just behind eyes. Eyes approximately one-third of head length; postocellar setae approximately 2.5 times longer than hind ocellus; postocular setae bluntly acute, as long as or slightly longer than eyes . Antennae 8-segmented (Fig. 54), surface without sculpture; segments III and IV each with two sense cones, segment VIII longer than segment VII. Maxillary stylets short and wide apart, often V-shaped.
Pronotum about 0.8 times as long as head, almost smooth (Fig. 51); ml and epim subequal in length, pa longest, all bluntly acute. Fore tarsal tooth absent. Fore wing sub-basal wing seta S1 minute, S2 longer than S3, both pointed at apex.
Pelta nearly hat-shaped (Fig. 52), faintly sculptured, with a pair of campaniform sensilla. Abdominal tergites II to VII each with two pairs of sigmoid wing-retaining setae; tergite IX setae S1 shorter than S2 which slightly longer than tube (Fig. 53); basal width of tube 3-4 times wider than apical width.
Male macropterous (Fig. 8). Similar in colour and structure to female except for fore tarsal tooth present and setae S1 slightly longer than S2 on abdominal tergite IX; pore plate on abdominal sternite VIII broadly arched (Fig. 70).
Measurements ( Etymology. The specific epithet, latizonus, is from the Latin adjective meaning broad band, in reference to the broad male pore plate. Comments. The new species is closely similar to P. chebalingicus in general appearance, but differs from it as follows: head largely yellowish brown but darkened laterally (head uniformly brown in chebalingicus); antennal segments I-II pale brown, III-VIII shading gradually from yellowish brown to pale brown towards apex (antennae yellow except segments I-II and VI-VIII brown in chebalingicus); postocellar setae about 2.5 times as long as hind ocellus (postocellar setae slightly longer than hind ocellus in chebalingicus); antennal segment VIII longer than segment VII (antennal segment VIII as long as segment VII in chebalingicus). Moreover, the males have the broad pore plate reaching the lateral margin of sternite VIII, whereas the pore plate of P. chebalingicus is narrow and slightly arched, not reaching the lateral margin.

Psalidothrips lewisi (Bagnall) Figs 23-24, 76
Trichothrips lewisi Bagnall, 1914: 30. Psalidothrips alaris Haga, 1973: 76. Synonymised by Okajima and Urushihara 1992 167. Psalidothrips lewisi (Bagnall): Okajima and Urushihara 1992: 167. Comments. This species has a wide geographical range from Shandong province to Hainan province in China. The Chinese specimens listed here have been compared with the Japanese specimens (provided by S. Okajima) and, despite antennal segments III-VIII of the Japanese specimens being almost uniformly yellow and much paler than the Chinese specimens (Figs 23-24), they are considered to represent P. lewisi. Moreover, the macropterous form in both sexes is more common than the apterous form among the Chinese specimens.
Distribution. China (Shandong, Guizhou, Hunan, Jiangxi, Yunnan, Guangdong, Hainan); Japan. 77 Psalidothrips longidens Wang, Tong & Zhang, 2007: 30. Comments. This species belongs to the group in which the fore tarsal tooth is present in both sexes (Figs 25-26). The following characters can distinguish it from congeneric species: antennal segments III and IV each with three sense cones; fore tarsus of females armed with a long and strong tooth, pelta irregularly rectangular without campaniform sensilla, and male with a transverse and weakly curved pore plate (Fig. 77   Female macropterous (Fig. 9). Body largely yellow, head yellow tinged with light brown anteriorly, abdominal segments shading gradually from yellow to yellowish brown towards tube; antennal segments I-III yellow, IV-VIII dark brown. Wings shaded greyish brown but paler medially.

Psalidothrips longidens Wang, Tong & Zhang
Head (Fig. 55) wider than long, faintly sculptured on posterior margin; cheeks slightly swollen and constricted behind eyes; eyes approximately 2/5 of head length; postocellar setae long and acute, approximately 2.5 times longer than diameter of hind ocellus; postocular setae blunt or weakly expanded at apex, as long as or slightly longer than eyes. Antennae 8-segmented (Fig. 61) ments III and IV each with two sense cones, segment VIII shorter than segment VII. Maxillary stylets reaching about half way to postocular setae and wide apart.
Pronotum broad (Fig. 56), surface smooth with a median longitudinal line; three pairs of major setae well developed, pa longest and acute at apex; ml subequal to epim in length, both slightly expanded apically. Fore tarsal tooth absent. Sub-basal wing seta S1 minute, S2 longer than S3, both pointed at apex. Mesonotum weakly sculptured on anterior third; metanotum smooth with longitudinal sculpture laterally. Mesopresternum complete and boat-shaped (Fig. 57).
Pelta (Fig. 58) hat-shaped with a pair of campaniform sensilla posteriorly, surface sculptured on anterior half. Abdominal tergites II to VII each with two pairs of wingretaining setae; tergite IX setae S1 and S2 pointed (Fig. 60), S1 shorter than S2 which are subequal to tube in length; basal width of tube approximately 2.5 times wider than apical width.
Distribution. China (Yunnan, Hainan). Etymology. The species name is an arbitrary combination of two Latin adjectives, niger meaning black and terminatus meaning terminal, in reference to the antennae with dark brown distal segments.
Comments. The new species belongs to the group in which antennal segments III and IV both have two sense cones. It can be distinguished from the other members of the group by the following combination of features: (1) body largely yellow but antennal segments IV-VIII dark brown; (2) mesopresternum complete and boat-shaped; (3) pronotal posteroangular setae acute at apex and much longer than other major pronotal setae; (4) abdominal tergite II concolourous with the other tergites, and (5) male pore plate arched but slightly straight anteriorly. 78 Psalidothrips simplus Haga, 1973: 77. Comments. This species (Figs 27-28) is easily separated from congeneric species by the following combination of characters: body largely yellowish brown, abdominal tergite II almost concolourous with other tergites; abdominal tergites III to VII each with one pair of simple wing-retaining setae; pelta broad hat-shaped or trapezoidal and male with a transversely long oval pore plate (Fig. 78). Okajima (2006) pointed out that antennal segment III always has two sense cones, but those on segment IV are variable in number from two to four, which is the same in the Chinese specimens.