Revision of the Assassin Bug Genus Sigicoris stat. nov. Based on Morphological Study and Molecular Phylogeny (Heteroptera: Reduviidae: Peiratinae)

Simple Summary The members of the Reduviidae family are generally known as “assassin bugs” due to their predatory habits. Peiratinae is one of the largest subfamilies of Reduviidae with a cosmopolitan distribution. Based on the morphological examination on type specimens and other peiratine material from New Guinea, as well as the result of a molecular phylogenetic analysis using COI, 16S and 18S genes, the subgenus Ectomocoris (Sigicoris) Miller, 1958 is elevated to genus level and revised. Four species are recognized and keyed, including three new combinations: S. brumalis comb. nov., S. gracilis comb. nov., S. sexguttatus comb. nov. and one new species, S. dominiqueae sp. nov. The lectotype is designated for Brachysandalus sexguttatus. Pirates concinnus syn. nov. is treated as the junior synonym of S. sexguttatus comb. nov. The systematic relationships, diagnosis, distribution and habitat of this genus are also discussed. Abstract Peiratinae is a cosmopolitan subfamily within Reduviidae with more than 300 known species in 34 genera. There are also some taxa endemic to islands, but their taxonomic status and biology require further study. After examining type specimens of the peiratine species distributed in New Guinea, we found that some of them share many morphological characters, though they were previously assigned in different genera. The phylogenetic analysis based on cytochrome oxidase I, 16S ribosomal RNA and 18S ribosomal RNA genes involving 38 species in 25 genera also supports the result of the morphological study that these species should be involved in a separate genus. In the present study, the subgenus Ectomocoris (Sigicoris) Miller, 1958 is elevated to genus level, Sigicoris stat. nov. Three new combinations, S. brumalis comb. nov., S. gracilis comb. nov., S. sexguttatus comb. nov. and one new species, S. dominiqueae sp. nov. are described or redescribed. The lectotype of Brachysandalus sexguttatus is designated, and Pirates concinnus syn. nov. is treated as the junior synonym of S. sexguttatus comb. nov. A key is provided to separate the four species of this genus. The systematic relationships, diagnosis, distribution and habitat of Sigicoris stat. nov. are briefly discussed.


Introduction
Being one of the largest subfamilies in Reduviidae, Peiratinae compromises more than 300 valid species in 34 genera [1][2][3][4][5][6][7][8][9][10][11]. Most peiratine species are predators living on the ground. They are usually nocturnal, and hide in rock crevices, decomposing tree trunks and other cryptic microhabitats during the daytime and become active at night [6]. Phylogenetic studies on Peiratinae have been relatively limited and mainly focus on interspecific relationships within the genus [12][13][14][15][16]. More recently, the use of molecular data has contributed much to clarifying unresolved taxa and carrying out phylogenetic

Sequencing and Assembly
An Illumina TruSeq library was prepared for each species to ensure the sequencing quality. All libraries were prepared with an average insert size of 350 bp and sequenced using the Illumina HiSeq 2500 platform with 150 bp paired-end reads. Raw reads were trimmed of adapters using Trimmomatic [24]. Prinseq version 0.20.4 [25] was used to remove short and low-quality reads with poly-Ns (>15 bp Ns), or >75 bp bases with a quality score ≤3. The remaining reads were de novo assembled using IDBA-UD [26], with minimum and maximum k values of 45 and 145 bp, respectively.
The contamination and DNA degradation of some museum specimens made the sequencing results of each species uneven. We finally chose three gene fragments with high species coverage viz. the nuclear ribosomal RNA (rRNA) gene 18S and the mitochondrial genes cytochrome oxidase I (COI) and 16S rRNA to avoid too much missing data in the dataset. Using the gene fragments of Peiratinae obtained from GenBank as bait sequences, the above three genes of each newly sequenced species were identified from corresponding assemblies by blast searches.

Phylogenetic Analysis
Combining newly sequenced genes and sequences available from GenBank, the ingroup for the phylogenetic analysis included 38 peiratine species representing 25 genera; two other assassin bugs, Sphedanolestes impressicollis (Stål, 1861) (Harpactorinae) and Triatoma rubrofasciata (De Geer, 1773) (Triatominae), were selected as outgroups (Supplemental Table S2). As our examined specimens of Ectomocoris gracilis Miller, 1958 were all type specimens and there were no additional specimens for DNA extraction, only the other three putative species of Sigicoris stat. nov. (E. brumalis Miller, 1958, Sigicoris dominiqueae sp. nov., and Brachysandalus sexguttatus Stål, 1866) were included in the phylogenetic analysis.
Sequences of COI were aligned using codon-based multiple alignments under the mafft algorithm [27] implemented in the translatorx online platform with the L-INS-i strategy and default settings [28]. Sequences from each of the two rRNA genes were aligned separately using the mafft v.7.0 online server with G-INS-i strategy [29]. All alignments were then checked manually in MEGA v.7.0. [30]. The dataset, which consisted of 3284 bp, was concatenated with complete COI (1533 bp), complete 16S (1280 bp) and partial 18S (471 bp). The 18S fragments of nine peiratine species and partial COI fragment of Ectomocoris quadriguttatus (Fabricius, 1781) (for details, see Supplemental Table S2) were not available from the assemblies and thus treated as missing data.
Phylogenetic trees were constructed under maximum likelihood (ML) methods using IQ-TREE web server [31]. The dataset was partitioned by gene. The best evolutionary model for each partition was selected under the corrected Akaike Information Criterion (AIC) in IQ-TREE as GTR + F+I + G4 (for COI and 16S) and TVMe + I+G4 (for 18S). The ML tree was selected with IQ-TREE by an ultrafast bootstrap approximation approach with 10,000 replicates.

Morphological Study
Methods of male genitalia dissection, image capturing and processing followed those of Liu et al. [8][9][10]. Measurements were obtained using a calibrated micrometer. Body length represented the distance between the apex of the head and the tip of the abdomen in resting condition. The distribution map was built using the online version of Sim-pleMappr [32]. The distribution data were based on our examination of museum specimens, supplemented by data from Miller [23]. Morphological terminology mainly followed Lent and Wygodzinsky [33] and Liu et al. [8][9][10].

Phylogenetic Analysis
The phylogenetic tree under ML analysis is shown in Figure 1. The reconstruction recovers the monophyly of Peiratinae and the genera with more than two representa-  1843. Ectomocoris Mayr, 1865 is recovered as polyphyletic with respect to Ectomocoris (Sigicoris). The three putative Sigicoris species, Ectomocoris brumalis, Brachysandalus sexguttatus and the new species described in the present study are grouped together (highlighted in red in Figure 1) with high support (node support value = 100), and they form a separate branch, which is a sister group to the clade (Lamotteus Villiers, 1948+ Parapirates Villiers, 1959. To better resolve the relationship between Sigicoris and Ectomocoris, we include the type species of Ectomocoris, E. quadriguttatus, in the taxon sampling. However, Sigicoris is not closely related to the Ectomocoris clade; instead, Ectomocoris is recovered as the sister group of Peirates. As to the genus Brachysandalus Stål, 1866, to which B. sexguttatus originally belongs, it forms the sister group of the genus Catamiarus Amyot and Serville, 1843 and is far from Sigicoris in the topology. Hence, the results of the phylogenetic analysis based on molecular data support the genus status of Sigicoris stat. nov. and further confirm the new combinations of S. brumalis comb. nov. and S. sexguttatus comb. nov.

Phylogenetic Analysis
The phylogenetic tree under ML analysis is shown in Figure 1. The reconstruction recovers the monophyly of Peiratinae and the genera with more than two representative species: Androclus Stål, 1863; Peirates Serville, 1831; Fusius Stål, 1862; Phalantus Stål, 1863 and Lestomerus Amyot and Serville, 1843. Ectomocoris Mayr, 1865 is recovered as polyphyletic with respect to Ectomocoris (Sigicoris). The three putative Sigicoris species, Ectomocoris brumalis, Brachysandalus sexguttatus and the new species described in the present study are grouped together (highlighted in red in Figure 1) with high support (node support value = 100), and they form a separate branch, which is a sister group to the clade (Lamotteus Villiers, 1948+ Parapirates Villiers, 1959. To better resolve the relationship between Sigicoris and Ectomocoris, we include the type species of Ectomocoris, E. quadriguttatus, in the taxon sampling. However, Sigicoris is not closely related to the Ectomocoris clade; instead, Ectomocoris is recovered as the sister group of Peirates. As to the genus Brachysandalus Stål, 1866, to which B. sexguttatus originally belongs, it forms the sister group of the genus Catamiarus Amyot and Serville, 1843 and is far from Sigicoris in the topology. Hence, the results of the phylogenetic analysis based on molecular data support the genus status of Sigicoris stat. nov. and further confirm the new combinations of S. brumalis comb. nov. and S. sexguttatus comb. nov.

Taxonomy
Order Diagnosis: Members of the genus can be recognized among Peiratinae by the following combination of characteristics: head with anteclypeus raised, postocular part ellipsoidal; width of eye shorter than width of interocular space; 1 + 1 tubercles of neck prominent, surface granulose; anterior lobe of pronotum with an elliptical depression on posterior portion, stripes nearly invisible; disc of scutellum broad and granulose, scutellar process slender, apex slightly directed obliquely backward in lateral view; anterior half of metapleural sulcus slightly curved, posterior half nearly straight; ventral surfaces of fore and mid femora with rows of tiny denticles, and each denticle bearing an erect, long seta apically; fore tibia slightly recurved in apical half, with fossula spongiosa occupying at least half of tibial length ventrally; mid tibia with fossula spongiosa occupying at least 1/3 of ventral surface; hemelytron with Cu on corium reduced, Cu and Pcu on membrane short and nearly straight, inner cell relatively short and somewhat quadrilateral.
Description: Coloration. Mostly brown to blackish brown, sometimes with yellowish white spots on hemelytron and femora and yellowish spots on connexivum.
Structure. Macropterous form. Most of body surface covered with scattered setae of varying lengths; costal margin of corium densely covered with short pubescence; ventral surface of abdomen covered with procumbent pubescence (Figures 2, 3 Figure 4A,C, Figure 8A,C, Figure 12A,C and Figure 16A,C).

Systematic relationships of Sigicoris stat. nov.
We make the first attempt of the molecular phylogenetic analysis of the whole subfamily, with the taxon sampling containing over 70% of the peiratine genera (25/35) based on the COI, 16S and 18S genes. The tree topology helps us further confirm the monophyly and genus status of Sigicoris stat. nov., which indicates the application of molecular data in taxonomic revision. Sigicoris gracilis comb. nov. is not included in the phylogenetic analysis due to the specimen limitation. Sigicoris gracilis comb. nov. is the type species of Sigicoris and can be included in this genus as it shares the morphological characters as described below and the endemic distribution (New Guinea) of the other Sigicoris stat. nov. species.
Sigicoris was first proposed as a subgenus of Ectomocoris with two species, E. (Sigicoris) brumalis and E. (Sigicoris) gracilis, while some members of Sigicoris stat. nov. were originally assigned in Brachysandalus or Peirates. Sigicoris stat. nov., indeed, shares some characters with these three genera, such as the denticles on the ventral surfaces of the fore and mid femora with Brachysandalus, the similar length ratio of the anterior lobe of the pronotum to the posterior lobe with Peirates and the prominent fossula spongiosa with Ectomocoris. However, the reduced Cu on the corium and the short and nearly straight Pcu and Cu resulting in the relatively short and somewhat quadrilateral inner cell on the membrane make Sigicoris stat. nov. quite unique even in the whole Peiratinae. Except the characters listed above, Sigicoris stat. nov. can also be distinguished from Brachysandalus by the shape of the fore tibia (slightly recurved in the apical half in Sigicoris stat. nov. vs. clavate and gradually thickened to the apex in Brachysandalus), and from Peirates by the less distinct and even nearly invisible sculpture on the pronotum. As for the genus Ectomocoris to which Sigicoris used to belong, the latter could be separated from the former by the smaller eye, the less thickened fore femur, the less elongated anterior lobe of the pronotum and the shape of the abdomen in males (the posterior margin of the abdomen nearly straight with middlemost feebly concave onwards in Sigicoris stat. nov. vs. the posterior margin of the abdomen arcuate in Ectomocoris). In addition, the three sampled Sigicoris species are grouped together in our phylogenetic tree and not nested within the Ectomocoris clade that includes the type species E. quadriguttatus. The results of the morphological comparison and molecular phylogenetic analysis both demonstrate that Sigicoris should be separated from Ectomocoris as a valid genus.
So far, the only two species in Ectomocoris distributed in New Guinea are E. mimomyrmix and E. olthofi. We examined the apterous female holotype of E. mimomyrmix deposited in NHM (label information: "Holotype" disc // red-margined "Type" disc // "PAPUA:  and most of the legs (except one mid femur and tibia stuck on the card) are missing and the thorax is broken and glued together. Thus, more specimens, especially male and macropterous ones, are needed to further confirm the status of this species. We also examined one male paratype of E. olthofi deposited in NHM (label information: yellowmargined "Paratype" disc // "Neth. American New Guinea Exedit. Bernhard camp, 50 m, 2 ix. 1938, J. Olthof" // "Ectomocoris olthofi sp. n. (paratype) N.C.E.Miller det. 1956" // "NHMUK 013585956") and confirmed its status due to the typical diagnostic characters of Ectomocoris such as the anterior lobe of the pronotum more than twice longer than the posterior lobe, the strongly thickened fore femur and the fossula spongiosa nearly occupying the whole ventral surfaces of the fore and mid tibiae. Therefore, currently there are four peiratine genera distributed in New Guinea: Ceratopirates, Ectomocoris, Sigicoris stat. nov. and Sirthenea.   Diagnosis: Body blackish brown in large part; width of interocellar space subequal to width of ocellus; first visible segment of rostrum longer than third segment; pronotum with anterior margin slightly concave, collar process prominent, lateral pronotal angle narrowly rounded; fore tibia with fossula spongiosa occupying 2/3 of tibial length, mid tibia with fossula spongiosa occupying half of tibial length; median pygophore process long, slender and straight, apex sharp, slightly oblique to left side in caudal view, base of inner margin serrated in lateral view; parameres subtriangular with inner margin concave; lower half of inner margin of lateral phallothecal sclerite with two processes, one upward and one downward. narrowly rounded; fore tibia with fossula spongiosa occupying 2/3 of tibial length, mid tibia with fossula spongiosa occupying half of tibial length; median pygophore process long, slender and straight, apex sharp, slightly oblique to left side in caudal view, base of inner margin serrated in lateral view; parameres subtriangular with inner margin concave; lower half of inner margin of lateral phallothecal sclerite with two processes, one upward and one downward.  Redescription: Macropterous form (Figures 2 and 3). Coloration. Blackish brown. Antennae, third visible segment of rostrum and tarsi brown (Figures 2 and 3); hemelytron dark brown, with most of clavus and area between Pcu and Cu on corium paler, base of costal area of membrane with a diffuse pale brown stripe ( Figure 4F). Structure. Antennae, head, disc of scutellum, pleura, sterna, coxae, ventral surfaces and apex of femora, tibiae, lateral margin of corium, eighth abdominal sternite and genitalic part densely covered with golden, procumbent, short pubescence; first and second antennal segments, lateral margins of head and pronotum, femora and tibiae covered with brown, suberect to erect setae of varying lengths; apex of dorsal surfaces of tibiae and ventral surfaces of tarsi densely covered with yellow to yellowish brown, suberect setae; venter of abdomen sparsely covered with golden, long pubescence (Figures 2 and 3). Structure. Antennae, head, disc of scutellum, pleura, sterna, coxae, ventral surfaces and apex of femora, tibiae, lateral margin of corium, eighth abdominal sternite and genitalic part densely covered with golden, procumbent, short pubescence; first and second antennal segments, lateral margins of head and pronotum, femora and tibiae covered with brown, suberect to erect setae of varying lengths; apex of dorsal surfaces of tibiae and ventral surfaces of tarsi densely covered with yellow to yellowish brown, suberect setae; venter of abdomen sparsely covered with golden, long pubescence (Figures 2 and 3). Head length about 1.29 times as long as width in male and about 1.38 times as long as width in female; median short sulcus on interocular space deep ( Figure 4A); width of interocellar space slightly longer than width of ocellus ( Figure 4A); first visible segment of rostrum about 1.15 times longer than third segment ( Figure 4B). Pronotum with anterior margin slightly concave, collar process prominent ( Figure 4A); anterior lobe of pronotum about 1.59 times longer than posterior lobe in male and about 1.40 times longer than posterior lobe in female; lateral pronotal angle narrowly rounded ( Figure 4A). Fore tibia with fossula spongiosa occupying 2/3 of tibial length ( Figure 4D), mid tibia with fossula spongiosa occupying half of tibial length ( Figure 4E). Head length about 1.29 times as long as width in male and about 1.38 times as long as width in female; median short sulcus on interocular space deep ( Figure 4A); width of interocellar space slightly longer than width of ocellus ( Figure 4A); first visible segment of rostrum about 1.15 times longer than third segment ( Figure 4B). Pronotum with anterior margin slightly concave, collar process prominent ( Figure 4A); anterior lobe of pronotum about 1.59 times longer than posterior lobe in male and about 1.40 times longer than posterior lobe in female; lateral pronotal angle narrowly rounded ( Figure 4A). Fore tibia with fossula spongiosa occupying 2/3 of tibial length ( Figure 4D), mid tibia with fossula spongiosa occupying half of tibial length ( Figure 4E).
Male genitalia asymmetric ( Figure 5). Pygophore oval in ventral view ( Figure 5A); median pygophore process long, slender and straight, apex sharp ( Figure 5A-C), slightly oblique to left side in caudal view ( Figure 5B), base of inner margin serrated in lateral view ( Figure 5C). Parameres subtriangular with inner margin concave, left paramere ( Figure 5D) slightly longer and slenderer than right paramere ( Figure 5E). Phallus with phallobase strongly sclerotized, basal plate bridge feebly curved and slightly longer than basal plate ( Figure 5F); pedicel nearly straight and shorter than basal plate ( Figure 5H,I). Dorsal phallothecal sclerite distinctly sclerotized, broad and flat ( Figure 5F,H,I); lateral phallothecal sclerite moderately sclerotized, lower half of inner margin with two processes, one upward and one downward ( Figure 5I). Apical portion of endosoma with a sacciform process, surface of which is covered with rows of tiny spine-like tubercles ( Figure 5F,H).
Measurements Diagnosis: Body reddish brown to dark brown, pronotum with anterior lobe blackish brown and posterior lobe dark brown; width of interocellar space longer than width of ocellus; third visible segment of rostrum longer than first segment; pronotum with anterior margin nearly straight, collar process prominent, lateral pronotal angle rounded; fore tibia with fossula spongiosa occupying half of tibial length, mid tibia with fossula spongiosa occupying 1/3 of tibial length; median pygophore process long and extremely slender, apex sharp, nearly vertical in caudal view and curved in lateral view; parameres sickle-shaped; phallobase and dorsal phallothecal sclerite less sclerotized; lower half of inner margin of lateral phallothecal sclerite with two upward processes. Insects 2022, 13, x FOR PEER REVIEW 13 of 27 Description: Macropterous form (Figures 6 and 7). Coloration. Reddish brown to dark brown. Head, anterior lobe of pronotum, scutellum, pleura and sterna blackish brown; third and fourth segments of antenna brown; tarsi yellowish brown (Figures 6 and 7); hemelytron dark brown, with apical half of clavus, area between Pcu and Cu on corium and apical portion of membrane paler, base of costal area of membrane with a diffuse pale brown stripe ( Figure 8F).
Structure. Antennae, marginal area of head, disc of scutellum, pleura, sterna, coxae, ventral surfaces and apex of femora, tibiae, lateral margin of corium and venter of abdomen densely covered with golden, procumbent, short pubescence; first and second antennal segments, lateral margins of head and pronotum, femora and tibiae covered with brown, suberect to erect setae of varying lengths; apex of dorsal surfaces of tibiae and ventral surfaces of tarsi densely covered with golden, suberect setae; venter of abdomen also sparsely covered with golden, long pubescence (Figures 6 and 7). Description: Macropterous form (Figures 6 and 7). Coloration. Reddish brown to dark brown. Head, anterior lobe of pronotum, scutellum, pleura and sterna blackish brown; third and fourth segments of antenna brown; tarsi yellowish brown (Figures 6 and 7); hemelytron dark brown, with apical half of clavus, area between Pcu and Cu on corium and apical portion of membrane paler, base of costal area of membrane with a diffuse pale brown stripe ( Figure 8F).
Structure. Antennae, marginal area of head, disc of scutellum, pleura, sterna, coxae, ventral surfaces and apex of femora, tibiae, lateral margin of corium and venter of abdomen densely covered with golden, procumbent, short pubescence; first and second antennal segments, lateral margins of head and pronotum, femora and tibiae covered with brown, suberect to erect setae of varying lengths; apex of dorsal surfaces of tibiae and ventral surfaces of tarsi densely covered with golden, suberect setae; venter of abdomen also sparsely covered with golden, long pubescence (Figures 6 and 7). Head length is 1.41 times as long as width in male and about 1.46 times as long as width in female; median short sulcus on interocular space deep ( Figure 8A); width of interocellar space longer than width of ocellus ( Figure 8A); first visible segment of rostrum shortest, third segment about 1.12 times longer than first segment ( Figure 8B). Pronotum with anterior margin nearly straight, collar process prominent; anterior lobe of pronotum about 1.85 times longer than posterior lobe; lateral pronotal angle rounded ( Figure 8A). Fore tibia with fossula spongiosa occupying half of tibial length ( Figure 8D), mid tibia with fossula spongiosa occupying 1/3 of tibial length ( Figure 8E).
Male genitalia asymmetric (Figure 9). Pygophore oval in ventral view ( Figure 9A); median pygophore process long and extremely slender, apex sharp ( Figure 9A-C), nearly vertical in caudal view ( Figure 9B), curved in lateral view ( Figure 9C). Parameres sickleshaped, left paramere ( Figure 9D) slightly longer than right paramere ( Figure 9E). Phallus with phallobase feebly sclerotized, basal plate bridge feebly curved and slightly longer than basal plate ( Figure 9F); pedicel slightly curved and longer than basal plate ( Figure  9H,I). Dorsal phallothecal sclerite slightly sclerotized, broad and flat ( Figure 9F, H and I); lateral phallothecal sclerite moderately sclerotized, lower half of inner margin with two upward processes ( Figure 9I). Apical portion of endosoma with a somewhat petaloid process, surface of which is covered with tiny tubercles (Figure 9F,G). Head length is 1.41 times as long as width in male and about 1.46 times as long as width in female; median short sulcus on interocular space deep ( Figure 8A); width of interocellar space longer than width of ocellus ( Figure 8A); first visible segment of rostrum shortest, third segment about 1.12 times longer than first segment ( Figure 8B). Pronotum with anterior margin nearly straight, collar process prominent; anterior lobe of pronotum about 1.85 times longer than posterior lobe; lateral pronotal angle rounded ( Figure 8A). Fore tibia with fossula spongiosa occupying half of tibial length ( Figure 8D), mid tibia with fossula spongiosa occupying 1/3 of tibial length ( Figure 8E).

Remarks:
This new species is similar to S. brumalis comb. nov. and S. gracilis comb. nov., but it can be distinguished from those two species by the following characters: the body size is smaller (less than 10 mm in S. dominiqueae sp. nov. vs. over 12 mm in S. brumalis comb. nov. and S. gracilis comb. nov.), the pronotum is bicolored with the posterior lobe paler (vs. the pronotum unicolored in S. brumalis comb. nov. and S. gracilis comb. nov.), the first visible segment of rostrum is shorter than the third (vs. the first visible segment of rostrum longer than the third in S. brumalis comb. nov. and S. gracilis comb. nov.) and the fossula spongiosa is less prominent (the fore tibia with the fossula spongiosa occupying half of the tibial length, the mid tibia with the fossula spongiosa occupying 1/3 of the tibial length in S. dominiqueae sp. nov. vs. the fore tibia with the fossula spongiosa

Remarks:
This new species is similar to S. brumalis comb. nov. and S. gracilis comb. nov., but it can be distinguished from those two species by the following characters: the body size is smaller (less than 10 mm in S. dominiqueae sp. nov. vs. over 12 mm in S. brumalis comb. nov. and S. gracilis comb. nov.), the pronotum is bicolored with the posterior lobe paler (vs. the pronotum unicolored in S. brumalis comb. nov. and S. gracilis comb. nov.), the first visible segment of rostrum is shorter than the third (vs. the first visible segment of rostrum longer than the third in S. brumalis comb. nov. and S. gracilis comb. nov.) and the fossula spongiosa is less prominent (the fore tibia with the fossula spongiosa occupying half of the tibial length, the mid tibia with the fossula spongiosa occupying 1/3 of the tibial length in S. dominiqueae sp. nov. vs. the fore tibia with the fossula spongiosa occupying 2/3 of the tibial length, the mid tibia with the fossula spongiosa occupying half of the tibial length in S. brumalis comb. nov. and S. gracilis comb. nov.). (Miller, 1958) comb. nov. (Figures 10-12). Distribution: Indonesia (Papua). Diagnosis: Body brown with head, pronotum, scutellum, pleura and sterna dark brown; width of interocellar space subequal to width of ocellus; first visible segment of rostrum longer than third segment; pronotum with anterior margin nearly straight, collar process less prominent, lateral pronotal angle narrowly rounded; fore tibia with fossula spongiosa occupying 2/3 of tibial length, mid tibia with fossula spongiosa occupying half of tibial length.

Sigicoris gracilis
Redescription: Macropterous form (Figures 10 and 11). Coloration. Brown. Head, pronotum, scutellum, pleura and sterna dark brown; third and fourth segments of antenna and tarsi yellowish brown (Figures 10 and 11); hemelytron brown, with most of clavus, area between Pcu and Cu on corium, most base and marginal area of membrane paler, base of costal area of membrane with a pale brown securiform stripe ( Figure 12D).
Structure. Antennae, head, disc of scutellum, pleura, sterna, coxae, ventral surfaces and apex of femora, tibiae, lateral margin of corium and venter of abdomen densely covered with golden, procumbent, short pubescence; first and second antennal segments, lateral margins of head and pronotum, femora and tibiae covered with yellowish brown, suberect to erect setae of varying lengths; apex of dorsal surfaces of tibiae and ventral surfaces of tarsi densely covered with golden, suberect setae; venter of abdomen also sparsely covered with golden, long pubescence (Figures 10 and 11).
Head length is 1.24 times as long as width in male and about 1.36 times as long as width in female; median short sulcus on interocular space deep ( Figure 12A); width of interocellar space subequal to width of ocellus ( Figure 12A); first visible segment of rostrum about 1.37 times longer than third segment ( Figure 12C). Pronotum with anterior margin nearly straight, collar process less prominent ( Figure 12A); anterior lobe of pronotum 1.58 times longer than posterior lobe in male and about 1.45 times longer than posterior lobe in female; lateral pronotal angle narrowly rounded ( Figure 12A). Fore tibia with fossula spongiosa occupying 2/3 of tibial length ( Figure 12E), mid tibia with fossula spongiosa occupying half of tibial length ( Figure 12F). Insects 2022, 13, x FOR PEER REVIEW 18 of 27

Remarks:
The holotype of this species is deposited in Rijksmuseum van Natuurlijke Historie, Leiden. We only examined four paratypes of this species preserved in NHM and there is no additional specimen for dissection and DNA extraction. This species is very allied to S. brumalis comb. nov.; the characters currently used to separate it from the latter are the smaller body size, the paler coloration, the relatively larger ocellus, the straighter anterior margin of the pronotum with the less prominent collar process and the differences in the male genitalia as Miller illustrated [23]. Here, we still treat them as two valid species, but more evidence such as molecular data and carefully dissected structures of male genitalia are needed to further clarify the relationship between them.

Remarks:
The holotype of this species is deposited in Rijksmuseum van Natuurlijke Historie, Leiden. We only examined four paratypes of this species preserved in NHM and there is no additional specimen for dissection and DNA extraction. This species is very allied to S. brumalis comb. nov.; the characters currently used to separate it from the latter are the smaller body size, the paler coloration, the relatively larger ocellus, the straighter anterior margin of the pronotum with the less prominent collar process and the differences in the male genitalia as Miller illustrated [23]. Here, we still treat them as two valid species, but more evidence such as molecular data and carefully dissected structures of male genitalia are needed to further clarify the relationship between them.
Other  Diagnosis: Body dark brown, base of mid and hind tibiae and basal 1/3 of mid and hind femora yellowish white to pale yellow, hemelytron dark brown with three yellowish white spots, segment of connexivum with basal half yellowish white to yellow and apical half dark brown; width of interocellar space subequal to width of ocellus; first visible segment of rostrum longer than third segment; pronotum with anterior margin nearly straight, collar process prominent, lateral pronotal angle rounded; fore tibia with fossula spongiosa occupying half of tibial length, mid tibia with fossula spongiosa occupying 2/5 of tibial length.
Redescription: Macropterous form (Figures 13-15). Coloration. Dark brown. Head, anterior lobe of pronotum, scutellum, pleura and sterna blackish brown; antennae brown; Diagnosis: Body dark brown, base of mid and hind tibiae and basal 1/3 of mid and hind femora yellowish white to pale yellow, hemelytron dark brown with three yellowish white spots, segment of connexivum with basal half yellowish white to yellow and apical half dark brown; width of interocellar space subequal to width of ocellus; first visible segment of rostrum longer than third segment; pronotum with anterior margin nearly straight, collar process prominent, lateral pronotal angle rounded; fore tibia with fossula spongiosa occupying half of tibial length, mid tibia with fossula spongiosa occupying 2/5 of tibial length.
Redescription: Macropterous form (Figures 13-15). Coloration. Dark brown. Head, anterior lobe of pronotum, scutellum, pleura and sterna blackish brown; antennae brown; base of mid and hind tibiae and basal 1/3 of mid and hind femora yellowish white to pale yellow, tarsi yellowish brown (Figures 13-15); hemelytron dark brown except area between Pcu and Cu on corium and apical portion of membrane paler, three yellowish white spots present on hemelytron: a trapezoidal spot on conjunctive area of clavus, corium and membrane, a small, narrow, triangular spot on base of area between Sc and M on corium and a somewhat rectangular spot on base of costal area of membrane ( Figure 16F); segment of connexivum with basal half yellowish white to yellow and apical half dark brown (Figures 13, 14, 15 and 16G). base of mid and hind tibiae and basal 1/3 of mid and hind femora yellowish white to pale yellow, tarsi yellowish brown (Figures 13-15); hemelytron dark brown except area between Pcu and Cu on corium and apical portion of membrane paler, three yellowish white spots present on hemelytron: a trapezoidal spot on conjunctive area of clavus, corium and membrane, a small, narrow, triangular spot on base of area between Sc and M on corium and a somewhat rectangular spot on base of costal area of membrane ( Figure 16F); segment of connexivum with basal half yellowish white to yellow and apical half dark brown (Figures 13-15 and 16G). Structure. Antennae, marginal area of head, disc of scutellum, coxal cavities, coxae, ventral surfaces and apex of femora, tibiae, lateral margin of corium and genitalic part of abdomen densely covered with golden, procumbent, short pubescence; first and second antennal segments, lateral margins of head and pronotum, femora and tibiae covered with Structure. Antennae, marginal area of head, disc of scutellum, coxal cavities, coxae, ventral surfaces and apex of femora, tibiae, lateral margin of corium and genitalic part of abdomen densely covered with golden, procumbent, short pubescence; first and second antennal segments, lateral margins of head and pronotum, femora and tibiae covered with brown, suberect to erect setae of varying lengths; apex of dorsal surfaces of tibiae and ventral surfaces of tarsi densely covered with yellow to yellowish brown, suberect setae; venter of abdomen sparsely covered with golden, long pubescence (Figures 13-15).
Head length is 1.21 times as long as width in male and 1.28 times as long as width in female; median short sulcus on interocular space deep ( Figure 16A); width of interocellar space subequal to width of ocellus ( Figure 16A); first visible segment of rostrum about 1.18 times longer than third segment ( Figure 16B). Pronotum with anterior margin nearly straight, collar process prominent ( Figure 16A); anterior lobe of pronotum 1.62 times longer than posterior lobe in male and 1.39 times longer than posterior lobe in female, lateral pronotal angle rounded ( Figure 16A). Fore tibia with fossula spongiosa occupying half of tibial length ( Figure 16D), mid tibia with fossula spongiosa occupying 2/5 of tibial length ( Figure 16E); hemelytron with Pcu and Cu on membrane slightly curved, not so straight as those in other species of Sigicoris stat. nov. (Figure 16F). brown, suberect to erect setae of varying lengths; apex of dorsal surfaces of tibiae and ventral surfaces of tarsi densely covered with yellow to yellowish brown, suberect setae; venter of abdomen sparsely covered with golden, long pubescence (Figures 13-15). Head length is 1.21 times as long as width in male and 1.28 times as long as width in female; median short sulcus on interocular space deep ( Figure 16A); width of interocellar space subequal to width of ocellus ( Figure 16A); first visible segment of rostrum about 1.18 times longer than third segment ( Figure 16B). Pronotum with anterior margin nearly straight, collar process prominent ( Figure 16A); anterior lobe of pronotum 1.62 times longer than posterior lobe in male and 1.39 times longer than posterior lobe in female, lateral pronotal angle rounded ( Figure 16A). Fore tibia with fossula spongiosa occupying half of tibial length ( Figure 16D), mid tibia with fossula spongiosa occupying 2/5 of tibial length ( Figure 16E); hemelytron with Pcu and Cu on membrane slightly curved, not so straight as those in other species of Sigicoris stat. nov. (Figure 16F).

Remarks:
The original data of the examined specimens of Brachysandalus sexguttatus are "♂, Long. 8, Lat. 2 mill. Patria: Insula Mysol. (Mus. Holm.)". Stål did not designate the holotype and did not mention the number of specimens he examined [35]. We only found one male syntype of this species in NHRS and its label information matches the original data ( Figure 13). Here, we designate this specimen as the lectotype of B. sexguttatus.

Remarks:
The original data of the examined specimens of Brachysandalus sexguttatus are "♂, Long. 8, Lat. 2 mill. Patria: Insula Mysol. (Mus. Holm.)". Stål did not designate the holotype and did not mention the number of specimens he examined [35]. We only found one male syntype of this species in NHRS and its label information matches the original data ( Figure 13). Here, we designate this specimen as the lectotype of B. sexguttatus.
This species can be easily distinguished from other species of Sigicoris stat. nov. by the slightly curved Pcu and Cu on the membrane, the yellowish white spots on the hemelytron and the basal 1/3 of mid and hind femora yellowish white.

Discussion
Distribution and Habitat of Sigicoris stat. nov.
Sigicoris stat. nov. is endemic to New Guinea and mainly occurs in the mountainous area, especially along the Central Range which is cross-island from northwest to southeast ( Figure 17). Sigicoris brumalis comb. nov. is the most widespread species within Sigicoris stat. nov., which occurs almost transversely across the main island. S. dominiqueae sp. nov. is only distributed in Papua New Guinea, while S. gracilis comb. nov. and S. sexguttatus comb. nov. are only recorded from West Papua Province and Papua Province in Indonesia. Except the main island, the type locality of S. sexguttatus comb. nov. is Mysol Island (now Misool Island), which is an offshore island in West Papua with the highest point 561 m, and this is also the known westmost distribution of this genus.
The labels of most of the examined specimens involved altitudinal information. The altitude ranges of most Sigicoris stat. nov. species are relatively wide: from 300 m to 2250 m. The label information of S. dominiqueae sp. nov. specimens such as "light trap", "In logs" and "Under bark fallen hoop pine. Pine forest" could partly reflect the habitat and biology of this species. It can be inferred that species of this genus mainly live in forests; usually hide under barks, decaying logs or other shelters during daytime; become active at night; and can be attracted by the light. The above information expands our knowledge of insular species of Peiratinae to a certain extent, but deeper observation and research are still needed to explain some special biological phenomenon. This species can be easily distinguished from other species of Sigicoris stat. nov. by the slightly curved Pcu and Cu on the membrane, the yellowish white spots on the hemelytron and the basal 1/3 of mid and hind femora yellowish white.

Discussion
Distribution and Habitat of Sigicoris stat. nov.
Sigicoris stat. nov. is endemic to New Guinea and mainly occurs in the mountainous area, especially along the Central Range which is cross-island from northwest to southeast ( Figure 17). Sigicoris brumalis comb. nov. is the most widespread species within Sigicoris stat. nov., which occurs almost transversely across the main island. S. dominiqueae sp. nov. is only distributed in Papua New Guinea, while S. gracilis comb. nov. and S. sexguttatus comb. nov. are only recorded from West Papua Province and Papua Province in Indonesia. Except the main island, the type locality of S. sexguttatus comb. nov. is Mysol Island (now Misool Island), which is an offshore island in West Papua with the highest point 561 m, and this is also the known westmost distribution of this genus.
The labels of most of the examined specimens involved altitudinal information. The altitude ranges of most Sigicoris stat. nov. species are relatively wide: from 300 m to 2250 m. The label information of S. dominiqueae sp. nov. specimens such as "light trap", "In logs" and "Under bark fallen hoop pine. Pine forest" could partly reflect the habitat and biology of this species. It can be inferred that species of this genus mainly live in forests; usually hide under barks, decaying logs or other shelters during daytime; become active at night; and can be attracted by the light. The above information expands our knowledge of insular species of Peiratinae to a certain extent, but deeper observation and research are still needed to explain some special biological phenomenon.   Table S1: Information of newly sequenced species in the present study; Table S2: Information of sequences used in phylogenetic analysis.