Taxonomy of the Cryptocephalus heraldicus Group (Coleoptera: Chrysomelidae, Cryptocephalinae) from China

: This is a study on the leaf beetle subgenus Cryptocephalus Geoffroy, 1762 from China, with the particular emphasis upon the species-group classiﬁcation of the subgenus and the taxonomy of the Cryptocephalus heraldicus species group. A new key is compiled to all the species groups found in China. Four new species are described from China: Cryptocephalus ( Cryptocephalus ) biordopunctatus sp. nov. from Yunnan, C. hani sp. nov. from Shanxi, Hubei, Shaanxi and Gansu, C. incisodentatus sp. nov. from Sichuan and Yunnan, and C. nigroﬂavusiventerus sp. nov. from Yunnan. Three species are found for the ﬁrst time in China: C. lacosus Pic, 1922, C. nigriceps Allard, 1891 and C. rajah Jacoby, 1908. The species C. nigrolimbatus Jacoby, 1890 is transferred from the subgenus Burlinius Lopatin to this subgenus and assigned to the Cryptocephalus heraldicus group. The species number of this group is now 30 in total according to our result of taxonomic review. A key to all the mainland China species of this species group is provided as well as high quality color images and line drawings of adult habitus, aedeagus, and other important structures. All the types of the new species are deposited in the collection of Institute of Zoology, Chinese Academy of Sciences (IZ-CAS).


Introduction
The genus Cryptocephalus Geoffroy, 1762 (Coleoptera, Chrysomelidae, Cryptocephalinae, Cryptocephalini) is a megadiverse leaf beetle taxon which has a wide geographical distribution and is recorded in almost all zoogeographical regions of the world [1][2][3][4]. However, it has not been revised taxonomically in the past few decades [3]. Indeed, it is very difficult to revise the whole genus, a total of ca. 1800 species known up to now. There were many excellent works published with their attentions concentrated on regional faunas [2,[4][5][6][7][8]. Even more works were listed in Schöller (2002) [3]. This paper is a continuous of our previous studies on this genus and its related groups from China. Schöller (2002) gave a brief review of the classification of the genus Cryptocephalus Geoffroy; it listed a catalogue of ten subgenera in total and five of them were recorded to occur in China, namely, Anteriscus Weise, 1906, Asionus Lopatin, 1988, Burlinius Lopatin, 1965, Cryptocephalus nominative and Heterichnus Warchałowski, 1991 [3]. In this study, we focused on the subgenus Cryptocephalus which includes also Cerodens Burlini, 1969, a subgenus valid then in Schöller (2002) but now as a synonym of Cryptocephalus nominative by Sassi (2014) [3,9].
The genus Cryptocephalus Geoffroy, 1762 is an early established taxon and all its subgenera were erected much later, mostly for the fauna of the Palaearctic Region [3]. Even though the genus was subdivided into different subgenera and many species were separated out of the subgenus Cryptocephalus, it is still a very large taxon even merely to the Chinese fauna. It was shown to be an effective approach to divide the species of this genus or subgenus into different species groups; this approach was used by many entomologists. For example, White (1969) studied the genus Cryptocephalus in America north of Mexico, including 71 species and 33 subspecies, and categorized them in 12 species groups according to the regular puncture rows on elytra and the coloration on pronotum and elytra [8]; Warchałowski (2010) revised the fauna of the Palaearctic Region and subdivided all the species into 11 species groups according to the body dorsal hairs, the elytral puncture rows, and the coloration of pronotum, elytra and legs [4].
For the genus Cryptocephalus,  revised 84 species (and subspecies) mainly occurred in China and divided them into three species groups: C. regalis group with obvious pubescence on the dorsal side (recently being treated almost all to the subgenus Asionus), C. stchukini group without pubescence but with irregular puncture rows on the elytra, and C. trifasciatus group without pubescence but with regular puncture rows on the elytra [5]. Gressitt and Kimoto (1961) revised 131 species from China and Korea and divided them also into three species groups [6]. Tan et al. (1980) followed Chen's species group classification [10].
In the present study, we tried to establish an easy-used species group classification and compiled a key to all the species groups of the subgenus Cryptocephalus from China. It may benefit the future study on the Chinese Cryptocephalus and the related taxa. We described also four new species which belong to the Cryptocephalus heraldicus group, namely, Cryptocephalus (s. str.) biordoipunctatus sp. nov. from Yunnan, C. (s. str.) hani sp. nov. from Shanxi, Hubei, Shaanxi, and Gansu, C. (s. str.) incisodentatus sp. nov. from Sichuan and Yunnan, and C. (s. str.) nigroflavusiventerus sp. nov. from Yunnan. Three species were found as new record to China: C. (s. str.) lacosus Pic, 1922 [11], C. (s. str.) nigriceps Allard, 1891 [12], and C. (s. str.) rajah Jacoby, 1908 [13]. Moreover, C. (s. str.) nigrolimbatus Jacoby, 1890 [14] was transferred from the subgenus Burlinius  to this one and assigned to this species group [14]. Finally, the total species number of the Cryptocephalus heraldicus group is thus 34 based on the present study and all the Chinese species are listed in the paper.

Materials and Methods
Dissection and photography: dried specimens were relaxed in hot water at 80°C for about 2 h, to soften the beetle body and ease dissection. The abdomen was separated with insect pins from the rest of the body, soaked in 10% KOH solution and heated in a water bath for 15 min to advance the process, and then transferred into distilled water to rinse the residual KOH solution off and stop the bleaching process. Afterwards, the aedeagus, spermatheca and rectal sclerites were prepared. The dissected parts were placed in glycerin for observation and measurement with an apochromatic stereomicroscope Zeiss SteREO V12. Color pictures 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 pictures, and Adobe Illustrator 2020 was used to make the line drawings.
Measurements are average values calculated from the values of at least five specimens, or all available specimens in case less than five specimens were available. The following abbreviations are used in the text to indicate the measurements of the specimens:  Burlini, 1954) [9,21,22].
Type species: Chrysomela sericea Linnaeus, 1758. As a megadiverse leaf beetle group from China, the subgenus Cryptocephalus includes now only those species which have not been separated out of this group and not been categorized to the other subgenera either, namely, Anteriscus Weise, 1906 [23], Asionus Lopatin, 1988 [24], Burlinius Lopatin, 1965 [25], and Heterichnus Warchałowski, 1991 [26]. The reason is that the genus Cryptocephalus Geoffroy, 1762 [15] was an early-established taxon and all its subgenera were erected much later [3]. With respect to so large a taxon of many species and difficulty in species identification, we tried here to establish an user friendly species group classification and compiled a key to all the species groups of the subgenus Cryptocephalus s. str. from China, based on a reevaluation of the characters which were used in species group classification by   [5], Gressitt and Kimoto (1961) [6], and Warchałowski (2010) [4].
This subgenus is closely related to the genus Melixanthus Suffrian, 1854 [27], but the antennae of the latter are shorter than half of the body and the terminal antennal segments are usually thickened. This subgenus is also similar to the subgenus Burlinius Lopatin, 1965 [25], but this taxon has a larger-sized body and the relatively larger head and eyes, with aedeagus not prolonged into two or three processes with all the species. The subgenus is also similar to the subgenus Asionus Lopatin, 1988 [24], but the latter with erect hairs on elytra (at least on posterior part) and their last tarsomere free with terminal 2/3. With respect to the subgenus Heterichnus Warchałowski, 1991 [26], they can be distinguished by the following characters: Heterichnus has the male fore legs prolonged and the tarsi more or less flattened and prolonged [4].
Head less than one-half as broad as prothorax, nearly round in frontal outline and smooth, very sparsely and indistinctly punctate, vertex with a longitudinally shallow groove. Eyes emarginated below middle, superior eye-lobes separated slightly wider than antennal insertions. Clypeus impunctate, anterior margin slightly concave. Antennae of male longer and thicker than female, reaching apical 1/4 of elytra; 1st segment thick, clubbed, 2nd spherical, 2/5 as long as 1st, 3rd slender, about 1.5 times as long as 2nd, 4th slender slightly longer than 3rd, shorter than 5th, 6th longer than 5th, from 6th segment on somewhat equal in length, 5th-8th broadened and flatted, and last segment pointed apically.

mm.
Description. Body ( Figure 1A-B) medium size, pale ochraceous. Head testaceous vertex with a narrow and weakly brown vertical stripe; apex of mandibles darkish brown antennae yellowish brown on first four segments, reddish brown on last seven. Pronotum slightly ochraeous, basal margin black. Scutellum lightly yellow, with darkish brown ba sal margin. Elytron yellowish brown, basal margin reddish brown. Ventral surface o body and legs yellowish brown, claws black.
Head less than one-half as broad as prothorax, nearly round in frontal outline and smooth, very sparsely and indistinctly punctate, vertex with a longitudinally shallow groove. Eyes emarginated below middle, superior eye-lobes separated slightly wider than antennal insertions. Clypeus impunctate, anterior margin slightly concave. Antennae o male longer and thicker than female, reaching apical 1/4 of elytra; 1st segment thick clubbed, 2nd spherical, 2/5 as long as 1st, 3rd slender, about 1.5 times as long as 2nd, 4th slender slightly longer than 3rd, shorter than 5th, 6th longer than 5th, from 6th segmen on somewhat equal in length, 5th-8th broadened and flatted, and last segment pointed apically.
Pronotum ( Figure 1A-B) convex, smooth, and shining, nearly 1/2 as long as broad trapezoidal from dorsal view; anterior margin straight in anterodorsal view; basal margin weakly sinuate, obtuse and truncate on middle; disc evenly convex, smooth, impunctate Scutellum heart-shaped, wider than length, narrowed and slightly rounded apically, slop ing upward apically, smooth and impunctate.    Elytron ( Figure 1A-B) slightly more than two times as long as broad, humeri somewhat prominent, glabrous, rounded-truncate apically. Disc of each with eleven somewhat oblique rows of fairly deep punctures, interval of puncture rows that differs alternately, interspaces with extremely fine punctures.
Ventral surfaces of body with rather closely fine punctures and shortly pale pubescence. Prosternum rectangular, surface uneven, central of anterior margin triangularly protruding, posterior margin with a pair of lobes. Mesosternum broad, width about 2.2 times of length, surface coarse, posterior surface slightly concave. The middle part of metasternum wrinkled. Pygidium with densely fine punctures and short pubescence.
Aedeagus ( Figures 1D-F and 2A-C) elongate, sword-shaped, about 3.9 times as long as wide. Apex of median lobe triangular, slightly narrower than middle, round at apex, moderately curved in lateral view; with several pubescence on each side of apex, impunctate. Median orifice with median sclerite bending inwards below surface. Inner sac rather slender, triangular. Tegmen Y-shaped, moderately sclerotized.
Distribution. China (Yunnan) (Figure 9). Differential Diagnosis. This new species is similar to C. (s. str.) gestroi Jacoby [32], but can be distinguished from the latter by the interval of puncture rows that differs alternately, by the pronotum narrower and by the aedeagus of males with pubescence on ventral part.
Etymology. The specific epithet is from the Latin words "bi, ordo," and "punctatus", to indicate the appearance of elytra.  Elytron ( Figure 1A,B) slightly more than two times as long as broad, humeri somewhat prominent, glabrous, rounded-truncate apically. Disc of each with eleven somewhat oblique rows of fairly deep punctures, interval of puncture rows that differs alternately, interspaces with extremely fine punctures.
Ventral surfaces of body with rather closely fine punctures and shortly pale pubescence. Prosternum rectangular, surface uneven, central of anterior margin triangularly protruding, posterior margin with a pair of lobes. Mesosternum broad, width about 2.2 times of length, surface coarse, posterior surface slightly concave. The middle part of metasternum wrinkled. Pygidium with densely fine punctures and short pubescence.
Aedeagus ( Figures 1D-F and 2A-C) elongate, sword-shaped, about 3.9 times as long as wide. Apex of median lobe triangular, slightly narrower than middle, round at apex, moderately curved in lateral view; with several pubescence on each side of apex, impunctate. Median orifice with median sclerite bending inwards below surface. Inner sac rather slender, triangular. Tegmen Y-shaped, moderately sclerotized.
Distribution. China (Yunnan) (Figure 9). Differential Diagnosis. This new species is similar to C. (s. str.) gestroi Jacoby [32], but can be distinguished from the latter by the interval of puncture rows that differs alternately, by the pronotum narrower and by the aedeagus of males with pubescence on ventral part.
Etymology. The specific epithet is from the Latin words "bi, ordo," and "punctatus", to indicate the appearance of elytra. Description. Body ( Figure 3A,B) ochraceous. Head ochraceous, vertex with a narrow reddish brown vertical stripe; labrum yellow; mandibles reddish brown, apex darkish brown; antennae yellowish brown on first four segments, darkish brown on last seven. Pronotum slightly pale yellowish testaceous, with black basal margin. Scutellum ochraceous, anterior and posterior margins black, lateral margins brown. Elytron ochraceous, with black basal margins. Ventral surface of body black, propleura and mesopleura yellowish brown; lateral side of abdomen, pygidium and legs yellowish brown, 1/3 basal part of tibia and tarsi black.
Head more than one-half as broad as prothorax, nearly round in frontal outline, surface uneven, wrinkled; vertex with a longitudinally groove; frons with silver pubescence. Eyes emarginated below middle, superior eye-lobes separated slightly narrower than antennal insertions. Clypeus impunctate, wrinkled, anterior margin slightly concave. Antennae of male long and thin, reaching apical 1/5 of elytra; 1st segment thick, clubbed, 2nd spherical, 1/3 as long as 1st, 3rd slender, about two times as long as 2nd, 4th slender, about equal with 1st, shorter than 5th, from 5th segment on somewhat equal in length, 5th-8th broadened and flatted, and last 3 segments long and thin.
Pronotum ( Figure 3A,B) convex, smooth, and shining, nearly 0.6 as long as broad, trapezoidal from dorsal view; anterior margin straight in anterodorsal view; lateral margin convex, 1/2 basal part can be seen in dorsal view; basal margin weakly sinuate, obtuse and truncate on middle; disc evenly convex, smooth, finely punctate. Scutellum trapezoidal, wider than length, basal margin truncate, sloping upward apically, smooth and impunctate.
Elytron ( Figure 3A,B) about 2.2 times as long as broad, humeri somewhat prominent, glabrous, and rounded-truncate apically. Disc of each with eleven somewhat oblique rows of fairly deep punctures, slightly confused at lateral region; interspaces without any punctures.
Ventral surfaces of body with rather dense punctures and shortly silver pubescence. Prosternum trapezoidal, longer than wide, surface uneven, central of anterior margin triangularly protruding, lateral ridges slightly elevated, posterior margin with a pair of lobes. Mesosternum broad and small, square. The middle part of metasternum glabrous, with sparsely coarse punctures. Pygidium with densely fine punctures and short pubescence. The first tarsi of front and middle legs distinctly broader and longer than hind legs.
Aedeagus (Figures 3C-E and 4A-C) elongate, about 3.8 times as long as wide. Apex of median lobe arcuate, slightly narrower than middle, round at apex, weakly curved in lateral view; with several pubescence on each side of apex, impunctate. Median orifice with median sclerite bending inwards below surface. Inner sac rather bilobed. Tegmen Y-shaped, moderately sclerotized.
Distribution. China (Shanxi, Hubei, Shaanxi, Gansu) ( Figure 9). Differential Diagnosis. This new species is similar to C. (s. str) licenti Chen [5], but can be distinguished from the latter by the elytra in an ochraceous coloration and with the basal margin black, while the latter with darkly reddish brown elytra and sutural margin black. The female of new species has thinner duct which coils under thirty times.   Distribution. China (Shanxi, Hubei, Shaanxi, Gansu) ( Figure 9). Differential Diagnosis. This new species is similar to C. (s. str) licenti Chen [5], but can be distinguished from the latter by the elytra in an ochraceous coloration and with the basal margin black, while the latter with darkly reddish brown elytra and sutural margin black. The female of new species has thinner duct which coils under thirty times.
Etymology. The specific epithet is named in memory of the holotype collector, Mr. Han Yinheng. Description. Body ( Figure 5A,B) small, ochraceous, testaceous on pronotum. Head ochraceous, vertex with a narrow reddish brown vertical stripe; antennal insertions and anterior margin of clypeus reddish brown; mandibles black. Basal margin of pronotum and margins of elytron black, and sutural, lateral, apical margins of elytron tinted with reddish brown. Scutellum black, disc with some darkish red. Ventral surface of body reddish brown, legs yellowish brown.
Head more than one-half as broad as prothorax, nearly round in frontal outline; smooth and shiny, very sparsely and finely punctate; vertex with a longitudinally narrow groove; frons with sparsely long pubescence. Eyes emarginated below middle, superior eye-lobes separated less wide than antennal insertions. Clypeus with sparse punctures, anterior margin slightly concave. Antennae of males longer and thicker than females, reaching apical region of elytra; 1st segment thick and long, clubbed, 2nd oblong, 2/5 as long as 1st, 3rd-5th slender, 3rd about 1.5 times as long as 2nd; 4th slightly longer than 3rd, shorter than 5th, 6th longer than 5th, from 6th segment on somewhat broad and equal in length.
Pronotum ( Figure 5A,B) convex, smooth, near 2/3 as long as broad, trapezoidal from dorsal view; anterior margin nearly straight; basal margin weakly sinuate, serrate and truncate on middle, and with a pair of deeply semi-circular notches nearly hind angles; disc evenly convex, impunctate. Scutellum triangular, longer than wide; middle part of anterior margin slightly concave, narrowed and slightly round apically, sloping upward apically, smooth and impunctate.
Elytron ( Figure 5A,B) nearly 2.5 times as long as broad, with weakly prominent humeri, parallel-sided, rounded-truncate apically. Disc of each with eleven regular rows of punctures, without any punctures between rows. truncate on middle, and with a pair of deeply semi-circular notches nearly hind angles; disc evenly convex, impunctate. Scutellum triangular, longer than wide; middle part of anterior margin slightly concave, narrowed and slightly round apically, sloping upward apically, smooth and impunctate.
Elytron ( Figure 5A-B) nearly 2.5 times as long as broad, with weakly prominent humeri, parallel-sided, rounded-truncate apically. Disc of each with eleven regular rows of punctures, without any punctures between rows.   Ventral surfaces of body with rather closely fine punctures and densely short pubescence. Prosternum rectangular, surface uneven, posterior margin straight and with long pubescence. Mesosternum small, rectangular, width about 1.3 times of length, surface coarse. Middle part of metasternum wrinkled. Pygidium with dense punctures and short pubescence.
Aedeagus ( Figures 5D-F and 6A-C) elongate, about 3.5 times as long as wide. Apex of median lobe nearly round, slightly narrower than middle, moderately curved in lateral view; with several pubescence on each side of apex, and with sparse punctures. Median orifice with median sclerite bending inwards above surface. Inner sac long and take almost 2/3 of total aedeagus. Tegmen Y-shaped, moderately sclerotized.
Female. Body more robust than male; antennae shorter and thinner than male, reaching middle part of elytra; posterior margin of pygidium more rounded. Spermatheca (Figures 5C and 6D) hook-shaped, acute-angled bending nearly 1/2 from apex, very acute at apex; duct weakly sclerotized, irregularly coiling. Rectal sclerites ( Figure 5G) moderately sclerotized, not connected between two rectangular sclerites on ventral side.
Distribution. China (Sichuan, Yunnan) ( Figure 9). Differential Diagnosis. This new species is similar to C. (s. str.) flavicaudis Tan [37] and both of their basal margin of pronotum with the same semi-circular notches, but it can be distinguished from the latter by the small-sized body, the underside almost entirely ochraceous and the apex of aedeagus wider than middle part, while the latter with large body, the underside with black band and the aedeagus slender with lateral margins almost parallel.
Etymology. The specific epithet is derived from the Latin words "incisus" and "dentatus" to indicate the basal margin of pronotum with a pair of deeply semi-circular notches.  Aedeagus ( Figure 5D-F and Figure 6A-C) elongate, about 3.5 times as long as wide. Apex of median lobe nearly round, slightly narrower than middle, moderately curved in lateral view; with several pubescence on each side of apex, and with sparse punctures. Median orifice with median sclerite bending inwards above surface. Inner sac long and take almost 2/3 of total aedeagus. Tegmen Y-shaped, moderately sclerotized.
Distribution. China (Sichuan, Yunnan) ( Figure 9). Differential Diagnosis. This new species is similar to C. (s. str.) flavicaudis Tan [37] and both of their basal margin of pronotum with the same semi-circular notches, but it can be distinguished from the latter by the small-sized body, the underside almost entirely ochraceous and the apex of aedeagus wider than middle part, while the latter with large body, the underside with black band and the aedeagus slender with lateral margins almost parallel.
Etymology. The specific epithet is derived from the Latin words "incisus" and "dentatus" to indicate the basal margin of pronotum with a pair of deeply semi-circular notches.      Description. Body ( Figure 7A,B) ochraceous. Head ochraceous, labrum, and labial palpus yellow; basal margin of clypeus reddish brown; mandibles black; antennae yellowish brown on first four segments, darkish brown on last seven. Pronotum with black basal margin. Scutellum yellow, anterior and posterior margins black, anterior region tinted with reddish brown; lateral margin brown. Elytron with reddish brown margins. Ventral surface of body largely darkly yellowish brown; lateral region of metasternum black; abdomen yellowish brown, and basal part of each segment black, legs yellowish brown, claws black.
Head more than one-half as broad as prothorax, nearly round in frontal outline, surface smooth. Eyes emarginated below middle, superior eye-lobes separated slightly wider than antennal insertions. Clypeus impunctate, apical region wrinkled, anterior margin slightly concave. Antennae of male long and broad, reaching apical 1/4 of elytra; 1st segment thick, clubbed, 2nd spherical, 2/5 as long as 1st; 3rd-4th slender, about equal in length, shorter than 5th, from 5th segment on somewhat equal in length, 5th-8th broadened and flatted, and last 3 segments long and thin.
Elytron ( Figure 7A,B) about 2.4 times as long as broad, humeri weakly prominent, glabrous, rounded-truncate apically. Disc of each with eleven somewhat oblique rows of fairly deep punctures; interspaces with densely fine punctures.
Ventral surfaces of body with rather densely fine punctures and shortly silver pubescence. Prosternum square, surface uneven, center of anterior margin slightly protruding, posterior margin with a pair of lobes. Mesosternum broad and small, square. The middle part of metasternum glabrous, with densely fine punctures, lateral region with densely pubescence. Pygidium with densely fine punctures and short pubescence. Claws with teeth ( Figure 7H).
Aedeagus ( Figure 7D-F and Figure 8A-C) elongate, clubbed, about 3.4 times as long as wide. Apex of median lobe arcuate, slightly narrower than middle, round at apex, weakly curved in lateral view; with several pubescence on each side of apex, impunctate. Median orifice with median sclerite bending inwards below surface. Inner sac rather slender. Tegmen Y-shaped, moderately sclerotized.
Female. Body more robust than male; antennae slightly shorter than male, coloration of ventral side of body darker than male, metasternum entirely black, central part of abdomen black, posterior margin of pygidium more broadened and rounded. Spermatheca ( Figures 7C and 8D) hook-shaped, acute-angled bending nearly 1/2 from apex, very acute at apex; duct weakly sclerotized, spirally coiling. Rectal sclerites ( Figure 7G) weakly sclerotized, connected between two rectangular sclerites on ventral side.
Distribution. China (Yunnan) (Figure 9). Differential Diagnosis. This new species is similar to C. (s. str.) gestroi Jacoby [32], but can be distinguished by the basal margin of each abdominal segment black and the other part yellow, with the median parts darker than the lateral.
Etymology. The specific epithet is derived from the Latin words "nigro-, flavus" and "venter"; it means that this new species has the abdominal coloration of yellow and black in an alternately arranged pattern.  Kimoto and Gressitt, 1981: 348 (as synonym of Cryptocephalus lacosus) [7,40].                    Remark. This species has variation in color, with some being bright yellow and others yellowish brown. The abdominal underside of some specimen tinged with black whereas other not.

Three New
After checking the materials in IZ-CAS under the name of C. nigrolimbatus Jacoby, 1890 [14], we found the species should be moved from the subgenus Burlinius to this subgenus and designed to this specie group, mainly based on the following characters: length of body ( Figure 15A,B) 3.8-4.6 mm; eyes and head large; aedeagus ( Figures 15D-F and 16A-C) simple, apically not prolonged into three or two processes.

Discussion
This study reports our taxonomic finding, with our attention concentrated on the Cryptocephalus heraldicus species group. The paper includes four new species, three species recorded for the first time in China, and other important changes in grouping some species in subgenus level. These results are of course the new contributions to the Chinese fauna of this megadiverse leaf beetle genus Cryptocephalus Geoffroy and definitely promotes the advances in the investigations on systematics, phylogeny, and zoogeography of the large subfamily Cryptocephalinae in the future.
As we pointed out in the Introduction part, the genus Cryptocephalus Geoffroy is megadiverse, with a wide geographical distribution in almost all zoogeographical regions of the world [1][2][3][4], and very difficult to get a taxonomic revising study including the whole genus of ca. 1800 species. As a matter of fact, no taxonomic study has been done in the past few decades [3], except for some that concentrated merely on local faunas [2,[4][5][6][7][8]43,44]. These publications are of course excellent contributions to this group. Our study contributed a new version of the species-group classification of the Chinese species and provided a new key to all the species groups found in China. In this point of view, this study is also a taxonomic review with its particular emphasis located upon the fauna of China, a country with very large territory and high biodiversity in the world and of great importance to fill the gap in word species inventories.
This study is concentrated on the leaf beetle subgenus Cryptocephalus Geoffroy from China and is the only contribution concerning this large genus in the last three decades after Tan (1992) [37]. Our results increase the species number of Cryptocephalus heraldicus species group to 30 in total. This new taxonomic finding may be of biological and systematic significance in filling gaps in the faunistic composition of the genus Cryptocephalus Geoffroy in China. This study is also one of our series studies on the leaf beetle subfamily Cryptocephalinae (including Cryptocephalini and Clytrini) [45][46][47][48][49].