New and little known Latindiinae (Blattodea, Corydiidae) from China, with discussion of the Asian genera and species

Abstract A new Latindiinae, Brachylatindia xuigen. et sp. nov., is described and illustrated from Tibet, China. The new genus Beybienkonusgen. nov. is established to include Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov. The Asian Latindiinae is discussed with a total of six genera included. A checklist of Asian species and a key to the Asian genera of Latindiinae are provided.

Three Asian genera were historically included in Latindiinae (Princis 1963), but were later excluded, i.e., Homopteroidea, Ctenoneura, and Ipolatta. Members of Ctenoneura are unique among cockroaches for their absence of the genital hook, and differ from Latindiinae by the asymmetrical subgenital plate, single stylus, more complex venation, and the apterous female ). However, Homopteroidea and Ipolatta were excluded from Latindiinae without providing any reason; recent papers now indicate that the Asian Latindiinae are more diverse than previously thought: Qiu et al. (2016) reported the genus Sinolatindia from China and Lucañas (2018) described genus Gapudipentax from the Philippines.
Since Latindiinae species are small and unnoticeable, specimens are difficult to obtain. Recently, we obtained some living individuals and specimens from Yunnan and Tibet, China. All materials were collected from the rotten wood. We thus take this opportunity to carefully study them and report upon this little known subfamily from China. The status of Homopteroidea and Ipolatta are reconsidered, and a checklist of the Latindiinae species from Asia as well as a key to the Asian genera are provided.
The definition of Latindiinae here follows that of Qiu et al. (2016) and . Morphological terminology used in this paper mainly follows Roth (2003), genitalia terms follow Klass (1997), and venation terms follow Li et al. (2018).
The genital segments of the examined specimens were dipped in 10% NaOH and observed in glycerine jelly using a Motic K400 stereomicroscope and a Leica M205A stereomicroscope. Venation drawings were made with the aid of Adobe Photoshop CS6, a Leica M205A stereomicroscope and a Motic K400 stereomicroscope. Photo-graphs of the habitus and characters were made using a Leica M205A stereomicroscope. All photographs were modified in Adobe Photoshop CS6.
For pairing and comparison, we selected seven samples representing different morphologies and genders from different locations to sequence their COI genes. The COI sequences are deposited in the National Center for Biotechnology Information GenBank (accession numbers MN116495, MN116496, MN116497, MN116498, MN116499, MN116500, MN116501). The extraction procedure was according to the Hipure Tissue DAN Mini Kit. Total DNA was stored at -20 °C. Primers for the amplifications are COI-F3 (5'-CAACYAATCATAAAGANATTGGAAC-3') and COI-R3 (5'-TAAACTTCTGGRTGACCAAARAATCA-3'). The amplification conditions were as follows: initial denaturation at 98 °C for 2 min, followed by 35 cycles of 10s at 98 °C, 10s for 51 °C, and 15s for 72 °C, with final extension of 2 min at 72 °C. Laboratory reagents were provided by TsingKe Co, Ltd., China. All voucher specimens are deposited at SWU. The genetic divergence value was quantified based on the Kimura 2-parameter (K2P) distance model (Kimura 1980), using MEGA 7 (Tamura et al. 2013) with 1000 bootstrap replicates.
Diagnosis. Small, brachypterous, smooth but with sparse micro spines. Head oval, ocelli absent; pronotum roundly triangular, meso-and meta-notum somewhat reduced; front femur type C 2 , tarsal claws simple, arolia present; male with a gland at the centre of 4 th tergum; subgenital plate of female valved.
This new genus resembles Gapudipentax Lucañas, 2018, but it can be readily distinguished from the latter by the following characters: 1) head sub-oval, while head triangular in Gapudipentax; 2) pronotum triangular with rounded edges, smooth, with indistinct micro setae, while pronotum pentagonal with rounded edges, distinct pubescent in Gapudipentax; 3) male with subtriangular tegmen, while male with subquadrate tegmen in Gapudipentax; 4) front femur with two long apical spine at hind margin, while front femur without any long apical spines in Gapudipentax; 5) tarsal claw not serrated, while tarsal claw serrated in Gapudipentax; and 6) male with tergal gland, while male without tergal gland in Gapudipentax.
Generic description. Body small, smooth, sexual dimorphism indistinct, both brachypterous. Male: head longer than width, oval, vertex not exposed. Ocelli absent. Pronotum triangular with rounded edges, with indistinct and micro setae. Meso-and meta-notum reduced, narrowed, median of both slightly extended. Tegmina reduced, reaching only up to the middle of the 2 nd tergum; wing reduced, very small (flightless). Front femur type C 2 , apex without spine; mid-and hind femora each with a spine at apex and a spine at apical portion of hind margin. Tarsomere 1 longer than the rest of tarsomeres combined. Pulvulli absent. Tarsal claws simple, symmetrical. Arolia present. Abdomen with 4 th tergum specialised, with a gland medially. Supra-anal plate trapezoidal, with large hyaline area, apex concave; paraprocts hooked at apical portions; cerci each with a small spine at apex. Subgenital plate symmetrical; styli simple, similar. Genitalia complex, with long and robust genital hook (L3), R2 elongate.
Geographical distribution. China (Tibet). Etymology. Brachys (Greek for short) + latindia refers to a Latindiinae cockroach with brachypterous tegmina. Diagnosis. As for the genus (vide supra). Description. Male (holotype). General: measurements (mm): body length (vertex to abdomen tip): 6.2, pronotum length × width: 2.2 × 3.0, tegmen length: 2.1. Size small, brownish yellow, tegmina and wings reduced (Fig. 1A, B). Head: oval, with very sparse setae, brownish yellow. Vertex convex, sheltered under pronotum. Eyes small, wide apart; interocular space much greater than the distance between antennal sockets. Ocelli absent. Frons smooth, two very shallow spots situated between the lower parts of the antennal sockets. Antennal sockets small, each with a row of setae at upper margin. Antennae dark brown, long, 7.4 mm, longer than the body length. Clypeus small, nearly trapezoidal, ante-clypeus and post-clypeus not indicated. Labrum small, sub-triangular, apex blunt. Maxillary palpi moderate (Fig. 2B). Pronotum: brownish yellow, lateral parts sub-transparent. Smooth, surface without pubescence, but very sparse micro setae (cannot be observed by naked eyes, but visible under microscope). Shape subtriangular, widest near the hind angles, apex rounded, hind angles rounded ( Fig. 2A). Mesonotum and metanotum. Both somewhat reduced; mesonotum semi-oval, apical margin thickened; apical margin of metanotum protruded, almost reaching to half of the 1 st tergum, the protruded part quadrated and thickened (Fig. 2E). Tegmina and wings: both reduced, flightless. Tegmen smooth, almost reaching the edge of the 2 nd tergum, lobate, apex rounded; venation reduced, main veins simple. Wing small, triangular, venation indistinct (Figs 1A, 2F). Legs: smooth, setose, whitish yellow, tibiae and tarsi brownish yellow. Front femur with a row of small spines at hind margin, ending with a long spine and a short spine near apex (type C 2 ) (Fig. 2C). In middle and hind femur, each femur with a row of sparse spines at hind margin, ending with one long spine; one long spine appearing at the apex of anterior margin. Tibiae normally with some long spines and short setae. Tarsi covered with many spines; the length of tarsus 1 longer than the total length of  tarsi 2 to 5; tarsal claws normal, symmetrical, small; arolia minute ( Fig. 2D). Abdomen: smooth, brownish, 4 th tergum specialised, with a gland medially, hind margin of 4 th tergum thinned and slightly concave in the middle (Fig. 2G). Supra-anal plate with a large transparent area medially, apex widely concave, margin setose; paraprocts with long setae; cerci long, lateral portions setose, apex with a spine (Figs 3A-B). Subgenital plate setose; styli cylindrical ( Fig. 3C). Genitalia: complex. Left phallomere: L1 large, consists of two irregular sclerites, the ventral one with a stick-like process on the left, apex round; L2 small, elongate and curved, median with a lamina; L3 very robust, apical portion enlarged, then thinner and curved toward apex, apex sharp; L4N with pda and paa well developed, long and sharp; L4M thin, transparent. Right phallomere: R1M and R3 small; R2 with two distinct elongate sclerites, the ventral one short, stick-like, apex enlarged and rounded, the dorsal one extremely long, lying across the whole phallomere (Fig. 3D, E).
Natural history. This species was collected from the rotten wood from the forest of Guxiang, Bomi (H. Xu et J.-Y. Qiu, pers. comm.) (Fig. 11B).
Remarks. This species is similar to the male of Brachylatindia xui sp. nov., but its front femur has a right-angle protrusion near the base (Fig. 5C), mesonotum is trapezoidal, metanotum is not reduced (Fig. 5E), tegmina are larger, and the wings are absent. These differences may be sexually dimorphic, so to further verify they are different species, we sequenced the COI genes of B. xui sp. nov. and this female specimen (GenBank access numbers MN116501 and MN116499, respectively, for the male and nymph specimens of B. xui sp. nov., MN116496 for this female specimen). The results show that the divergence between the two species is 15.7% (0% between the holotype and paratype of B. xui sp. nov.). This result indicates that this specimen is not the female of Brachylatindia xui sp. nov.
Diagnosis. This new genus is unique by having two robust spines on each hind femur and one curved robust spine at the apex of each hind tibia in male. The hind legs of male are robust. Apex of each cercus with a long spine in both sexes. Both brachypterous and macropterous types are present in this genus.
Generic description. Body large for Latindiinae, smooth; both brachypterous and macropterous types are present.
Brachypterous male. Head longer than width, oval, vertex slightly exposed. Ocelli represented as two white spots. Pronotum semi-oval, smooth. Meso-and meta-notum slightly reduced, median not extended. Tegmina reduced, reaching up to half of abdomen; wing reduced, small and elongate (flightless). Front femur type C 1 ; mid-and hind femora each with a spine at apex and two spines at apical portion of hind margin, the two spines of hind femur well developed, robust. Hind tibia with a robust long spine and a thin long spine at apex. Tarsomere 1 longer than the rest of tarsomeres combined. Pulvulli absent. Tarsal claws simple, symmetrical; arolia absent. Abdomen without tergal modification. Supra-anal plate narrowly triangular, with large hyaline area medially, apex with two rounded lobes; paraprocts simple; cerci smooth dorsad, setose ventrad, each with a long spine at apex. Subgenital plate symmetrical; styli simple, similar. Genitalia with small genital hook (L3), right phallomere large.
Macropterous male. Unknown. Brachypterous female. Similar to brachypterous male. Tegmina more reduced, not exceeding the half of abdomen, wing much more reduced, very small (flightless). Hind legs not as robust as male, spines normal, not enlarged. Supra-anal plate subtriangular, apex emarginated, margin setose, ventral surface setose. Subgenital plate valved, medial slit entire through the apex to the base.  Description. Brachypterous male. General: measurements (mm): body length (vertex to abdomen tip): 10.1-10.6, pronotum length (midline) × width (the widest points): 3.1-3.2 × 4.6-4.8, tegmen length: 4.9-5.1, tegmen width: 2.7-2.8. Size small, body smooth, brownish yellow ( Fig. 6 A, B). Head: longer than width. Vertex slightly exposed under pronotum, convex, darker than the remaining part of head. Eyes small, wide apart; interocular space much greater than the distance between ocelli and antennal sockets. Ocelli represented as two white spots, situated above antennal sockets. Frons smooth, two brown spots situated between the lower parts of the antennal sockets. Antennal sockets small. Antennae dark brown, shorter than the body length (8.6-10.3 mm). Face smooth, large. Clypeus small, nearly trapezoidal, the edge between ante-clypeus and post-clypeus indistinct. Labrum small, sub-triangular. Maxillary palpi long (Fig. 8A). Pronotum: light brownish yellow, lateral parts sub-transparent. Smooth, surface without pubescence, but very sparsely with micro setae (can't be observed by naked eyes, even easily overlooked under microscope). Shape semi-oval, widest at 1/4 from the base, hind angles round (Fig. 8B). Tegmina and wings: both reduced, flightless. Tegmen smooth, brown, reaches to the 4 th or 5 th tergum, nearly rectangular, apical portion slightly protruding, overall outline slightly rounded; venation simple. Wing small, elongate, curved, reaching the apex of 2 nd or 3 rd tergum (Figs 6A, 9C, D). Legs: smooth, brownish yellow, sparsely covered with short setae, hind legs robust. Front femur with a row of small spines at hind margin, ending with a long spine at apex (type C 1 ) (Fig. 8F), while in middle and hind femur without row of spines at hind margin; in middle and hind legs, each femur with a long spine at anterior apex and two long spines at hind apex; in hind femur, the two spines at hind apex extremely robust and long. Tibia with a spinous protrusion at apex (small in front and middle tibiae, extremely long in hind tibia); surface of tibia normally with some long spines, the spines at tibial apex longer than the spines at tibial surface; in hind tibia, two of the apical spines extremely long (one is thin and straight, the other is robust and curved) (Fig. 8D). Tarsi covered with many spines; the length of tarsus 1 sub-equal to the total length of tarsus 2 to 5; tarsal claws normal, symmetrical, moderate in size; arolia absent ( Fig. 8G). Abdomen: smooth, brownish, terga without modification, lateral margins with small spinous pubescence. Supra-anal plate (Fig. 10A) pubescent, narrowly triangular, apex with two rounded lobes; paraprocts simple; cerci long, smooth and without pubescence dorsally, with pubescent ventrally, apex with a very long and sharp spine (Fig. 8H, I). Subgenital plate simple, sparsely pubescent, base with rough setae laterally; styli slender (Fig. 10B). Genitalia: Left phallomere: L1 consists of two irregular sclerites, the dorsal one slice-like, the ventral one with three unequal-sized protrusions; L2 thick, straight; L3 small, curved, S-shaped; L4N simple, straight; L4M small, slicelike. Right phallomere: large. R3 and R1M elongate; R2 with two sclerites, the ventral one stout, irregularly rounded, the dorsal one extremely long, irregular, lays across the whole phallomere (Figs 10C-D).
Natural history. Individuals were captured from rotten wood, or under the barks of the rotten wood (Fig. 11C, D). Under the lab condition, individuals can feed on bread crumbs and apple pieces; one can prevent the others from grabbing its food by kicking (by the strong hind legs), or fast running away with food (food were carried by front legs). Females were noticed producing oothecae in April (Fig. 12C), the nymphs were very fast hatched around 10-15 days.
Remarks. Bey-Bienko (1957) described Ctenoneura acuticerca based on two females from Yunnan, China. From the original description, C. acuticerca is characterised by the smooth pronotum, absence of intercalary vein and arolia, triangular supra-anal plate with emarginate, valvular subgenital plate, and cerci with a large spine apically. Bey-Bienko (1957) himself had indicated C. acuticerca is related to Ctenoneura aberrans Hanitsch, 1928. However, C. aberrans had been moved to genus Homopteroidea since this species is quite different from Ctenoneura (Roth 1995a). Later, Qiu et al. (2017) doubted C. acuticerca Bey-Bienko, 1957 to be a Ctenoneura species according to the absent intercalary vein and arolia, and the female Ctenoneura was found to be apterous. However, due to no specimens of Ctenoneura acuticerca being available, the problem remained unsolved.
Recently we obtained abundant living individuals of Ctenoneura acuticerca from Yingjiang, Yunnan. These roaches were captured from the same locality in the rotten woods. We noticed that this species displays polymorphism. Most individuals are  brachypterous, while individuals were very rarely macropterous in the material we examined (Fig. 12B). We compared the brachypterous and macropterous individuals both by morphological features and the COI sequences (one brachypterous male, one brachypterous female and one macropterous female were sequenced, GenBank access numbers MN116497, MN116498 and MN116500, respectively). Both results showed that the brachypterous and the macropterous individuals are conspecific: 1) morphologically, the brachypterous individuals and the macropterous individuals show no differences but in the shape of pronotum and the length of tegmina and wings; and 2) the divergence of COI sequences between the brachypterous male and the macropterous female is 0%, and the divergence between the brachypterous female and the macropterous female is 0.2%. Thus, we confirmed the brachypterous and the macropterous individuals are the same species. Meanwhile, we also sequenced one of the Tibetan specimens by COI (GenBank access number MN116495), and found the divergence between the Tibetan specimen and the Yunnan specimen is only 4.3%-4.4%. Thus, we can confirm that the Tibet individuals are conspecific with the Yunnan individuals.
After a carefully study of Ctenoneura acuticerca, we readily confirmed that this species should be excluded from the genus Ctenoneura by the winged female, the complex male genitalia with genital hook, and the simplified venation without intercalary vein; and it does not belong to any of the other genera in Corydiidae. We herein establish genus Beybienkonus gen. nov. to accommodate C. acuticerca. Thus, Beybienkonus acuticercus (Bey-Bienko, 1957), comb. nov. is proposed.

Discussion
In Asia, Latindiinae genera were poorly recorded. Princis (1963) listed only three genera (Homopteroidea, Ipolatta, Ctenoneura) in Latindiidae (now Latindiinae). Only Ctenoneura was recently studied and proved to be different from Latindiinae , while the other two should be kept as members of Latindiinae.
Homopteroidea Shelford currently contains eight species, all of which are restricted to Southeast Asia (Fig. 13). We examined the Homopteroidea collection of OUM and consulted former papers (Hanitsch 1929;Roth 1995a;Roth 1995b;Qiu et al. 2016). Homopteroidea is proved to belong to Latindiinae by the small and wide apart eyes, simplified venation, the dense fringe-like spinules on the hind margin of front femur, abdomen), and shortened wings. Its supra-anal plate is transverse, and subgenital plate is described as "profunde fissa (= deeply split)". The head shape of Ipolatta resembles that of Latindia, Sinolatindia and Gapudipentax; the character in the subgenital plate indicates that the holotype is a female and is identical to the characters of female Latindiinae. Thus we consider Ipolatta as a Latindiinae genus. Nevertheless, this genus is only known from the original description, and its real identity needs further confirmation. Qiu et al. (2017) also mentioned that Ctenoneura gigantea Roth, 1993 was "aberrant" in Ctenoneura. This species was described based on one none-abdomen individual from Perak, Malaysia (Roth 1993). The wing venation exhibited in Roth (1993) is in general the Latindiinae type, so we would determine this species to be a Latindiinae. Lacking specimens to study, it may be a new genus, but for now its status remains unsolved.