Descriptions of Three New Species of the Genus Acerataspis Uchida, 1934 (Hymenoptera, Ichneumonidae, Metopiinae), with an Illustrated Identification Key to Extant Species

Simple Summary Acerataspis Uchida, 1934 is a genus of ichneumonid parasitoids distributed in the Oriental and Palaearctic regions. To date, only seven extant species have been recorded. The host of the genus is still not known. This paper reviews all valid extant species of the genus based on both morphological and molecular analyses and describes three new species. Abstract The Asian genus Acerataspis Uchida, 1934 is reviewed based on both morphology and DNA barcodes. Ten species are recognized in total, of which three species from Yunnan Province of China are described as new: Acerataspis maliae sp. nov., A. seperata sp. nov. and A. similis sp. nov. The male of A. fukienensis Chao, 1957 is described and illustrated for the first time. The genus is recorded from Thailand and Southeast Asia for the first time. An illustrated key to all known extant species is provided. With the supplement of DNA barcodes, a few diagnostic morphological characters are found useful in species identification.

To date, nothing is known about the biology of the genus. However, phylogenetic analysis of the subfamily with Acerataspis species included showed a close relationship with the genus Metopius Panzer, 1806 [16], which are known to be koinobiont, larvalpupal endoparasitoids of Lepidoptera, mainly Lasiocampidae, Erebidae, Notodontinae, Noctuidae, and Geometridae [6,17]. Members of both genera are coloured with black

Morphological Examination
In this study, 35 specimens representing ten morphospecies were examined from China, Myanmar, Thailand, and Russia, and ten morphospecies were recognized. Seven species were identified as previously described species and three are considered as new to science species as described below (Tables 1 and 2). Acerataspis clavata and A. fusiformis are recorded from Hong Kong and Thailand; these are the first documented records of the genus from these regions as well as Southeast Asia.

DNA Barcoding
The present study generated 27 CO1 sequences, representing six morphospecies with 642-684 bps. When sequences from GenBank and BOLD databases were compared using BLAST, only the sequences of Acerataspis clavata  received close matches with two sequences also labeled as A. clavata , but only share a 92.7% similarity. Genetic distances of the 27 sequences are provided in Table S1. Intraspecific distances of the CO1 sequences are generally less than 4%. Interspecific distances range between
Diagnosis. Fore wing length 7.0-10.0 mm. Face and clypeus evenly moderately convex (Figure 2A). Clypeal sulcus absent. Upper margin of face continued dorsally as an intra-antennal projection with a deep central groove. Temple very short, mostly flat ( Figure 2B). Occipital carina complete, but not reaching mandibular base ventrally, nor meeting hypostomal carina ( Figure 2C). Subocular sulcus absent. Mandible with upper tooth a little larger than lower tooth. Notaulus absent. Scutellum short, transverse, prolonged lateroposteriorly as a tooth ( Figure 2D). Propodeum with areas, anterior transverse carina present. Sternaulus broadly impressed. Metapleuron with juxtacoxal carina complete or incomplete. Fore wing with areolet sessile or petiolate, receiving 2m-cu vein before middle ( Figure 2E), hind wing with nervellus interrupted below middle. Middle tibia with a single slender spur in male, with two spurs in female. Hind tibia with two spurs. All claws pectinate ( Figure 2F). Metasoma clavate, T1-T3 with a pair of lateromedian longitudinal carinae from base to apex ( Figure 3A), T4 of some species also with a pair of short lateromedian longitudinal carinae on anterior base, T6 rounded and turned under ( Figure 3C,D). Ovipositor short, thin, tapered to apex, without a dorsal subapical notch ( Figure 3B).
Insects 2023, 14, x FOR PEER REVIEW 6 of 48 carinae from base to apex ( Figure 3A), T4 of some species also with a pair of short lateromedian longitudinal carinae on anterior base, T6 rounded and turned under ( Figure  3C,D). Ovipositor short, thin, tapered to apex, without a dorsal subapical notch ( Figure  3B). Comment. In previous studies of Metopiinae, the presence or absence of pectinae of tarsal claws were used to separate species in the genus Hypsicera [4,25]. However, this character was more or less overlooked or roughly described by authors in previous studies of Acerataspis. Based on the materials of Acerataspis from China, we found that the tarsal claw pectination of the female is a useful diagnostic character for species identification (although sometimes the pattern of pectination in the hind legs of some female specimens may vary between left hind leg and right hind leg). The proximal pecten of the claw is also very small and needs to be observed at high magnification.
Distribution. Oriental and Eastern Palaearctic regions (newly recorded from Hong Kong and Thailand).
Differential diagnosis. This species is very similar to A. fusiformis (Morley, 1913) in colour pattern, it is slightly different from the latter in having all tarsal claws densely pectinate (female fore tarsal claw of A. fusiformis with only three pectinae), area superomedia of male laterally expanded (based on the materials from China, area superomedia weakly convergent posteriorly), fore wing with 1cu-a postfurcal to M&RS (fore wing with 1cu-a opposite M&RS of A. fusiformis), metanotum usually black (except one specimen from Yunnan slightly brown) (metascutellum distinctly yellow in A. fusiformis).
Comments. The specimen (ID: SCAU-3013718) from Thailand with five pectinae on fore tarsal claw and apical transverse band on T4 interrupted dorsomedially is an unusual variation within species, and it was determined based on DNA barcoding. Variation. One specimen (specimen ID: SCAU-3013718) from Thailand with five pectinae on fore claw ( Figure 6D) and apical yellow band of T4 dorsomedially interrupted ( Figure 5B).
Distribution. Oriental and Eastern Palaearctic regions (newly recorded from Hong Kong and Thailand).
Differential diagnosis. This species is very similar to A. fusiformis (Morley, 1913) in colour pattern, it is slightly different from the latter in having all tarsal claws densely pectinate (female fore tarsal claw of A. fusiformis with only three pectinae), area superomedia of male laterally expanded (based on the materials from China, area superomedia weakly convergent posteriorly), fore wing with 1cu-a postfurcal to M&RS (fore wing with 1cu-a opposite M&RS of A. fusiformis), metanotum usually black (except one specimen from Yunnan slightly brown) (metascutellum distinctly yellow in A. fusiformis).
Comments. The specimen (ID: SCAU-3013718) from Thailand with five pectinae on fore tarsal claw and apical transverse band on T4 interrupted dorsomedially is an unusual variation within species, and it was determined based on DNA barcoding.      Diagnosis. Propedeum with anterior transverse carina joining area superomedia at middle, area dentipara densely and finely punctate. Fore wing ( Figure 8D) with 1cua postfurcal to M&RS; areolet sessile. T1 with a pair of carinae ( Figure 8B); T2 with three longitudinal median carinae ( Figure 8B), the median one obscure with apical half absent; T3 with three longitudinal carinae, the median one weak ( Figure 8B); T4 strongly punctate, without carina ( Figure 8E). Fore tarsal claw strongly pectinate, with 6-7 pectinae ( Figure 8C). Hind leg black, proximal half of tibia yellow with proximal base black ( Figure 7). Metanotum yellow. Metasoma ferruginous (Figure 7), with base of T1, base of T4, anterior half of T5, and T6 blackish to black.
Distribution. Oriental region [26]. Differential diagnosis. This species is very similar to A. clavata, especially in colour pattern, with differences between them as follows: A. cruralis with metascutellum yellow and T1 (except for the base black) to T4 (except for the extreme base black) mainly ferruginous, (A. clavata with metascutellum entirely black, T1-T4 black, apical margin with yellow marks or yellow band). Hind margin of T2 straight in A. cruralis (convex in its middle in A. clavata), fore claw weakly curved ( Figure 8C) in A. cruralis (more strongly curved in A. clavata) ( Figure 6A).
Distribution. Oriental region [26]. Differential diagnosis. This species is very similar to A. clavata, especially in colour pattern, with differences between them as follows: A. cruralis with metascutellum yellow and T1 (except for the base black) to T4 (except for the extreme base black) mainly ferruginous, (A. clavata with metascutellum entirely black, T1-T4 black, apical margin with yellow marks or yellow band). Hind margin of T2 straight in A. cruralis (convex in its middle in A. clavata), fore claw weakly curved ( Figure 8C) in A. cruralis (more strongly curved in A. clavata) ( Figure 6A).  Diagnosis. Propedeum with the area dentipara rugose. Fore tarsal claw ( Figure 9H) with 2-3 large teeth. Fore wing with 1cu-a opposite to M&RS ( Figure 10C). T1 and T2 with a pair of median longitudinal carinae ( Figure 9D). T3 with median carinae distinct on anterior half, obscure and weakened from middle to apex; T4 anteriorly with a pair of short lateromedian longitudinal carinae ( Figure 9C). Hind leg entirely black ( Figure 10B,D). Diagnosis. Propedeum with the area dentipara rugose. Fore tarsal claw ( Figure 9H) with 2-3 large teeth. Fore wing with 1cu-a opposite to M&RS ( Figure 10C). T1 and T2 with a pair of median longitudinal carinae ( Figure 9D). T3 with median carinae distinct on anterior half, obscure and weakened from middle to apex; T4 anteriorly with a pair of short lateromedian longitudinal carinae ( Figure 9C). Hind leg entirely black ( Figure 10B,D). Differential diagnosis. This species is similar to A. clavata in the colour pattern of metasoma, with differences between them as follows: A. formosana with hind tibia entirely black or blackish brown (hind tibia of A. clavata proximally with a white band), A. formosana with fore wing with 1cu-a vein opposite M&RS (fore wing with 1cu-a postfurcal to M&RS in A. clavata), T4 anteriorly with a pair of short lateromedian longitudinal carinae ( Figure 9C) (T4 without a pair of short lateromedian longitudinal carinae in A. clavata).

Insects 2023, 14, x FOR PEER REVIEW 21 of 48
Differential diagnosis. This species is similar to A. clavata in the colour pattern of metasoma, with differences between them as follows: A. formosana with hind tibia entirely black or blackish brown (hind tibia of A. clavata proximally with a white band), A. formosana with fore wing with 1cu-a vein opposite M&RS (fore wing with 1cu-a postfurcal to M&RS in A. clavata), T4 anteriorly with a pair of short lateromedian longitudinal carinae ( Figure 9C) (T4 without a pair of short lateromedian longitudinal carinae in A. clavata).  Differential diagnosis. This species is similar to A. clavata in the colour pattern of metasoma, with differences between them as follows: A. formosana with hind tibia entirely black or blackish brown (hind tibia of A. clavata proximally with a white band), A. formosana with fore wing with 1cu-a vein opposite M&RS (fore wing with 1cu-a postfurcal to M&RS in A. clavata), T4 anteriorly with a pair of short lateromedian longitudinal carinae ( Figure 9C) (T4 without a pair of short lateromedian longitudinal carinae in A. clavata).   Diagnosis. Area superomedia of propedeum medially with a transverse carina which divides the area into two parts: anterior transverse carina joining area superomedia at middle. Fore wing with 1cu-a opposite M&RS ( Figure 12A), areolet petiolate, T4 with a pair of carinae on anterior half ( Figure 12D).
Legs. Fore and hind tarsal claw with three pectinae ( Figure 12B,C). Metasoma. Coarsely and densely punctate. T1-T3 with a pair of paralleled lateromedian longitudinal carinae. T1 and T2 rugose punctate, with central area between median carinae irregularly rugose. Lateromedian longitudinal carinae of T2 connected by a transverse carina beyond middle. T3 with a weak carina between the median carinae, punctate, transverse, T4 with a pair of lateromedian longitudinal carinae on anterior half ( Figure 12D).
Metasoma ( Figure 14F). Strongly and coarsely punctate. Distribution. Oriental region. Comments. Chao [26] stated that the holotype of Acerataspis fukienensis was deposited in 'Fukien Agricultural College' (=Fujian Agricultural and Forestry University), but the type materials of this species are currently deposited in the Institute of Zoology, Chinese Academy of Science (Beijing).
Differential diagnosis. This species is similar to A. sinensis and A. szechuanensis Chao,1962, but can separated from these species by: fore wing with 1cu-a opposite M&RS (fore wing of A. sinensis and A. szechuanensis with 1cu-a distinctly postfurcal to M&RS); areolet petiolate (areolet of A. sinensis and A. szechuanensis sessile); fore and hind claws with three stout pectinae (with six fine pectinae in A. sinensis and A. szechuanensis); T4 with a pair of carinae on anterior half (T4 of A. sinensis without carina, of A. szechuanensis with a single short carina anteriorly); T4 with apical yellow narrow band medially interrupted (T4 of A. sinensis and A. szechuanensis with apical yellow band complete and largely broadly yellow); anterior transverse carina of propodeum joining area superomedia near middle (both A. sinensis and A. szechuanensis with anterior transverse carina joining area superomedia near posterior transverse carina).         Diagnosis. Fore wing with 1cu-a opposite M&RS, areolet sessile (Figures 17 and 18). Propodeum with costa joining area superomedia at middle ( Figure 19C). Fore tarsal claw of female with three pectinae ( Figure 19F). T1-T3 with a pair of median longitudinal carinae, with a weak longitudinal wrinkle in between. T4 without median carina. Antenna with scape entirely yellow. Metanotum yellow. Mid femur black with proximal base and apex yellow. Hind tibia with basal half yellow.
Wings. Fore wing with 1cu-a opposite to M&RS ( Figure 19D), areolet sessile and receiving 2m-cu before middle. Hind wing with nervellus interrupted at lower 0.3, distal abscissa of CU weakly pigmented.
Legs. All tarsal claws with three pectinae ( Figure 19F-H), fore tarsal claw with the middle pecten longer than the other two pectinae. Longer spur of hind tibia 0.67 times length of basitarsus. Hind femur 4.1 times its maximum width, 1.0 times the length of tibia.
Colour ( Figure 17A). Body black with yellow marks. Face with upper 0.6 yellow and lower 0.3 black. Mandible dark brown with extreme base black. Palpi whitish yellow. Scape yellow with laterally outer side black, pedicel dorsally black and ventrally yellow, flagellum dorsally blackish brown, ventrally fuscous on basal 0.6, and gradually becoming blackish brown on apical 0.3. Pronotum black with a yellow spot on posterior lateral corner. Tegula, parategula, scutellum, subtegular ridge and metanotum entirely yellow. Fore coxa dark brown with apex yellow, fore trochanter yellow, fore femur blackish on basal half and yellow on apical half, fore tibia and tarsus yellow; mid coxa blackish on basal 0.6 and yellow on apical 0.3, mid trochanter yellow, mid femur black with apical 0.2 yellow, mid tibia and tarsus yellow; hind coxa black, hind trochanter basally fuscous and apically yellow, hind femur black with extreme basal 0.1 whitish yellow, hind tibia with proximal 0.6 yellow (except the extreme base black) and apical 0.4 black, hind tarsus with 1-4 segments dark fuscous, 5th segment brownish yellow ( Figure 19E). Wings hyaline, wing base yellow, veins and pterstigma blackish brown. T1 laterally largely yellow, basal 0.3 and area between lateromedian longitudinal carinae black, T2 and T3 black with a pair of moderately large yellow marks on posterior lateral corner (extreme apical margin of T2 and T3 black), T4 (except for extreme apical margin black) and T5 apically with a yellow band, T6 black. Ovipositor sheaths fuscous.
Distribution. Oriental region (newly recorded from Hong Kong, Yunnan and Thailand). Comments. The head and antenna of the type was separated into two parts. We reviewed historical literature of the field notes of Leonardo Fea, who collected the holotype specimen of A. fusiformis during his travels to the Karen Hills of Bristish Burma [27,28]. The Karen Hills, or Kayah-Karen Mountains, is a large highland area in eastern Myanmar stretching from Shan Mountain southward to Tenassurin Mountain, although Fea had defined the Karen Hills as a restricted area between two tributaries of the Sittaung River (Thauk Ye Kupt and Paunglaung rivers) and the Nam Pawn River, a tributary of the Salween River. We reconstructed his sampling sites using his field diaries and supplementary maps [27,28] and estimate the approximate type locality of A. fusiformis to be 19 • There are some variations between some female specimens (n = 1, specimen ID: SCAU-3013715), propodeum with area dentipara densely punctate, lateromedian longitudinal carinae subparallel, area petiolaris transversely wrinkled with punctures in between. Yellow marks on T1-T4 larger (Figure 17), T1 largely yellow except for black anterior base, T2 with yellow marks not interrupted at middle (Figure 17). The pecten number of hind tarsal claws is different between left leg and right leg in one specimen (n = 1, specimen ID: SCAU-3011028) from Hainan Province of China (three pectinae on left hind claw and four pectinae on the right one). Variations in male specimens as follows: in SCAU-3013716, T4 with apical yellow band interrupted at middle (Figures 18 and 20H); in No. SCAU-3013717, with 1cu-a postfurcal to M&RS) ( Figure 20E).
Due to the brief original description of A. fusiformis and similar colour patterns of A. fusiformis and A. clavata, many specimens of A. fusiformis from different regions in previous studies [5,10,13,14,[29][30][31] were incorrectly determined as A. clavata . However, their CO1 genetic distances between A. fusiformis and A. clavata were 11-12% (Table S2). Therefore, their previous identification should be checked by using the main differential diagnostic characters: fore claw with three visible pectinae, fore wing with 1cu-a opposite to M&RS, and scutellum yellow in A. fusiformis; while in A. clavata, tarsal claw strongly pectinated, fore wing with 1cu-a postfurcal to M&RS, and scutellum black.
It is necessary to mention both A. fusiformis and A. clavata were collected in the same sampling sites in Thailand and Hong Kong. In Northern Thailand, the sampling site was in an old secondary Decteracarpus forest with Camellia sinensis var. assamica in the understory. There are similar communities with Camellia sinensis var. assamica around the type locality of A. fusiformis on the Karen Hills at Leonardo Fea's sampling sites [32].          3.4.6. Acerataspis maliae Liu & Chen sp. nov. (Figures 21-23 Diagnosis. Fore and mid tarsal claws with four pectinae, hind claw with seven pectinae; fore wing with 1cu-a slightly postfurcal to M&RS, areolet weakly sessile above. Scape yellow with a black stripe laterally ( Figure 22A).
Colour ( Figure 21A). Face mostly yellow (centrally brownish yellow) with lower 0.25 black. Mandible basally and apically black, medially brown. Palpi yellowish brown. Antenna dorsally fuscous, ventrally yellowish brown, scape ( Figure 22A) yellow with a lateral black stripe, pedicel and base of first flagellomere black. Tegula and subtegular ridge yellowish brown. Scutellum yellow with anterior 0.3 yellowish brown. Metasoma mainly black, T1-T3 posterior laterally with brownish yellow triangular spots, centrally interrupted by the lateromedian longitudinal carinae ( Figure 22E,F), T4-T5 posteriorly with a transverse brownish yellow band. Fore leg with coxa black, trochanter with outer side black and inner side brownish yellow, femur fuscous, outer side with basal 1/2 black, tibia and tarsus brownish yellow. Middle leg with coxa, trochanter and femur black, tibia fuscous with basal 0.4 brownish yellow, tarsus dark brown. Hind leg ( Figure 21) with coxa, trochanter and femur black, tibia blackish brown with proximal 0.3 brown, tarsus brown. All tibial spurs whitish yellow. Wings hyaline, veins blackish brown. Ovipositor sheath brownish yellow.

Distribution. Oriental region (China).
Etymology. The species is named after Prof. Li Ma, a hymenoptera taxonomist at Yunnan Agricultural University.
Differential diagnosis. The colour of the new species is very similar to A. clavata and A. fusiformis. It can be separated from A. clavata by fore and mid tarsal claws with four pectinae (fore and middle claws with more than six pectinae in A. clavata) and scape yellow dorsally (scape dorsally black in A. clavata). It differs from A. fusiformis by hind tarsal claw with seven pectinae (hind claw with three or four pectinae in A. fusiformis). The status of the new species is also supported by COI gene sequence; the genetic distances between this species and A. clavata and A. fusiformis range from 12.9% to 14.4%. (Table S2) Insects 2023, 14, x FOR PEER REVIEW 33 of 48 pectinae (fore and middle claws with more than six pectinae in A. clavata) and scape yellow dorsally (scape dorsally black in A. clavata). It differs from A. fusiformis by hind tarsal claw with seven pectinae (hind claw with three or four pectinae in A. fusiformis). The status of the new species is also supported by COI gene sequence; the genetic distances between this species and A. clavata and A. fusiformis range from 12.9% to 14.4%. (Table S2)   Diagnosis. Fore wing ( Figure 26D) with 1cu-a postfurcal to M&RS, areolet of fore wing sessile above. Propodeum with anterior transverse carina joining area superomedia at middle ( Figure 25D). All tarsal claws densely pectinate. T1-T4 with yellow marks posteriorly, T4 with apical transverse band interrupted dorso-medially ( Figure 25F).
Description. Female holotype. Body length 5.7 mm, fore wing length 4.3 mm. Head. Face ( Figure 24B) rugose punctate, punctures closed and forming some transverse wrinkles, combined face and clypeus 1.3 times as high as wide. Mandible slightly twisted, with upper tooth longer than lower tooth, mandible with a flange-like projection subasally. Malar space 0.5 times the width of mandibular base. Head 1.6 times as wide as Diagnosis. Fore wing ( Figure 26D) with 1cu-a postfurcal to M&RS, areolet of fore wing sessile above. Propodeum with anterior transverse carina joining area superomedia at middle ( Figure 25D). All tarsal claws densely pectinate. T1-T4 with yellow marks posteriorly, T4 with apical transverse band interrupted dorso-medially ( Figure 25F).
Description. Female holotype. Body length 5.7 mm, fore wing length 4.3 mm. Head. Face ( Figure 24B) rugose punctate, punctures closed and forming some transverse wrinkles, combined face and clypeus 1.3 times as high as wide. Mandible slightly twisted, with upper tooth longer than lower tooth, mandible with a flange-like projection subasally. Malar space 0.5 times the width of mandibular base. Head 1.6 times as wide as long. Gena strongly narrowed behind eyes. POL:OD:OOL = 6:6:5. Antenna with 47 flagellomeres, first flagellomere 1.8 times as long as its apical width, 1.4 times as long as the second. Occiput strongly punctate and setiferous. Occipital carina complete.
Legs. Fore femur swollen, 2.5 times as long as its maximum width; fore tarsal claw ( Figure 26A) densely pectinate, with seven pectinae, basitarsus 0.8 times the combined length of tarsomeres [2][3][4][5]. Middle femur 3.2 times as long as its maximum width, middle claw densely pectinate ( Figure 26B). Hind femur ( Figure 25E) 4.0 times as long as its maximum width, the longer tibial spur 0.7 times the length of basitarsus. Hind tarsal claw densely pectinate, teeth of equal size ( Figure 26C). Metasoma ( Figure 25F). Strongly punctate. T1-T3 with a pair of latero-median carinae; area between latero-median carinae of T1 weakly transversely rugose, that of T2 weakly rugose, and with a longitudinal wrinkle reaching to posterior 0.8 of T2, that of T3 weakly rugose and with a longitudinal wrinkle reaching to posterior 0.8 of T3. Dorso-lateral carina of T1 absent. T4 densely punctate, medially longitudinally convex, without carina. T1 1.3 times as long as its apical width, T2 0.7 times as long as its apical width, T3 0.5 times as long as its apical width. T5 and T6 strongly punctate reticulate. Ovipositor sheath as long as hind basitarsus.
Colour. Body black with white maculations ( Figure 24A). Face with upper 0.8 white (color altered after DNA extraction), lower 0.2 black. Mandible black. Palpi whitish. Antenna black, inner side of scape whitish. Tegula and subtegular ridge white. Scutellum white. Metanotum black. Fore coxa black with anterior side white; trochanter white, dorsally with a brown mark on basal 0.6; fore femur anteriorly white, posteriorly dark brown with apex white; fore tibia white, inner side with basal 0.7 dark brown; tarsus dark brown except for white basitarsus. Middle coxa black with white spot on anterior side; mid trochanter white, dorsally with basal 0.8 dark brown; mid femur black except for proximal base and extreme apex white; mid tibia white, inner side with basal 0.6 dark brown, mid tarsus with basitarsus mostly white (extreme apex dark brown), 2nd-5th tarsomeres dark brown. Hind coxa black, trochanter black with anterior side dark brown, hind femur black with proximal base white; tibia with proximal base and apical half black, basal half white; tarsus black. All tibial spurs white. T1 with a pair of large triangular white marks laterally; T2 with a pair of white marks on lateral posterior half; T3 with a medially interrupted subapical transverse white band; T4 with a medially interrupted subapical transverse white band; T5 with a complete transverse white band subapically. Wings hyaline, veins and pterostigma blackish brown.
Distribution. Oriental region (Yunnan province of China). Etymology. The specific name is derived from Latin separatus, referring to the separated maculation of T4.
Comments. This species can be separated from other congeneric species mainly by combinations of: T4 with separated maculations, densely pectinate claws, and fore wing with 1cu-a postfurcal to M&RS. This new species and A.clavata from Thailand (SCAU-3013718) share the separated maculation of T4, with differences between them as follows: A. separata sp. nov. with scape dorsally black (scape dorsally yellow in Thailand A. clavata) and metapleuron with three foveae on anterior margin (metapleuron with only two foveae in Thailand A. clavata). This new species was also supported by the interspecific distance of the CO1 gene.  [27][28][29]. Similar to female, except: body length 7.1 mm, fore wing length 5.4 mm. Epicnemial carina strong, reaching to upper end of mesopleuron ( Figure 28B). Propodeum ( Figure 28E) with area dentipara strongly rugose, area superomedia rugulose. Tarsal claws strongly pectinate ( Figure 29A-C). White marks on T1-T3 smaller than female ( Figure 28F). Scutellum white.
Distribution. Oriental region (Yunnan province of China). Etymology. The specific name is derived from Latin separatus, referring to the separated maculation of T4.
Comments. This species can be separated from other congeneric species mainly by combinations of: T4 with separated maculations, densely pectinate claws, and fore wing with 1cu-a postfurcal to M&RS. This new species and A.clavata from Thailand (SCAU-3013718) share the separated maculation of T4, with differences between them as follows: A. separata sp. nov. with scape dorsally black (scape dorsally yellow in Thailand A. clavata) and metapleuron with three foveae on anterior margin (metapleuron with only two foveae in Thailand A. clavata). This new species was also supported by the interspecific distance of the CO1 gene.         Diagnosis. This species can be distinguished from other species by the following combined characters: tarsal claws ( Figure 32A-C) weakly and sparsely pectinate, fore tarsal claw with three pectinae, mid tarsal claw with four pectinae, hind tarsal claw with four pectinae (basal two slightly bigger than the apical two); fore wing with 1cu-a opposite M&RS ( Figure 31D), areolet sessile and receiving 2m-cu before middle; metanotum black; hind leg black, hind tibia with a narrow whitish band ( Figure 31E); T4 without carina ( Figure 31F).
Head. Face rugose punctate ( Figure 30B), punctures close, some forming transverse wrinkles; moderately densely setose; combined face and clypeus 1.5 times as high as wide. Mandible slightly twisted, with upper margin longitudinally convex, upper tooth longer than the lower one. Malar space 0.5 times as long as the mandibular basal width. Head in dorsal view 2.2 times as wide as long. Temple very short, strongly narrowed behind eyes, 0.2 times as long as eye in dorsal view. POL:OD:OOL = 10:10:6. Vertex sloping vertically from posterior ocellus. Antenna with 58 flagellomeres, first flagellomere 1.1 times as long as its apical wide, 1.25 times as long as the second flagellomere.
Mesosoma. Pronotum ( Figure 31A) with dorsal 0.3 strongly coarsely punctate and setose; lower 0.6 polished and glabrous, with several transverse carinae along the posterior margin (crenulate). Mesoscutum ( Figure 31B) coarsely and closely punctate, lateral side of scutum with punctures closed and more or less forming wrinkles. Scuto-scutellar groove deeply crenulate, medially with three short longitudinal carinae. Scutellum transverse, punctate, lateral posterior corner with a sharp projection. Propodeum with area superomedia rectangular, 1.1 times as long as wide, anterior half weakly rugose, posterior Diagnosis. This species can be distinguished from other species by the following combined characters: tarsal claws ( Figure 32A-C) weakly and sparsely pectinate, fore tarsal claw with three pectinae, mid tarsal claw with four pectinae, hind tarsal claw with four pectinae (basal two slightly bigger than the apical two); fore wing with 1cu-a opposite M&RS ( Figure 31D), areolet sessile and receiving 2m-cu before middle; metanotum black; hind leg black, hind tibia with a narrow whitish band ( Figure 31E); T4 without carina ( Figure 31F).
Head. Face rugose punctate ( Figure 30B), punctures close, some forming transverse wrinkles; moderately densely setose; combined face and clypeus 1.5 times as high as wide. Mandible slightly twisted, with upper margin longitudinally convex, upper tooth longer than the lower one. Malar space 0.5 times as long as the mandibular basal width. Head in dorsal view 2.2 times as wide as long. Temple very short, strongly narrowed behind eyes, 0.2 times as long as eye in dorsal view. POL:OD:OOL = 10:10:6. Vertex sloping vertically from posterior ocellus. Antenna with 58 flagellomeres, first flagellomere 1.1 times as long as its apical wide, 1.25 times as long as the second flagellomere.
Legs. Fore femur swollen, 1.88 times as long as its maximum width; fore tarsal claw sparsely pectinate, with three or four pectinae ( Figure 32A), second to fifth tarsomeres ventrally flattened, shortly and densely pubescent. Middle femur 3.3 times as long as its maxium width, middle tarsal claw with four pectinae ( Figure 32B). Hind femur ( Figure 31E) 5.0 times as long as its maximum width, longest spur of hind tibia 0.63 times the length of basitarsus. Hind claw with four pectinae (Figure 32C), the basal two slightly longer and stronger than the apical two pectinae.
Colour. Body black with yellow maculation ( Figure 30A). Face with upper 0.6 yellow (colour altered following DNA extraction), with lower 0.3 black. Mandible blackish brown with teeth apically lighter. Palpi yellowish brown. Antenna ventrally fuscous and dorsally blackish brown, scape yellow, laterally blackish, pedicel and annellus blackish. Tegula brown. Mesoscutum with posterior lateral corner yellow. Scutellum reddish brown. Subtegular ridge reddish. Wings hyaline, veins and pterostigma blackish brown. T1-T3 each with a pair of yellow spots subapically, the yellow maculation of T1 and T2 weakly connected medially, that of T3 interrupted dorso-medially ( Figure 31F). T4 and T5 subapically with a yellow band. All coxae black (extreme apex of fore coxa brown); fore leg with trochanter dark brown, femur dark brown with apex yellowish brown, tibia and tarsus yellowish brown; middle leg with trochanter blackish brown, femur black, tibia blackish brown with basal 0.2 and apex yellowish brown; tarsus fuscous. Hind leg black, (except tibia subasally with a yellowish-brown band). Ovipositor sheath yellowish brown.
Distribution. Oriental region (China, Yunnan Province). Differential diagnosis. This new species differs from A. clavata by fore wing with 1cua opposite to M&RS (postfurcal to M&RS of A. clavata), fore tarsal claw with 3-4 pectinae (with 8-10 pectinae in A. clavata). The new species is also quite similar to A. fusiformis, different in hind tarsal claw with four pectinae (hind tarsal claw with three pectinae in A. fusiformis) and black metanotum (metanotum yellow in A. fusiformis).
Distribution. Oriental and Palearctic regions [6]. sinensis; however, as there is no molecular data for either species, the status of Acerataspis szechuanensis is reserved.     without white band basally. Distribution. Oriental region (China, Sichuan Province). Differential diagnosis. This species is very similar to A. sinensis in colour pattern; it is only different from A. sinensis in having scutellum black (yellow in A. sinensis) and recticulate punctation (normal punctuation in A. sinensis). It is probably a variant of A. sinensis; however, as there is no molecular data for either species, the status of Acerataspis szechuanensis is reserved. Figure 35. Acerataspis szechuanensis Chao, holotype, female, lateral view (Image: Huang Zhengzhong). without white band basally.
Distribution. Oriental region (China, Sichuan Province). Differential diagnosis. This species is very similar to A. sinensis in colour pattern; it is only different from A. sinensis in having scutellum black (yellow in A. sinensis) and recticulate punctation (normal punctuation in A. sinensis). It is probably a variant of A. sinensis; however, as there is no molecular data for either species, the status of Acerataspis szechuanensis is reserved. Figure 35. Acerataspis szechuanensis Chao, holotype, female, lateral view (Image: Huang Zhengzhong).

Discussion
Some studies have suggested that ichneumonid wasps have some characteristics-such as frequently occurring genetic introgression caused by Wolbachia endosymbionts and the low evolutionary rate of the CO1-marker-that make the relation between morphospecies and molecular species delimitation more complicated than in other Hymenoptera [33][34][35]. Therefore, the combination of morphological, molecular and some other characters have been proposed as a reliable method for species delimitation. In this study, we revised the species of Acerataspis using an integrative approach combining morphology and DNA barcoding techniques. In general, the morphological and molecular data complemented each other quite well in delimiting species. Compared with the CO1 sequences of A. clavata newly generated in this study, the two sequences labeled as A. clavata downloaded from GenBank have an 8% basepair difference, suggesting that these two sequences may represent a different species or a haplotype given that these two sequences-together with