﻿The genus Japonitata Strand (Insecta, Coleoptera, Chrysomelidae, Galerucinae) in Taiwan: a redefinition of the genus and descriptions of two new species

﻿Abstract The genus Japonitata is redefined based on comparison with its allied genera Paraplotes Laboissière, 1933 and Shairella Chûjô, 1962. Japonitataquadricostata Kimoto, 1996 and J.caerulea Kimoto, 1996 are transferred to Shairella. Japonitatahoujayisp. nov. and J.jungchanisp. nov. are described. Biological information is provided for J.houjayisp. nov. In addition, the generic boundary of Shairella is redefined by including S.quadricostata and S.caerulea.


Introduction
described a new genus, Japonia Weise, 1922, based on the species Phyllobrotica nigrita Jacoby, 1886. However, Japonia a junior homonym of a snail genus (Gould 1859). A replacement name, Japonitata, was proposed by Strand (1935). This genus is composed more than 30 species in the Oriental and Palaearctic regions (Nie et al. 2017). Most species (90%) were described after 1980 and 60% were described from China (Kimoto 1970(Kimoto , 1996(Kimoto , 2004Jiang 1981, 1986;Jiang 1989;Yang 1992;Yang et al. 1997;Sprecher-Uebersax 1998, 1999;Yang and Li 1998;Medvedev 2012). Although most species were described during the past 50 years, none or few morphological characters were illustrated or included in species descriptions. In Taiwan, only two species were described by Kimoto (1996), with no additional information provided since then. The Taiwan Chrysomelid Research Team (TCRT) was founded in 2005 and is composed of ten members. All of them are amateurs interested in producing a complete inventory of chrysomelid species in Taiwan. Members of TCRT have collected sufficient material of the two Taiwanese species of Japonitata to allow their biology to be explored. These two species are different not only in color forms (red vs. black) and behavior (diurnal vs. nocturnal), but also in morphology. Nocturnal species shows great similarity to species of Shairella Chûjô, 1962. Two more species are now available for study with help from citizen scientists and loans from museums. In addition, Japonitata Strand is similar to Paraplotes Laboissière and some species of both genera have been confused. For example, J. clavata Yang & Wu, 1998 is a junior synonym of P. clavicornis Gressitt & Kimoto, 1963 and P. rugatipennis (Chen & Jiang, 1986) was transferred from Japonitata by Zhang et al. (2008); J. indica (Takizawa & Basu, 1987) was transferred from Paraplotes by Medvedev (2002). Diagnostic characters proposed by Zhang et al. (2008) for both genera are evaluated here. In this study, besides describing new species and redescribing known species, the taxonomic status of these is evaluated by redefining the genus Japonitata and its allied genera, Paraplotes and Shairella.

Materials and methods
For taxonomic study, the abdomens of adults were separated from the forebodies and boiled in 10% KOH solution, followed by washing in distilled water to prepare genitalia for illustrations. The genitalia were then dissected from the abdomens, mounted on slides in glycerin, and studied and drawn using a Leica M165 stereomicroscope. For detailed examinations a Nikon ECLIPSE 50i microscope was used.
At least three pairs from each species were examined to delimit variability of diagnostic characters. For species collected from more than one locality, at least one pair from each locality was examined. Length was measured from the anterior margin of the eye to the elytral apex, and width at the greatest width of the elytra.

Taxonomy
Japonitata Strand, 1935Japonia Weise, 1922: 70 (Type species: Phyllobrotica nigrita Jacoby, 1885). Japonitata Strand, 1935: 294 (replacement name for Japonia Weise, 1922nec Gould, 1859. Diagnosis. Japonitata can be separated from Paraplotes by the presence of posteriorly open anterior coxal cavities (closed in Paraplotes); pronotum longer, 1.5-1.7 × wider than long (pronotum short, 2.4-2.9 × wider than long in Paraplotes), basal border immarginate (basal border margined in Paraplotes); disc with lateral depressions (disc with transverse depressions in Paraplotes); disc of elytra with reduced punctures (disc of elytra with fine or coarse punctures in Paraplotes), with one more longitudinal ridge in addition to lateral ridge. Other characters proposed by Zhang et al. (2008) are not diagnostic. Antennae are variable among Paraplotes species. For example, ratios of length to width from antennomeres I-XI of males of P. taiwana Chûjô, 1963: 3.2: 1.6: 2.4: 2.8: 2.8: 2.1: 2.3: 2.2: 2.9: 3.1: 4.6; antennomeres VI-VIII much shorter than those of J. jungchani sp. nov., but much narrower in those of P. cheni Lee, 2015 (sympatric with P. taiwana), ratios of length to width from antennomeres I-XI of males 3.3: 1.6: 3.1: 3.3: 3.5: 3.1: 3.4: 3.7: 3.6: 3.9: 5.0. These characters are not diagnostic for either genus. The rugose or pubescent disc of the elytra occurs in some species of Paraplotes. Thus, it is not diagnostic. Appendiculate tarsal claws occur in both genera, with no difference between them. Some genitalic characters are diagnostic. Aedeagi of adults of Japonitata have a well sclerotized, elongate tectum (variable tectum with one pair of apico-lateral sclerites in Paraplotes), lacking endophallic spicula (with one long median spiculum, and one or two additional pairs of lateral spicula in Paraplotes); spermathecal receptaculum as wide as pump (spermathecal receptaculum swollen, wider than pump in Paraplotes). Japonitata species are also similar to those of Shairella with the lateral borders of pronotum marginate but apical and basal borders unmargined. However, Japonitata differs from Shairella by the posteriorly open anterior coxal cavities (closed in Shairella); robust antennae, antennomeres IV-X less than 3.5 × longer than wide (antenna slender, antennomeres IV-X more than 3.5 × longer than wide in Shairella), with distinct lateral ridges and an additional longitudinal, distinct ridge on each elytron (with weak lateral ridge and no additional distinct ridge on each elytron in Shairella). Aedeagi of adults of Japonitata have a well sclerotized, elongate tectum (membranous tectum in Shairella); lack endophallic spicula (with one slender median speculum in Shairella); spermathecal receptaculum short, wider than pump (spermathecal receptaculum long, as wide as pump in Shairella). Diagnostic characters of Japonitata, Paraplotes, and Shairella can be summarized as follows (Table 1).
Remarks. Japonitata quadricostata Kimoto, 1996 andJ. caerulea Kimoto, 1996 are transferred to Shairella since both species fit the redefinition of the genus. They are characterized by normal elytra. Shortened elytra and reduced hindwings occur in all other species of Shairella; however, reduced hindwings also occur in some populations of S. quadricostata.
Diagnosis. Adults of J. houjayi sp. nov. are similar to those of J. ruficollis Jiang, 1989 from China (Xizang) with reddish brown bodies, but differ in possessing black antennae and dark brown legs (yellow antenna with one or two apical antennomeres black, and reddish brown legs in J. ruficollis).
Host Etymology. The new species name is dedicated to Mr. Hou-Jay Chen (陳厚潔), the first team member to find the habitat and collect type specimens.
Diagnosis. This new species is similar to J. bipartita Chen & Jiang, 1986 from China (Shaanxi and Fujian) with reddish brown body and black head and prothorax. It differs in having black antenna with the three apical antennomeres reddish brown, and dark brown fore and middle legs.
Host plant and biology. Unknown, but one adult was collected by sweeping flowers. Etymology. The new species name is dedicated to Mr. Jung-Chan Chen (陳榮章), the first person to collect type specimens.
Distribution. South Taiwan including Pingtung and Taitung counties.
Variations. Some distinct variation occurs in female genitalic characters among different populations. Pumps of spermathecae are larger in those of Wulai (烏來) (Fig. 6I); much slender and lacking apical process in those of Erhwanping (二萬坪) (Fig. 6J). Apices of ventrite VIII are wider and setae not reduced medially in those of Wulai (烏來). Hindwings are normal in northern and central Taiwan and low-elevations of southern Taiwan (Fig. 7A), but they are reduced in different degrees between different populations of mid-elevations of southern Taiwan. Degree of reduction of hind wings is similar between individuals of both sexes of the same populations. Those in Tengchih (藤枝) are less reduced, ~ 57% with normal hind wings (Fig. 7B). Those in Hsito (溪頭) are reduced moderately, ~ 50% with normal hind wings (Fig. 7D). Those in Peitawushan (北大武山) have the same length of hind wings as those in Hsito but wider (Fig. 7E). Those in Erhwanping (二萬坪) are reduced strongly, ~ 40% with normal hind wings (Fig. 7C).
Diagnosis. Adults of Shairella quadricostata (Kimoto, 1996), comb. nov. and S. caerulea (Kimoto, 1996), comb. nov. are characterized by normal elytra and functional hindwings (shortened elytra and reduced hindwings in other Shairella; Lee and Beenen 2017) although individuals in some populations of S. quadricostata have more or less reduced hindwings. Shairella quadricostata is distinguished from S. caerulea by possessing black elytra with three pairs of weak longitudinal ridges (Fig. 5A-F) (bluish black elytra without longitudinal ridges besides lateral ridge in S. caerulea; Fig. 9); median internal ridge of abdominal ventrite V in males expanded from apex, abbreviated before base (Fig. 6K) (median internal ridge of abdominal ventrite in males expanded from apex to base in S. caerulea; Fig. 10G); apically narrowed apex of aedeagus (Fig. 6C) (bifurcate apex of aedeagus in S. caerulea; Fig. 10C); apex of spermatheca rounded with or without small process (Fig. 6H-J) (apex of spermatheca swollen, bifurcate in frontal view in S. caerulea; Fig. 10H, I).
Host plant. Hemiboea bicornuta (Hayata) Ohwi (Gesneriaceae).  Biology. Adults of Shairella quadricostata were observed active at night and feeding on leaves of Hemiboea bicornuta. However, adults were hard to find with the exception of a single event. Three adults were collected on 11 May 2022 in Tengchih (藤枝) (Fig. 5G). We collected 39 adults on 9 July 2014 in Erhwanping (二萬坪). Many host plants were growing on a steep slope and numerous adults were feeding on leaves (Fig. 5H).
Distribution. The flighted populations are widespread in low-elevations of Taiwan and mid-elevations of northern and central Taiwan, and flightless populations are restricted to mid-elevations of southern Taiwan (Fig. 8).

Diagnosis. Shairella caerulea
Host plant and biology. Unknown.
Distribution. This species is probably widespread in Taiwan although few specimens are available for study.

Discussion
The former studies have confused the taxonomic boundaries between Japonitata and Paraplotes (Chen and Jiang 1986;Medvedev 2002;Zhang et al. 2008). This confusion is probably due to overlooking detailed structures of the aedeagus and female genitalic characters. Shapes and structures of the tectum and endophallic sclerites of the aedeagus, and spermatheca in S. quadricostata and S. caerulea indicate great similarity among both species and species of Shairella. Diagnostic characters between Japonitata, Paraplotes, and Shairella are reevaluated and proposed in this study. Transfer of S. quadricostata and S. caerulea to Shairella is supported based on these diagnostic characters. This study also emphasizes the importance of detailed studies and illustrations of male and female genitalic characters.
Presence or absence of hindwings and elytral calli, or shortened elytra are not key characters for generic diagnoses. For example, females of Taiwanese species of Paraplotes have reduced hindwings and shortened elytra (Lee 2015). Taiwanese species of Sikkimia (Lee and Bezděk 2016) and some species of Lochmaea (Lee 2019) have reduced elytral calli and hindwings. The brachelytrous Shairella is redefined here by including S. quadricostata and S. caerulea with normal elytra. This implies that a number of additional Japonitata species should be transferred to Shairealla. Specifically, species of Japonitata without one pair of distinct ridges on the elytra should be evaluated as possible members of Shairella.
Adults of Shairella quadricostata (Kimoto), comb. nov. are widespread and some populations have reduced hindwings in mid-elevations of southern Taiwan. They are allopatric with other members of the genus except at Erhwanping (二萬坪) and Hsitou (溪頭), where S. aeneipennis Chûjô, 1962 also occurs (Fig. 8). However, they are separated ecologically since both species utilize different food plants (Hemiboea bicornuta for S. quadricostata and Clinopodium laxiflorum var. taiwanianum for S. aeneipennis). Interestingly, adults and larvae of S. chungi Lee & Beenen, 2017 in southern Taiwan also feed on leaves of Hemiboea bicornuta. This species is allopatric with S. quadricostata, although the flightless populations are more northern in distribution and the winged populations are southern. A previous hypothesis for brachelytry in leaf beetles of tropical forest habitats is different from Lee's proposal for Paraplotes (Lee 2015): "Reduction of hind wings may result from the production of physogastric females. Nocturnal behavior increases survival since natural enemies are less of a threat. Males actively search for mates by night. In harsh environments such as islands, deserts and alpine regions, flight is not essential to survival and energy can be diverted to egg production (Beenen and Jolivet 2008). Thus, brachelytry is a predictable evolutionary trend.". The species (S. quadricostata) with long antennae and darker color is adapted to nocturnal activity since natural enemies are less of a threat. Some populations have reduced hindwings as an adaptation to stable microhabitats (mid-altitudes in southern Taiwan). Elytra are reduced further due to allopatric speciation (S. chungi Lee & Beenen, 2017). Host plant shifts cause adaptive radiation in these circumstance (S. aeneipennis, S. guoi Lee & Beenen, 2017, S. motienensis Lee & Beenen, 2017, and S. tsoui Lee & Beenen, 2017.