﻿Two new species of the genus Smaragdina Chevrolat, 1836 (Coleoptera, Chrysomelidae, Cryptocephalinae) from China

﻿Abstract Two new species of the genus Smaragdina Chevrolat from China are reported: S.hejingensis Duan, Wang & Zhou sp. nov. from Xinjiang, and S.magnipunctata Duan, Wang and Zhou sp. nov. from Yunnan. Six species, S.divisa (Jacoby), S.insulana Medvedev, S.kimotoi Lopatin, S.laboissierei (Pic), S.laosensis Kimoto & Gressitt, and S.oculata Medvedev are new country records for China. Color illustrations and line drawings of general habitus and morphological details are given. All types of two new species are deposited in the collection of Institute of Zoology, Chinese Academy of Sciences (IZ-CAS).


Introduction
The genus Smaragdina Chevrolat, 1836 has 350 recognized species (Warchałowski 2012;Wang and Zhou 2013), making it the most species-rich genus of the tribe Clytrini. The genus is distributed in the Palearctic, Oriental, and Afrotropical regions, with 64 species found in China (Clavareau 1913;Gressitt and Kimoto 1961;Tan et al. 1980;Kimoto and Gressitt 1981;Tan 1988;Lopatin 2004;Medvedev 2010;Regalin and Medvedev 2010;Warchałowski 2010Warchałowski , 2012Wang and Zhou 2013). This genus is similar to Aetheomorpha Lacordaire, 1848 but can be distinguished by the slight epipleural lobe of elytra and the pygidium covered by the elytra (Warchałowski 2012). This distinction must be carefully used and examined, otherwise misidentification may occur for the beginner when facing some intermediate forms.
The Chinese species of Smaragdina have been studied by many specialists (e.g., Gressitt and Kimoto 1961;Tan et al. 1980;Kimoto and Gressitt 1981;Lopatin and Konstantinov 2009;Regalin and Medvedev 2010), but most of these studies were comprehensive and included all or most of the family Chrysomelidae, and Smaragdina was treated as only a part in those broader studies. Some recent studies on Smaragdina have included excellent keys to the species from the Oriental and Palearctic regions and, thus, are very important in identifying the Chinese species (Medvedev 2010;Warchałowski 2010). The most recent study on Smaragdina was by Wang and Zhou (2013), which is part of the series of publications concentrated on the Chinese leaf beetle fauna (Wang and Zhou 2011, 2012, 2013, 2020Su and Zhou 2017;Duan and Zhou 2021;Duan et al. 2021aDuan et al. , 2021b. There were few studies strictly concentrated on the biology of Smaragdina, i.e. life cycles, development, host plants, etc. Gao et al. (2019) studied the life cycle of Smaragdina nigrifrons (Hope, 1843) as vineyard pest, but this species is now moved out of the genus Smaragdina. Erber (1968Erber ( , 1969Erber ( , 1988 comprehensively reviewed Clytrinae and other related subfamilies, Agrain et al. (2015) reviewed the ant-nest related leaf beetles, and Chaboo et al. (2016) catalogued all known immature stages of camptosomate leaf beetles. Tan et al. (1980) provided some valuable records for host plants.
This paper, as a continuation of our leaf beetle studies (see above), describes two new species from China and reports six species as new country records for China. We increase the number of the Chinese species of Smaragdina to 72. We provide color illustrations and line drawings of general habitus and other structures for each species included. All types of the new species are deposited in the collection of Institute of Zoology, Chinese Academy of Sciences (IZ-CAS).

Dissection of specimens
Dried specimens were relaxed in hot distilled water at 80 °C for about 2 h to soften the body and ease dissection. The abdomen was separated with insect pins from the rest of the body and soaked in 10% KOH solution, and then in a hot water bath for 15 min to advance the process. After this procedure, the specimens were transferred to distilled water to rinse the residual KOH solution off and stop the bleaching process. The aedeagus, spermatheca, and rectal sclerites were dissected out from abdomen and placed in glycerin on a microslide.

Photography and drawings
The dissected parts were placed into glycerin for observation and measured with an apochromatic stereomicroscope Zeiss SteREO V12. Color photographs of the adults and genitalia were captured with an Axio Zoom V16 fluorescence stereo zoom microscope and photomontage was performed in Zen 2012 (blue edition) imaging software. Adobe Photoshop CS6 was used in digital post-processing of the color images, and Adobe Illustrator 2020 was used to make the line drawings.

Morphological terminology and measurement
The term "rectal sclerites" (ventral rectal sclerites, dorsal rectal sclerites) is used throughout the paper according to Schöller et al. 2008, and "fossa" is used throughout the paper to indicate the round and deep structure on the last abdominal segment in female; it is widely used term in many publications in Cryptocephalinae (Gressitt and Kimoto 1961;Tan et al. 1980;Kimoto and Gressitt 1981;Tan 1988). Body length was measured to cover the whole length from the apex of pronotum to the apex of elytra in dorsal view.

Specimens studied
Specimens used in this study are from the Institute of Zoology, Chinese Academy of Sciences, Beijing, China (IZ-CAS).
Measurements are average values calculated from the values of at least 10 specimens, or all if fewer specimens were available. The following abbreviations were used to identify the institutions of holotype deposition.

Taxonomy
Diagnosis. Body shape elongate and subcylindrical, usually smaller than 6 mm. Head small, very short; mandibles short; eyes round or elongate; antennae slender, 2 nd and 3 rd antennomeres short and equal, following antennomeres serrate. Pronotum transverse, posterior angles rounded; scutellum large. Elytra without distinct epipleural lobes. Legs short, fore legs sometimes slightly longer than others; tarsi of females usually long and narrow, 1 st tarsomere longer than 2 nd ; legs of males usually stouter than female's, tarsi broader and shorter. Pygidium not exposed. Measurements (n = 6). Body length males: 5.2-5.9 mm, females: 5.1-5.6 mm. Description. Body (Figs 1A, B, 2A) oblong, largely metallic blue. Mandibles yellowish brown, apex tinged with brown; labrum darkish brown; ventral side of mouthpart yellowish brown; four basal antennomeres yellow, others brown. Pronotum largely metallic blue, lateral sides with yellowish brown marking. Scutellum black. Ventral side of body largely metallic blue, prosternum yellowish brown, femora of hind legs tinged with black, last segments of tarsi and claws brown.
Pronotum transverse, about 2× as wide as long, moderately convex; anterior margin slightly convex, lateral margins rounded, posterior margin sinuated, all margins (especially lateral ones) bordered; surface with coarse punctures, denser on median basal area. Scutellum widely triangular, with extremely fine punctures; apex slightly elevated over elytral surface. Elytra 1.7 times as long as wide at humeri, covered with confused and dense punctures, interstices shorter than a puncture diameter, punctures becoming sparse posteriorly, and nearly disappearing at elytral apices.
Female. Coloration of body darker than male, base of hind tibiae black; legs slender, tarsi narrow. Last segment of abdomen with a fossa. Spermatheca (Figs 1C, 2H) hook-shaped, apex swollen and blunt, duct base thickened, not coiled. Rectal sclerites moderately sclerotized, ventral rectal sclerites (Fig. 1H) large, clubbed; dorsal rectal sclerites (Fig. 1I)  Diagnosis. This new species is well distinguished from all its congeners by the presence of unique black markings on the elytra and strong punctures arranged in regular rows with their interspaces impunctate. Etymology. The specific epithet is from the Latin words "magni-" and "punctata" in reference to the big punctures of the elytra. Measurements (n = 4). Body length males: 3.7 mm, females: 3.9-4.3 mm. Description. Body (Figs 3A, B, 4A) oblong, largely khaki. Head yellowish brown, Mandibles with black apex; two basal antennomeres yellow, others brown; sometimes vertex black. Pronotum yellowish brown. Scutellum black. Elytra khaki, margins black, disc with two black round markings. Ventral side of body largely yellowish brown, ventral side of mesothorax and metathorax black; legs yellowish, tibiae outer side and tarsi somewhat brown.
Distribution. China (Yunnan). Remark. This species is recognized by having the apical half of the elytra distinctly paler than the basal half, and the apex of aedeagus narrowly truncate. It has not previously been recorded from the territory of China. Remark. This species is recognized by the fulvous body color, pale flavous spots on the elytra, and the sharp apex of the aedeagus. Originally found in Vietnam, we can confirm this species occurs in China.     Measurements (n = 10). Body length males: 4.4-4.9 mm, females: 4.9-5.9 mm.

Smaragdina insulana Medvedev, 1992, new country record for China
Distribution. China (Hainan); Vietnam. Remark. The fulvous dorsal body and the aedeagus with a broad and parallel-sided apical process, distinguish this species from S. divisa. Originally from Vietnam, we confirm that S. kimotoi occurs in China. Smaragdina laboissierei (Pic, 1928), new country record for China Figures 11,12 Smaragdina laboissierei Pic, 1928: 34 (orig  Remark. The Chinese specimens were identified as this species by the yellowish-brown pronotum with a black stripe and the apical process of aedeagus triangular, which is acute and strongly curved downwards. This species was previously only known from Vietnam.  (Pic, 1928) A habitus B maxilla C labium D dorsal view of aedeagus E lateral view of aedeagus F ventral view of aedeagus G spermatheca. Scale bars: 0.5 mm. Figures 13, 14 Smaragdina laosensis Kimoto & Gressitt, 1981: 320 ( Distribution. China (Yunnan); Laos. Remark. Following the description of Kimoto and Gressitt (1981, especially figs 21b, 23a), we determined the Chinese specimens as S. laosensis. This species was originally recorded in Laos.  Measurements (n = 4). Body length males: 4.8-5.0 mm, females: 5.5 mm. Distribution. China (Yunnan); India. Remark. According to the aedeagus with triangular apex and specific pubescence, the Chinese specimens are certainly S. oculata (Medvedev 2010: fig. 82), which has only been recorded from India.

Discussion
This study contributes new faunistic discoveries and increases the number of Chinese species of Smaragdina from 64 to 72. This is a very important advance in the taxonomy of this large genus in the tribe Clytrini. The Chinese Smaragdina have not been studied in last 30 years or longer (Gressitt and Kimoto 1961;Tan et al. 1980;Kimoto and Gressitt 1981;Tan 1988), except for one study originating from our laboratory (Wang and Zhou 2013). This is our second contribution, and it is of considerable value, as it adds to the data published by Medvedev (1988a: a systematic revision of Indo-China Smaragdina; 2010: a key to oriental species).
In the early studies on the leaf beetles, including Smaragdina, species were reported by older conventions without specimen dissections; thus, few morphological details of aedeagus, spermatheca, rectal sclerites, etc. were provided (Gressitt and Kimoto 1961;Tan et al. 1980;Kimoto and Gressitt 1981). All our papers on leaf beetles, including this and the previous on the Chinese Smaragdina, include morphological dissections and provide the detailed color figures of the new and other species ( Wang and Zhou 2011, 2012, 2013, 2020Su and Zhou 2017;Duan and Zhou 2021;Duan et al. 2021aDuan et al. , 2021b. This improvement in methodology dramatically decreases mistakes in species identifications and robustly grounds our discoveries. This, together with our other studies on leaf beetles, are of great significance in filling gaps in the Chinese faunistic composition and promoting the taxonomic progress in the subfamily Cryptocephalinae.