The cockroaches of Balta Tepper from China, with the description of four new species (Blattodea, Ectobiidae, Pseudophyllodromiinae)

Abstract Four new species of cockroach genus Balta Tepper, 1893 are described and illustrated: B. crena sp. n., B. maculata sp. n., B. tangi sp. n., and B. yaoi sp. n. Balta picea (Bey-Bienko, 1958) is now regarded as a new synonym of Balta hwangorum (Bey-Bienko, 1958), which is redescribed and illustrated. Two new combinations are proposed: B. nodigera (Bey-Bienko, 1958), comb. n. and B. valida (Bey-Bienko, 1958), comb. n., and both species are redescribed and illustrated. A key to all species from China is provided.


Introduction
Balta Tepper, 1893 is a large genus comprising 98 species, 40 of which are distributed in Australia, and 14 in Mainland China and Taiwan. The others are distributed in Pacific islands, Africa, and India. Bey-Bienko (1958) described three species of Lupparia Walker, 1868 and two species of Balta from China. Roth (1991) thought that Balta and Lupparia are quite similar. The genera Balta and Lupparia are distinguished by the size of the apical triangle of the hind wing (Balta spp. with smaller apical triangle). Che et al. (2010) briefly reviewed the research history of the genus; they also mentioned the relationship between Balta and Lupparia and some difficulty existing in discriminating these two genera. From then on, no one reported new species of the genus Lupparia. Recently, many cockroach specimens were received from Prof. Shuqiang Li (IOZCAS, Institute of Zoology, The Chinese Academy of Sciences), which were collected by means of canopy spraying conducted mainly in Yunnan and Hainan Provinces from 2009 to 2012. Material was also received from Prof. Shunxiang Ren and Zaifu Xu (SCAU, South China Agricultural University) that was collected from Guangdong Province.
After examining the specimens and comparing them with the original descriptions of Bey-Bienko (1958) and Asahina (1965), descriptions of four new species are appropriate, and are included here. Additionally, Balta picea (Bey-Bienko, 1958) is placed as a junior synonym of Balta hwangorum (Bey-Bienko, 1958), and two new combinations are proposed.

Materials and methods
The terminology mainly follows Roth (2003). The terms for wing-veins are according to Li and Wang (2015). Morphological terms referring to spines are as follows: spines on the antero-ventral margin of the front femur with one or more proximal stout spines succeeded by a row of spinules of uniform length, terminating in two (B 2 ) or three (B 3 ) large spines (Type B); while the proximal stout spines absent (Type C) (Roth 2003). 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 taken using a Canon 50D plus a Canon EF 100mm f/2.8L IS USM Macro lens with the aid of Helicon Focus software. Material examined, including types of new species, is deposited in the Institute of Entomology, Southwest University (IESWU) in Beibei, Chongqing, China.
Male genitalia. Supra-anal plate with posterior margin distinctly produced and concave in U-shape in the middle, right and left paraprocts simple (Fig. 22). Subgenital plate with hind margin strongly concave medially; two lateral lobes with styli on either apex direct dorsally and with fine spines (Figs 23,24). Hook-like phallomere on right side and with preapical concavity (Fig. 27). Median phallomere with base acuminate, apex blunt with some long setae, median phallomere appendage with some fine spines ( Fig. 26). Left phallomere complex, consisted of several irregular sclerites (Fig. 27).
Female. Both tegmina and hind wings slightly beyond the end of abdomen. Subgenital plate with hind margin rounded.
Etymology. Latin word crena means "nick", referring to subgenital plate with its hind margin strongly concave medially.
Distribution. China (Yunnan). Differential diagnosis. This species resembles Balta yaoi sp. n. in appearance, but can be distinguished from the latter by the following characters: 1) tegmen with more obvious black spots, cells slightly more hyaline and without yellowish brown spots (Fig. 31); while in the latter species, the tegmen has fewer and less obvious black spots, cell with yellowish brown spots; 2) median phallomere complex, the appendage base with brush-like structure (Fig. 38); while the latter with median phallomere simple, the appendage arched and without brush-like structure.
Description. Male. Body tawny. Face between eyes brown, between ocelli and antenna sockets with a light brown stripe, under antennal sockets also with a light brown stripe (Fig. 28). Pronotum with some small scattered and symmetrical spots or inconspicuous stripes, with tawny disk, lateral borders hyaline (Fig. 30). Tegmen and hind wing tawny, tegmen with black spots (most distributed on veins) (Fig. 31). The middle of anterior margin of abdominal tergites blackish brown. Third and fourth maxillary palpomeres approximately same length, both distinctly longer than the fifth (Fig. 29). Tegmen with M and CuA oblique (Fig. 31). CuA of hind wing with three complete branches and without incomplete ones (Fig. 32). Front femur of type C 2 (Fig. 33), tarsal claws strongly asymmetrical and unspecialized (Fig. 34). Abdominal tergites unspecialized.
Female. Supra-anal plate longer than subgenital plate, hind margin of the former with triangular process in the middle. Subgenital plate simple with hind margin rounded.
Etymology. Latin word maculata meaning "with dots", referring to the tegmina with dots.
Distribution. China (Yunnan). Differential diagnosis. Balta tangi species resembles B. spinea in appearance, but can be distinguished from the latter by the following characters: 1) face with transversal stripes between interocular space (Fig. 40) while face of B. spinea without transversal stripes but having two longitudinal stripes, each of them with one small rounded white spot; 2) subgenital plate in ventral view between the styli slightly emarginated and with a protrusion in the middle (Fig. 48) but in B. spinea without the protrusion.
Description. Male. Body yellowish brown. Vertex brownish yellow. Face with three stripes (Fig. 40). Disk of pronotum yellowish brown and with some small scat- tered and symmetrical blackish brown spots, lateral borders of pronotum hyaline (Fig.  42). Lateral border of abdomen sterna with round blackish brown spots (Fig. 6). Third and fourth maxillary palpomeres nearly the same length, distinctly longer than the fifth (Fig. 41). Hind wing with triangle apical, near apex of R with posterior branches, CuA with three complete branches (Fig. 44). Front femur type C 3 (Fig. 45), tarsal claws strongly asymmetrical and unspecialized (Fig. 46). Abdominal tergites unspecialized.
Male genitalia. Supra-anal plate symmetrical with hind margin slightly concave in the middle, paraprocts simple (Fig. 47). Subgenital plate with hind margin slightly emarginated and with process in the middle, conical styli located on the apex of either lateral lobes respectively, ventral side of subgenital plate with some fine spines near the stylus (Fig. 48). Hook-like phallomere on right side and with preapical concavity (Fig. 49). Median phallomere sticklike, base thick and strong, apex gradually becomes sharp-pointed, near the middle part of median phallomere with an arc-shaped appendage, base, and apex with short setae (Fig. 50). Left phallomere complex, apex with spinous structure (Fig. 51).
Female. Sexual dimorphism, female body thicker and stronger than male, both tegmina and hind wings degraded, just extending to supra-anal plate, RA with one or two branches.
Etymology. This species is named in honor of Mr. Guo Tang, who collected the holotype of the species.
Distribution. China (Yunnan). Differential diagnosis. This species is similar to B. valida comb. n. in appearance, but can be distinguished in the following characteristics: 1) For the former, median phallomere appendage without brush-like structure (Fig. 62), while in the latter with brush-like structure; 2) subgenital plate with hind margin curved concave (Fig. 60), while in the latter not concaved medially.
Description male. Body yellowish brown (Figs 7, 8). Vertex slightly yellow, between eyes with a slightly brown stripe, under the stripe with a slightly brown triangular spot, under antennal sockets with or without a stripe (Fig. 52). Disk of pronotum yellowish brown, with some small scattered and symmetrical blackish brown spots, two lateral border hyaline (Fig. 54). Tegmen yellowish brown, with a few small round black spots, cell with yellowish brown spots. The lateral border of abdomen with round blackish brown spots. Third and fourth maxillary palpomeres nearly same length, longer than the fifth (Fig. 53). Tegmen with M and CuA oblique (Fig. 55). Hind wing with M simple, without branches, CuA with three complete branches and without incomplete ones, hind wing with small apical triangle (Fig. 56). Front femur Type C 2 (Fig. 57), tarsal claws strongly asymmetrical and unspecialized (Fig. 58). Abdominal tergites unspecialized.
Female. Both tegmina and hind wings slightly beyond the end of abdomen. The end of abdomen rounded.
Etymology. This species is named in honor of Mr. Zhiyuan Yao, who collected the holotype of the species.
Distribution. China (Yunnan).  Redescription. Male. Body yellowish brown (Figs 9, 10). Vertex to anterior margin of antennal sockets reddish brown, face yellowish brown to blackish brown (Figs 9,10). Pronotum with inconspicuous black brindle or two oblique and symmetrical stripes, with disk reddish brown to black brown, two lateral borders, anterior and posterior margin yellowish brown and hyaline (Fig. 66). Legs yellowish brown to blackish brown. Abdomen blackish brown. Apex of subgenital plate with reddish brown spots or without. Fourth and fifth maxillary palpomeres approximately same length, both distinctly shorter than the third (Fig. 65). Tegmen with M and CuA slightly oblique (Fig. 67). Hind wing with M without branches, CuA with five complete branches and without incomplete ones (Fig. 68). Front femur type C 2 (Fig. 69), tarsal claws strongly asymmetrical and unspecialized (Fig. 70). Abdominal tergites unspecialized.

Balta hwangorum
Male genitalia. Supra-anal plate in ventral view short, hind margin arched, slightly emarginated in the middle; right and left paraprocts similar (Fig. 71). Subgenital plate symmetrical throughout except at the base, hind margin with deep V-shape emargination, styli similar, conical, arising on lateral lobes (Fig. 72). Hook-like phallomere on right side, hook slender (Fig. 73). Median phallomere sticklike, slightly curved, apex acuminate, near the apex part with a sclerite, base of arc appendage with brush-like structure (Fig. 74). Left phallomere complex, apex with a bifurcate spinous structure and a slender hairs structure (Fig. 75).
Female. Slight sexual dimorphism in that the female body is smaller than the male. Supra-anal plate symmetrical, rounded, hind margin divided in the middle. Subgenital plate broad and rounded.
Remarks. Several specimens were separated as two species by Bey-Bienko, mainly based on the body color (1958). However, after examining a large number of specimens, the results show that body color of B. hwangorum varies. Moreover, in Bey-Bienko's records, in B. hwangorum, the length of lobes of the subgenital plate is different among the species, but in fact we find no difference.
Male genitalia. Supra-anal plate posterior margin slightly convex in the middle, paraprocts simple (Fig. 83). Subgenital plate in ventral view with hind margins strong-ly emarginated in the middle, conical styli located on the distal of lateral lobes, ventral side of subgenital plate with some fine spines (Fig. 84). Hook-like phallomere on right side, the hook structure short and thick (Fig. 85). Median phallomere sticklike, thick and strong at base, apex with two different size spines; one associated median phallomere appendage stronger and with setae at apex, (Fig. 86). Left phallomere with left side apex spine-like (Fig. 87).
Distribution. China (Fujian, Yunnan). (Bey-Bienko, 1958) (Figs 13,14). Vertex between eyes brick-red, between two ocelli yellow, remainder of face yellowish brown and without stripes (Figs 13,14). Maxillary palpomeres yellowish brown with either base blackish brown. Base of antenna yellowish brown and the rest blackish brown to black. Pronotum yellowish brown and disc with some black spots, lateral borders hyaline. Legs yellowish brown. Base and two borders of abdominal sternites black (Fig. 14). Third and fourth maxillary palpomeres approximately same length, both distinctly longer than the fifth (Fig. 89). Tegmen with M degeneration and CuA with more branches (Fig. 91). Hind wing with M without branches, near apex of R with short branches, CuA with four to six complete branches and two or three branches of them bifurcated near apex (Fig. 92). Front femur type B 3 (Fig. 93), tarsal claws strongly asymmetrical and unspecialized (Fig. 94). Abdominal tergites unspecialized.

Balta valida
Male genitalia. Supra-anal plate in ventral view short, hind margin finely rounded, right and left paraprocts unsymmetrical (Fig. 95). The hind margin of subgenital plate concave near lateral sides and with densely setae; styli conical, with densely scattered short setae, located on lateral lobes (Fig. 96). Hook-like phallomere on right side and with preapical concavity (Fig. 97). Median phallomere thick and strong and near apex with a brush-like structure; base of appendage also with long strip brush-like structure (Fig. 98). Left phallomere complex, with brush-like structure (Fig. 99).