Revision of the genus Salganea Stål (Blattodea, Blaberidae, Panesthiinae) from China, with descriptions of three new species

Abstract Three new species of Salganea Stål, 1877 are described and illustrated: S. quinquedentata sp. n., S. anisodonta sp. n. and S. flexibilis sp. n. S. taiwanensis Roth, 1979, S. guangxiensis (Feng & Woo, 1990), S. incerta (Brunner von Wattenwyl, 1893) and S. raggei Roth, 1979 are redescribed. Panesthia concinna Feng & Woo, 1990 is synonymized with S. taiwanensis Roth, 1979 and Panesthia guangxiensis Feng & Woo, 1990 is transferred to the genus Salganea for the first time. As well, a key to species from China is presented.


Introduction
The blaberid genus Salganea belongs to the subfamily Panesthiinae (tribe Salganeini), which is subsocial and xylophagous. Some members live in biparental families (Maekawa et al. 2005), where their young nymphs are defended and fed by parents (Maekawa et al. 2008). They are heavy bodied insects ranging from 15.5 to >60 mm in length and the pronotum of the two sexes is usually similar (Maekawa et al. 2008), which can result in a substantial ecological impact on the decomposition of logs (Bell et al. 2007).
This genus is recognized by its T6 with lateral margin even, T7 with lateral margin serrated, and holes associated with setae in the anterolateral corners of abdominal terga. Princis (1965) listed 22 species of Salganea worldwide. Bey-Bienko (1957) listed 3 species of Salganea from Sichuan and Yunnan Provinces, China, 2 of which, S. amboinica (Brunner von Wattenwyl, 1893) and S. morio (Burmeister, 1838), probably referred to S. taiwanensis and S. raggei respectively (Roth 1979). Roth (1979) reported 42 species and 4 subspecies in this genus, 3 species of which were from China. In addition, he erected 5 species-groups, based on the anterior margin of the pronotum and male genital phallomere L2d, i.e., the papua species-group, the foveolate species-group, the raggei species-group, the morio species-group and the nigrita species-group, although the molecular analysis result did not conform to this conclusion completely (Maekawa et al. 2001). Asahina (1988) considered that S. taiwanensis was composed of two subspecies on the basis of the body size, male genital phallomere L2d and on distribution as well. But according to the molecular phylogeny and geographic distribution of wood-feeding cockroach genera Salganea Stål, 1877 and Panesthia Serville, 1831 in East Asia Islands, Maekawa et al. (1999a) did not agree with the subspecies designations of Asahina. Maekawa et al. (1999b) described one species and then described one species, providing the phylogenetic tree for 27 species and 3 subspecies of the genus Salganea in 2005. Up to now, there are 47 species and 6 subspecies recognized worldwide (Beccaloni 2007), of which 5 species are from China.
Herein, we redescribe Salganea, describe 3 new species from China, redescribe 4 species and give a key to the Chinese species. After the examination of type specimens, Panesthia concinna Feng & Woo, 1990 is synonymized with Salganea taiwanensis and Panesthia guangxiensis Feng & Woo, 1990 is transferred to the genus Salganea.

Materials and methods
The terminology of the head, body and male genitalia used in this paper mainly follows Roth (1977Roth ( , 1979, and the terminology of veins follows Rehn (1951). Measurements were based on material examined, and the measurement of body length was without the tegmen. CV total is the coefficient of variation of total number of veins which without radius and anal veins (Liang et al. 2012). The genital segments of the examined specimens were macerated in 10% NaOH and observed in glycerin jelly using a Motic K400 stereomicroscope. All drawings were made with the aid of a Motic K400 stereomicroscope. Photographs of the specimens were made using a Canon 50D plus a Canon EF 100mm f/2.8L IS USM Macro lens with the aid of the Helicon Fo-cus software. The type specimens are deposited in the Insect Collection of Southwest University, Beibei, Chongqing, China (SWU) and the Museum of Hebei University, Baoding, Hebei Province, China (HBU).
Generic diagnosis (modified after Roth (1979)). Vertex rarely foveolate (except S. papua and S. mandelsi) and exposed. Pronotum transversal ovate, anterior margin almost straight or slightly convex, lateral margins arched, hind margin almost straight; anterior half depressed, with a pair of curved, oblique grooves; posterior half elevated and punctate. Tegmina and wings fully developed, sometimes mutilated, or reduced, or tegmina reduced but wings absent, or both tegmina and wings absent. If tegmina and wings fully developed, tegmina usually narrow and leathery with base thickened, the humeral area well developed and punctate, anterior margin slightly curved medially, subcostal vein short and unbranched. Hind wings with anal area developed with border smooth and rounded; subcostal vein (Sc) straight and simple or with a small branch at apical part, extending beyond the midline of wing length; radial vein (R) with less than five branches, with or without apical posterior branch (Ap. Post. Br.); median vein (M) simple, rarely with a terminal twigging; cubitus (Cu) with more than 8 branches, at least half of which are incomplete and fuse apically or going to the first plical vein (1Pl). Lateral margin of the 6 th abdominal tergum (T6) straight; lateral margin of the 7 th abdominal tergum (T7) uneven, caudal angles produced caudally or laterocaudally; anterolateral corners of 6 th and 7 th abdominal terga usually with holes, sometimes holes also existing in the corners of T3, T4 or T5, which are usually accompanied with small setae or hairs. Abdominal sternites punctured, the last sternite with a marginal ridge extending along the lateral margins. Supra-anal plate transverse; paraprocts broad, left one in ventral view armed with a finger-like projection, which is curved dorsally and whose apex is sclerotized. Subgenital plate flabellate, anterior margin straight or concave, lateral margins oblique, hind margin round. Four genital phallomeres as below: first sclerite of left phallomere (L1) plate-like, well developed but usually not sclerotized, sometimes reduced or absent; second ventromedial sclerite of left phallomere (L2vm) rod-like; second dorsal sclerite of the left phallomere (L2d) elongate, variable; second sclerite of right phallomere (R2) hook-shaped, reduced or absent in some species.
Remarks. Because the irregularities on lateral margin of T7 maybe subobsolete, this genus is similar to Panesthia. With a notch existing anterior to the laterocaudal angle of T7 sometimes, this genus resembles Ancaudellia Shaw, 1925. But it can be distinguished by the following characteristics: 1) anterolateral corners of 6 th and 7 th abdominal terga usually with holes and holes associated with well spaced setae (Panesthia rarely with holes and without setae, Ancaudellia with grooves and associated with dense patches of contiguous setae); 2) lateral margin of S7 with a ridge extending from anterior margin to hind margin (with a feeble and short ridge, or without a ridge in Panesthia and Ancaudellia).
Although S. amboinica, S. morio and S. passaloides passaloides (Walker, 1868) were recorded from China, none of them were found after our wide survey of collecting and examining loans from other museums. Moreover, Roth (1979) had questioned whether they were truly recorded from China. These species have been excluded in our count for the total number of species in this genus from China, and have been removed from our key to the Salganea from China.
Distribution. Few places of Palaearctic Region (China, Japan), Oriental Region, Australian Region.
-Pronotum without tubercles (Fig. 25), hind margin of supra-anal plate with 5 relatively slender teeth, sometimes fused together or with small acute spines between them (Fig. 28)  Lateral margin of T7 with 5-6 obtuse teeth (Fig. 62), hind margin of supraanal plate with 8-16 subequal teeth (Fig. 64) (Fig. 70), hind margin of supraanal plate with 8 unequal teeth (Fig. 72) (Fig. 2). Vertex and face punctate, the former exposed. Anterior margin of pronotum smooth, or weakly concave; anterior half of pronotum slightly depressed, the floor punctured, denser laterally; posterior half punctured sparsely and almost evenly, without tubercles ( Fig. 21). Tegmina and wings well developed, extending beyond end of abdomen, sometimes mutilated (Fig. 1). Radius of tegmen with a long apical posterior branch, which has accessory branches, or apical posterior branch absent; median vein is simple or branched . Radial vein of hind wing with posterior branch medially; median vein branched terminally or not; cubitus with 4-5 complete and 5-6 incomplete branches . Anterior ventral margin of front femur with 1-3 spines and a small distal spine, hind margin with a large distal spine. Abdominal tergites punctured, the punctures denser laterally and caudally; T5-T7 with gradually increased holes on the anterolateral corners, minute sparse hairs sometimes visible on the surfaces; caudal angles of T6 weakly explored; lateral margins of T7 slightly uneven, caudal angles oblique, large and tapering (Fig. 22). Abdominal sternites densely punctured, the punctations larger and denser caudally; hind margin of the last sternite entire (Fig. 23). Supra-anal plate densely punctured, coarser than abdominal tergites; hind margin with 5 subacute and symmetrically slender teeth, which are deflexed and widely spaced, the largest one situated in the middle; teeth with margin smooth or small acute spines between the teeth, sometimes teeth fused together; lateral angles larger than the medial tooth. Cercus without setae dorsally, ventral surface convex with dense hairs (Fig. 24). Anterior margin of subgenital plate concave, anterolateral corners rounded; lateral margins concave (Fig. 25).
Etymology. The specific epithet is derived from the Latin word "quinquedentatus", referring to the posterior margin of supra-anal plate with 5 distinct and slender teeth.
Vertex exposed and without punctures. Face punctulated, ocelli round and with border distinct. Anterior margin of pronotum with a V-shaped excision mesially, a small recurved tubercle on the each side of the indentation; anterior 1/3 half of pronotum depressed, the floor densely granular; lateral and posterior half punctured, with a pair of small tubercles in the middle (Fig. 29). Tegmina and wings mutilated, probably well developed (Fig.5). Radial vein of tegmen with a long apical posterior branch mesially, which is branched at apex and with an accessory branch; the median vein branched before the midline (Fig. 82). Hind wing with subcostal vein branched at apical part; radial vein bifurcated at apex and forked medially; median vein simple; cubitus with 6 complete and 5 incomplete branches (Fig. 91). Anterior ventral margin of front femur without spines, hind margin with a large distal spine. Abdominal tergites punctured, the punctures denser and larger laterally; T7 with coarse surface scattered with sparse setae, and with circular depressions laterally, lateral margin crenulate, caudal angles oblique and tapering (Fig. 30). T6-T7 with small holes on the anterolateral corners, which is associated with minute sparse hairs in the openings. Abdominal sternites densely punctured; hind margin of S7 slightly convex and subgenital plate weakly exposed (Fig. 31). Supra-anal plate extremely coarse, hirsute and covered with depressions similar to T7 in density; hind margin with 7-8 relatively separated teeth, which have an uneven border with lateral ones larger than teeth in the middle, or two fused together; lateral angles equal or larger than the biggest tooth between them. Cercus basiconic, with ventral side swollen and with setae ventrally and dorsally (Fig.  32). Anterior margin of subgenital plate slightly concave or more or less straight, lateral margin curved inwards (Fig. 33).
Male genitalia. Genital phallomere L1 reduced to a small plate (Fig. 34); L2d tapering and bifurcated apically, major branch with apex rounded and a little larger than the lateral one (Fig. 35); R2 developed and curved, hook-shaped, with apex obtuse and slightly swollen (Fig. 36).
Female. Anterior margin of pronotum with smaller tubercles than male and the tubercles not recurved.
Etymology. The scientific epithet of this species is derived from the Latin word "anisodontus" which refers to the different teeth in the hind margin of the supra-anal plate. Description. Male. Body dark reddish brown, darker on caudal segments, or totally black (Fig. 7). Eyes black-brown and ocelli yellowish. Antennae, upper lip, mandible, labial palpi and maxillary palpomeres brown. Legs dark reddish brown, paler on coxae and trochanter. Abdominal sternites reddish brown with the middle of the first and second sternites brown (Fig.8).

Salganea taiwanensis
Vertex with few punctations, exposed; face densely punctulated; ocelli round and distinct. Anterior margin of pronotum thickened, with a small mesial V-shaped indentation, a small reflexed protuberance on the each side of the excision; anterior half of pronotum depressed, with sparsely granular surface; posterior half punctured, with 2 oblique mounds armed with 2 tubercles at apex (Fig. 37). Tegmina and wings well developed, extending beyond the abdominal terminal (Fig. 7). In tegmen, the radius with 3 short or 1 relatively long posterior branches; median vein simple or branched (Figs 83-84). Radius in hind wing with apical posterior branch near the middle, which is associated with 2 branches and one of them sometimes branched, some veins fused partially; median vein branched or not; cubitus with 5-6 complete  (Figs 37-40), 0.5 mm (Figs 41-45). and 6-8 incomplete branches (Figs 92-93). Anterior ventral margin of front femur with 0-4 spines and a small distal spine, hind margin with a large distal spine. Abdominal tergites punctured, and the punctures denser laterally; T4-T7 with holes on the anterolateral corners which are surrounded with fine hairs, the holes on T4 small or absent; lateral margins of T7 feebly crenulate, sometimes the irregularities subobsolete and indistinct, caudal angle oblique (Fig. 38). Abdominal sternites densely punctured, hind margin with a mesial concavity (Fig. 39). Supra-anal plate densely punctate, hind margin with 8-13 subequal teeth (10 in most cases), which are broad basally, triangular, or fused together, lateral angles obtuse and about the same size as the largest tooth between them. Cercus conical, very few or no setae dorsally, ventral surface swollen, densely setose (Fig. 41). Anterior margin of subgenital plate slightly concave, lateral margins sunken (Fig. 42).
Female. Essentially similar to male, but larger than male and with hind margin of the seventh sternite rounded (Fig. 40).

Description. Male. Body dark reddish, with the coloration similar to S. taiwanensis.
Vertex sparsely punctate, exposed; face densely punctulated; ocelli round and distinct. Anterior margin of pronotum weakly thickened, with a small mesial emargination, a protuberance on the each side of the excision; anterior half of pronotum depressed, the surface sparsely granular; posterior half punctured, with 2 tubercles (Fig.  9). Tegmina and wings mutilated, probably fully developed (Fig. 9). Anterior ventral margin of front femur with 2 spines and a small distal spine, hind margin with a large distal spine. T4-T7 with holes on the anterolateral corners which are surrounded by fine hairs, the holes on T4 are very small; lateral margins of T7 Panesthia-like (Fig.  46). Supra-anal plate densely punctate, hind margin with 10 subequal teeth, obtuse rounded (Fig. 47). The last abdominal sternite and subgenital plate were broken.
Measurements. Male, 3 th -5 th maxillary segments: 0.73/0.76/1.05mm; pronotum: length × width: 5.1 × 9.5mm; distance between disc tubercles: 2.2mm; body length: 27.4mm; fore leg: coxae: 2.42mm, trochanter: Remarks. Although the lateral margin of T7 is Panesthia-like, the characters of the holes in anterolateral corners of T4-T7 associated with setae, and the ridge along with the lateral margin of S7 are more typical of the genus Salganea. Thus, we place this species in genus Salganea. It is very similar to S. taiwanensis, only differing in the rounded teeth in the hind margin of supra-anal plate. To be rigorous, the relationship between this two species requires more specimens to provide an absolute determination.
Distribution. China (Guangxi). Description. Male. Body reddish brown, darker caudally (Fig. 11). Eyes blackish brown; ocelli yellowish. Antennae, upper lip, mandible, labial palpi and maxillary palpomeres reddish brown and only a little paler than body. Legs reddish brown, paler on coxae and trochanter. Abdominal sternites reddish brown with the middle of the former two sternites brown (Fig. 12). Face sparsely punctate and vertex exposed. Anterior margin of pronotum slightly concave mesially, with a small tubercle on each side of the excision; anterior half slightly depressed, the floor with sparse pustules; few punctations on posterior half, with a pair of small tubercles (Fig. 50). Tegmina and wings extending beyond the end of abdomen, sometimes mutilated (Fig. 11). Radial vein of tegmen with 1 forked posterior branch at base, or with 2 simple posterior branches; median vein branched before the midline (Figs 85-86). Radial vein of hind wing simple and branched apically, or with 3 small branches which terminate in the anterior apical angle; median vein branched; cubitus with 5 complete branches, which may be forked or not, and 7-8 incomplete branches (Figs 94-95). Anteroventral margin of front femur armed with 1 spine or unarmed, with or without a minute distal spine, hind margin with a distal spine. Abdominal tergites 1-6 sparsely punctate; T7 denser punctulated caudally, lateral margin weakly crenulate, laterocaudal angle slightly produced (Fig. 52); anterolateral corners with small holes in T6 and T7, some minute and indistinct in T5. Abdominal sternites punctulate, the last sternite densely punctuated and hind margin indented (Fig. 53). Supra-anal plate densely punctate, hind margin varied with 9-13 triangular teeth, border of teeth smooth or crenulate . Cercus conical, with few setae near the border dorsally and ventral surface setose (Fig. 55). Anterior margin of subgenital plate slightly concave, lateral margins slightly curved (Fig. 57).
Female. Differs from male as follows: anterior margin of pronotum smooth or indented mesially and the tubercles absent or weakly indicated (Fig. 51); hind margin of S7 entire (Fig. 54).
Face punctulated and vertex exposed. Ocelli small and round. Anterior margin of pronotum with a V-shaped emargination in the midline, a small recurved tubercle behind the margin on each side of the excision; anterior half depressed, the floor densely granular, lateral area punctate; region behind grooves convex and densely punctate, with one or two pairs of relatively large tubercles on the mounds symmetrically (Fig.  61). Tegmina and wings well developed, sometimes mutilated and remaining an uneven base (Fig. 15). Radius of tegmen with or without 1 long posterior branch which is forked; median vein branched (Figs 87-88). Radial vein of hind wing with one or more branches near the apex, some branches reforked, the posterior branch branched or not; median vein with two branches or simple; cubitus with 7-8 complete and 8-10 incomplete branches (Figs 96-97). Anterior ventral margin of fore femur equipped with 1-3 spines, and with or without a minute distal spine, posterior margin with a large distal spine. Abdominal tergites punctated, the punctures denser laterally and dorsoposteriorly, anterolateral corners usually without holes, rarely with small holes on T6 and T7 only; lateral angle of T6 produced into a rounded and oblique spine; lateral margin of T7 with 5-6 obtuse teeth, laterocaudal angle stout and subacute (Fig. 62). Abdominal sternites densely punctured, S7 with a depression on the caudal margin (Fig. 63), subgenital plate more or less exposed. Supra-anal plate densely covered with  (Figs 61-64), 0.5 mm (Figs 65-68).
Female. Differs only slightly from male in partial specimens as follows: anterior margin of pronotum slightly excised, and the tubercles indistinct behind the indentation.
Nymph. Similar to adult, but body yellowish-brown, anterior margin of the pronotum without excision and protuberance, the tubercles on the floor absent; depression of anterior half densely punctuate; meso-and metanotum with produced laterocaudal angle, the protrusion dark or black (Figs 17-18).
Distribution  (Fig. 19). Head black, dark reddish brown between eyes, ocelli and eyes with yellowish border. Antennae, upper lip, mandible, labial palpi and maxillary palpomeres dark brown. Legs black, coxae, trochanter and the former half of femora yellowish brown. Abdominal sternites black with the middle of the former five segments reddish brown, cercus reddish brown (Fig. 20).
Vertex exposed, punctured; face densely punctured; ocelli circular and distinct. Pronotum convex (anterior margin damaged, it is probably a developmental error), anterior and lateral area depressed, densely granular and equally distributed; posterior half with a distinct tubercle on each side of the midline, the floor densely punctured (Fig. 69). Tegmina and wings mutilated, but probably fully developed (Fig.  19). Anterior ventral margin of front femur with 2 spines, and a minute distal spine, posterior margin with a spine. Centre region of abdominal tergites sparsely punctured, more and larger laterally, and with dense setae; lateral angle of T6 produced; T7 hirsute, with large disc pits densely; round holes only present in the anterolateral corners of T6 and T7; lateral margin of T7 with 3 subacute and distinct teeth, sometimes also with subobsolete papulas, caudal angle produced into a strong and oblique spine (Fig. 70). Abdominal sternites densely punctured; S7 densely covered with hairs, hind margin emarginated (Fig. 71), subgenital plate slightly exposed. Supraanal plate convex, hirsute, with large disc pits densely; middle of hind margin with 8 unequal teeth, deflexed, which are triangular or apically truncate; caudal angles tapering, and same length as the largest tooth between them. Cerci conical, dorsal and ventral surfaces densely setose (Fig. 72). Anterior margin of subgenital plate depressed, anterolateral corners subacute, lateral margins straight and not concave (Fig. 73).
Etymology. The specific epithet "flexibilis" is derived from Latin, which means that the teeth on the hind margin of the supra-anal plate are deflexed.

Discussion
The members of Salganea are known to be burrowers in rotten logs (Figs 78-79), with a hard, rigid, pitted exoskeletion and a thick, scoop-shaped pronotum (Bell et al. 2007). Some macropterous ones shed their wings and only keep the basal region of tegmina and wings intact (Roth 1979;Maekawa et al. 1999b;Bell et al. 2007), i.e., S. quinquedentata sp. n., S. flexibilis sp. n. and S. anisodonta sp. n. as described in this paper, which are all collected by chopping logs and not by light trapping in tropical forests (Fig. 77). Most of them have shed their tegmina and wings and only one specimen of S. quinquedentata sp. n. kept these intact; the reason of shedding is maybe the combination of scraping them against gallery walls and the chewing action of conspecifics (Maekawa et al. 2008). The nymphs of S. quinquedentata sp. n. are not active and slowly crawl on the scraps of wood; but if frightened by sound and light, they will flee and hide below the scraps (Wang X.D., pers. obser.). Owing to this unique behavior of shedding their tegmina and wings, venation as an important taxonomic character has not been used widely in the classification of Panesthiinae. But a large number of species of Panesthiinae have fully developed tegmina and wings (Roth 1979). Moreover, Rehn (1951) considered that wings of this taxon had a characteristic venation which differed from other families. But after strict examination we find that the veins of the tegmina and wings are unstable. First, we find the venation of the left and right tegmina and wings of one specimen are variable. As in S. quinquedentata sp. n., the apical posterior radial vein is branched in the left tegmen (Fig. 80), but has 2 complete and 1 incomplete branches in the right one (Fig. 81); the cubitus has variable branches. The radial vein of the wing bifurcated near the apex, and the median vein is unbranched in the left wing (Fig. 89), but in the right one, the radius is not bifurcated apically, and the median vein branched at the apex ( Fig. 90). Second, the intraspecific venation is also variable, as in S. taiwanensis (92)(93)(98)(99)(100)(101)(102)(103)(104)(105)(106)(107)(108)(109)(110)(111)(112)(113); venations of all left tegmina illustrated here are significantly different, mainly in the numbers of each vein (98)(99)(100)(101)(102)(103)(104)(105)(106)(107)(108)(109)(110)(111)(112)(113). But the total number of veins at the margin appears relatively stable, as in S. taiwanensis, the CV total of tegmina is 11.19 (Table 1) and CV total of hindwings is 11.11 (Table 2), which are almost same as in the archaic species. The CV of the total number of veins in all living species were under 5.00 (Vršanský 2000). There are mainly 4 kinds of deformities of veins presented in the drawings (S. taiwanensis of 16 specimens, Figs 98-113), which are expressed as mutual fusion of veins 104,(107)(108)(109)(110)(111)(112)(113), lost of a branch (Cu,(109)(110)112), fusion of vein to another vein (102)(103)(104)(105)(106)(107)(108)110,111,113), or as veins with unfinished growth (Fig. 98) in both right and left tegmina. In hindwings, there are deformities expressed as fusion of radial veins (Figs 100-101, 109-110). Mass insects deformities expressed as fusion of wing veins most probably represent heritable mutations (Vršanský 2005). At the same time he mentioned that enhanced environmental stress might have caused the occurrence of mass mutations. Vršanský (2000) also made the conclusion that the variability of the venation of Blattaria species decrease from the archaic to more recent group. So we speculate that the deformities of S. taiwanensis listed above might be the result of adaptation to the environment, that is, their ancestors may be able fliers but now they have no chance to fly or lack ability of flight before entering the log. However, interspecific venation is relatively stable especially in hindwings (Figs 89-97). The subcosta is simple and long; the radial vein does not have more than five branches; the median vein is with one or without a branch on the anterior part. Overall, we find venation to be of little value as a specific character; but the venation variation is more stable and distinct at higher taxonomic levels. Additional investigation will be required to search for more stable wing characteristics to support our view.