Review of the ant genus Manica (Hymenoptera, Formicidae), with a new record of the genus in China and description of a new species

Seven known extant species of Manica have been identified worldwide: M. bradleyi (Wheeler, 1909), M. hunteri (Wheeler, 1914), M. invidia Bolton, 1995, M. parasitica (Creighton, 1934), M. rubida (Latreille, 1802), M. shanyii sp. nov. , and M. yessensis Azuma, 1955. The discovery of the new species is documented from Sichuan Province, China, marking the first recorded instance of the genus Manica in China. Additionally, an identification key for distinguishing the known species within the genus Manica is provided.


Introduction
The genus Manica, first described by Jurine in 1807, traces its origins to at least the Eocene epoch (Zharkov et al. 2023).Presently, Manica stands out as a rare genus in ants, classified within the tribe Myrmicini of the subfamily Myrmicinae.However, the morphological definition of the tribe Myrmicini has been challenging due to a lack of distinctive characteristics (Jansen and Savolainen 2010).Initially, Myrmicini was defined based on several morphological features, many of which were not exclusive to Myrmicini, encompassing seven genera (Bolton 2003).Recent molecular studies have suggested that the tribe may not be monophyletic (Brady et al. 2006;Moreau et al. 2006), although there were discrepancies regarding the genera included in the tribe.It was only later, with the work conducted by Ward et al. (2015), that the membership of Myrmicini was restricted to two genera, Manica and Myrmica, establishing its position as sister to all other members of the subfamily.
Currently, only six extant species and two fossil species of Manica are recognized in the Holarctic region.Among these, M. rubida (Latreille, 1802) is distributed in Europe (Borowiec 2014); while four species, namely, M. bradleyi (Wheeler, 1909), M. hunteri (Wheeler, 1914), M. invidia Bolton, 1995 and M. parasitica (Creighton, 1934), are found in western North American.Manica yessensis Azuma, 1955 is endemic to Japan, representing the sole recorded species of Manica in Asia so far.Despite extensive surveys in the region, no additional species of this genus have been discovered in the past 70 years.However, given the extant distribution of this genus in Japan and southern Europe, with China's vast expanse offering numerous habitats suitable for Manica, it is plausible that cryptic, undiscovered species of Manica may exist in China.
In this study, while examining ants from the Emei and Gongga Mountains in Sichuan Province, China, we identified a new species of the genus Manica, marking the first documented occurrence of the genus and a new species in China.Here, we describe this new species and recognize the six known extant species, providing an identification key to Manica species based on the worker caste.

Materials and methods
The specimens of Manica shanyii sp.nov.were collected alive during field expeditions to Emei and Gongga Mountains in Sichuan, China (Fig. 1) by hand.Subsequently, they were preserved in a vial containing absolute ethyl alcohol.The specimens were then pin-mounted and examined using a Leica M205A stereomicroscope.High-quality multifocused montage images were generated with a KEYENCE (VHX-6000) digital imaging system.
The images of the Manica species, accessible on AntWeb (https://www.antweb.org), were meticulously examined and compared.The general terminology for Manica workers adheres to Bolton (1975).All measurements are given in millimeters.The abbreviations employed for the measurements and indices are as follows:

ED
Eye Diameter, maximum diameter of eye.

HL
Head Length, straight-line length of head in full-face view, measured from midpoint of anterior clypeal margin to midpoint of posterior margin, or terminal horizontal line in some species with a concave posterior margin.

HW
Head Width, maximum width of head in full-face view, excluding eyes.

MSL
Mesosoma Length, diagonal length of mesosoma in lateral view, measured from point at which pronotum meets cervical shield to posterior basal angle of metapleuron.

PH
Petiole Height, height of petiole measured in lateral view from apex of ventral (subpetiolar) process vertically to a line intersecting dorsal most point of node.

PL
Petiole Length, length of petiole measured in lateral view from anterior process to posterior most point of tergite, where it surrounds gastral articulation.

PW
Pronotal Width, maximum width of pronotum measured in dorsal view.

SL
Scape Length, straight-line length of antennal scape, excluding basal constriction or neck.

TL
Total Length, total outstretched length of individual, from mandibular (occlusion) apex to gastral apex (not including the sting).
The holotype and paratypes specimens have been or will be deposited in the following institutions: GXNU Insect Collection, Guangxi Normal University, Guilin, Guangxi, China.IZCAS Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Diagnosis.Head and gaster blackish brown to black, while mesosoma yellow.In lateral view, postpetiole as broad as its long, with an evenly convex anterior margin and a unconspicuous posterior margin; ventral surface flat, lacking any pointed protuberance.Petiole and postpetiole smooth and shining.
Recognition.M. bradleyi (Wheeler, 1909) and M. yessensis Azuma, 1955, are easily distinguishable from all other species of Manica due to their distinctive characteristics.They both feature a black or dark brown head and gaster, contrasted with a light brown to reddish yellow mesosoma.Furthermore, M. bradleyi can be easily identified from M. yessensis by its postpetiole, which is as long as its high in lateral view, with a distinctly conically protuberant anteroventral corner; the dorsal face of the postpetiole is evenly and slightly convex, while both the petiole and postpetiole exhibit a smooth and shining appearance (Fig. 2C, D).
Distribution.In the Sierra Nevada Mountains of California, western Nevada, and the Transverse Ranges in southern California, with a single record from the Cascade Range of Oregon.(Wheeler, 1914) Fig. 3 Myrmica (Oreomyrma) hunteri Wheeler, 1914: 121, fig. 1c (w.)  Diagnosis.Body uniformly brownish yellow.In lateral view, dorsum feebly convex, with posterolateral corner of propodeum obtusely angular.Additionally, in lateral view, postpetiole compressed anteroposteriorly, distinctly higher than long.The lateral face of mesosoma longitudinal striae without puncta, while petiole and postpetiole smooth and not shining.

Manica hunteri
Recognition.M. hunteri (Wheeler, 1914) and M. invidia Bolton, 1995 can be easily distinguished from the congeners of this genus by their uniformly brownish yellow, or reddish brown to blackish.While M. hunteri may initially resemble an immature M. invidia, closer examination reveals distinct characteristics that differentiate them.In lateral view, the postpetiole of M. hunteri compressed anteroposteriorly, distinctly higher than long.Additionally, the lateral face of mesosoma exhibits longitudinal striae without puncta, and both petiole and postpetiole are smooth and shining (Fig. 3D).
Distribution.From northern Utah and northern Nevada to central California, extending northwards into southern Canada.The northernmost is Edmonton, Alberta, while the easternmost range extends to Sundance, Wyoming.Recognition.M. invidia Bolton, 1995 bears resemblance to M. hunteri (Wheeler, 1914), yet it can be distinguished by the following characteristics: in lateral view, the Type material.Unexamined, but high-resolution images of syntype worker (CASENT0005974, imaged by April Nobile) were reviewed.

Manica invidia
Diagnosis.Body almost uniformly light blackish brown.Head smooth and shining, except for the frontal area and cheek with longitudinal stripes.Similarly, mesosoma and metasoma smooth and shining, except for katepisternum and the lower part of lateral face of propodeum with finely punctate-striate patterns.
Recognition.M. parasitica (Creighton, 1934) can be easily distinguished from the congeners of this genus by the characteristics mentioned in the "Diagnosis" of this species.
Distribution.This species is only known from a few records in the Sierra Nevada Mountains in California.
Manica rubida (Latreille, 1802) Fig. 6 Diagnosis.Body reddish brown with gaster blackish brown.In lateral view, with posterolateral corner of propodeum obtusely angular.Petiole node in lateral view with an almost vertical posterior face.Postpetiolar node in lateral view with a vertical posterior face; postpetiolar sternite anteroventrally produced as an acute angle directed forward.(Latreille, 1802) can be easily distinguished from the congeners of this genus by the following characteristics: the body is reddish-brown with a gaster that is distinctly darker than the reddish-brown head.Additionally, in lateral view, the petiolar node is erect, exhibiting distinct anterior and posterior margins along Diagnosis.Body brownish black.In full-face view, head longer than broad, with broadly rounded posterior corners; the anterior margin of clypeus narrowly rounded, without prominent botches medially; the antennal scapes slightly surpass the posterior corners of the head.In lateral view, the dorsum of propodeum roughly straight, with obtusely angular posterolateral corners.Petiole in lateral view slightly longer than high, with a slightly concave anterior margin and a dorsal outline more or less narrowly rounded; the subpetiolar process in lateral view acutely toothed anteroventrally.Similarly, the postpetiole in lateral view as broad as long, with a convex anterior margin and steep posterior margin; the sternite slightly convex, with rounded anteroinferior corners.
Description.Head.In full-face view, the head longer than broad, with slightly convex lateral margins and broadly rounded posterior corners, while the posterior margin nearly straight (Fig. 7A).Mandibles slightly convex and armed with one large apical tooth, one secondary tooth, and followed by five smaller teeth.The anterior margin of clypeus relatively narrowly rounded, with a prominent upward edge in the middle.Frontal carinae curved outwards to merge with the rugae surrounding the antennal sockets, but they not reaching to middle of head (Fig. 7A).Frons wide, frontal lobes not extended.Antennae 12-segmented, featuring with a distinct 5-segmented club; scape relatively long, slightly surpassing the posterior corners of the head, and gradually curved at the base, without any trace of lobe or carina (Fig. 7A).Ocelli absent.Eyes relatively large, located slightly before the mid-point of the lateral sides of the head (Fig. 7A).Mesosoma.In lateral view, promesonotum evenly convex; metanotal groove strongly depressed; propodeum roughly straight, passing through a distinct, but obtuse angle or obtuse roundness into the somewhat straight and sloping declivity (Fig. 7C).In dorsal view, rather robust, with a faint but visible promesonotal suture; lateral margins slightly convex, anterior margin convex, and posterior margin slightly concave (Fig. 7B).Metasoma.Petiole in lateral view with a very short peduncle, slightly longer than high, with a slightly concave anterior margin and a dorsum of node that more

A B C
or less narrowly rounded, while posterior margin slightly convex (Fig. 7C); in dorsal view subcampanulate, longer than broad, with a relatively narrow anterior margin and slightly convex lateral margins.Subpetiolar process in lateral view acute toothed anteroventrally (Fig. 7C).Postpetiole in lateral view as long as high, anterior margin rising in a gentle slope towards the posterior margin and then abruptly descending (Fig. 7C); in dorsal view clearly larger than petiole, roughly pyriform, with a relatively narrow anterior margin and slightly convex lateral margins (Fig. 7B); postpetiolar sternite in lateral view slightly convex, with rounded anteroinferior corners (Fig. 7B).Gaster in lateral view elliptical (Fig. 7C).Sculpture.Mandibles longitudinally striate (Fig. 7A).Clypeus smooth and shining, antennal scape finely punctate.The posterior portion of the head longitudinally striate, with densely punctate spaces between them (Fig. 7A).Promesonotal rugae extend laterally, the lower part of mesopleuron and metapleuron longitudinally striate (Fig. 7C).Pronotum with finely transverse rugae, mesonotum densely transversely striate, and anterodorsal propodeum sparsely transversely striate, with shining declivity (Fig. 7B).Dorsum of petiole sparsely rugose and punctate (Fig. 7C).Gaster smooth and shining.Pilosity.Body entirely covered erect to suberect and yellowish hairs.Antennal scape with subdecumbent hairs.Coloration.Body reddish brown to blackish brown (Fig. 7).
Recognition.Manica shanyii sp.nov.can be easily distinguished from its congeners by the following characteristics: the entire dorsum of mesosoma exhibits transverse striation and punctae, and masticatory margin of mandibles only with seven teeth, comprising one large apical tooth, one secondary tooth, and followed by five smaller teeth.
Distribution.Emei and Gongga Mountains in Sichuan, China.
Habitat.The nest of Manica shanyii sp.nov.was discovered in the Gongga Mountain National Nature Reserve and Emei Mountain National Nature Reserve, Sichuan, China.The sampled sites are positioned within a mixed coniferous broad-leaved forest, where the ants were found inhabiting dead wood on the forest floor covered with brown forest soil.
Etymology.This species is named after Professor Zhou Shanyi from Guangxi Normal University, China, in recognition of his significant contributions to the field of ant taxonomy in China. in lateral view higher than long; sternite of postpetiole anteroventrally produced as a blunt angle directed forward.Petiole and lateral face of postpetiole rugose-punctate.Recognition.M. yessensis Azuma, 1955 is closely related to M. bradleyi (Wheeler, 1909), but it can be separated from the latter by the following characteristics: the posterodorsal corner of propodeum in lateral view is obtusely angular; the postpetiole in lateral view is higher than long; the sternite of postpetiole is anteroventrally produced as a blunt angle directed forward; and both the petiole and the lateral face of postpetiole exhibit rugose-punctate patters.

Manica yessensis Azuma, 1955
Distribution.This species is found exclusively in the northern and central regions of Japan.

Discussion
Zharkov et al. ( 2023) described a Baltic amber -Manica andrannae, which from the Kaliningrad region of Russia (formerly part of the Palaearctic Region).This newly described taxon is the first fossil species of the genus Manica, serving as an important link in understanding the origin and evolution of this genus.Among the known nine species of the genus Manica, four extant species (M.bradleyi, M. hunteri, M. invidia, M. parasitica) and one extinct species ( †M. iviei) are predominantly distributed in the western part of the Nearctic Region, two species ( †M. andrannae, M. rubida) are concentrated in the western part of the Palaearctic Region, one species (M.yessensis) is found in Japan in the eastern part of the Palaearctic Region, and the newly discovered species (M.shanyii) is distributed in the southernmost part of the Palaearctic Region.Based on the current distribution, North America evidently serves as the center of species diversity for the genus Manica (Fig. 1).Zharkov et al. (2023) hypothesized that the genus Manica may have originated in the Nearctic Region and later dispersed to the Palearctic Region.However, based on the "Diversification rate hypothesis" (Wiens and Dykhuizen 2011), regions with high species diversity do not necessarily indicate older taxa in that area.Therefore, inferring the Nearctic Region as the center of origin for the genus Manica solely based on species distribution, although plausible, remains contentious.However, the discovery sites and formation times of fossils can provide valuable insights into the origin of species.Despite fossil distribution in both the Nearctic Region and the Palaearctic Region, fossil species of †M.andrannae in the Palaearctic Region was formed during the Middle to Late Eocene, while the †M.iviei in the Nearctic Region was formed during the Oligocene.Consequently, the fossil species in the Palaearctic Region are older, hinting that the earliest Manica might have been distributed in the Palaearctic Region, particularly in Europe, during the Eocene.Based on this, we hypothesize that Manica possibly originated in the mid-Eocene, with its center of origin in Europe within the Palaearctic Region, before dispersing to the Nearctic Region over long distances.As for species in East Asia, they might have originated from species in the Nearctic Region through the Bering Land Bridge or from European species dispersing to East Asia over long distances.Discovering new species or records of this genus in Central Asia in the future could somewhat support the latter hypothesis.Of course, for a systematic elucidation of the origin and dispersal of Manica, future biogeographical studies based on phylogenetic relationships could be conducted.

Figure 2 .
Figure 2. Manica bradleyi worker (Syntype, images cited from https://www.antweb.org/,CASENT0907664, imaged by Alexandra Westrich) A head in full-face view B label C body in dorsal view D body in lateral view.

Figure 3 .Figure 4 .
Figure 3. Manica hunteri worker (Non-type, images cited from https://www.antweb.org/,CASENT0922741, specimen's photos by Wade Lee, label's photo by Michele Esposito) A head in full-face view B label C body in dorsal view D body in lateral view.

Figure 5 .
Figure 5. Manica parasitica worker (Syntype, imaged cited from https://www.antweb.org/,CASENT0005974, imaged by April Nobile) A head in full-face view B label C body in dorsal view D body in lateral view.

Figure 6 .
Figure 6.Manica rubida worker (Non-type, imaged cited from https://www.antweb.org/,CASENT0173135, specimen's photos by April Nobile, label's photo by Michele Esposit) A head in fullface view B label C body in dorsal view D body in lateral view.

Figure 7 .
Figure 7. Manica shanyii sp.nov.worker (Holotype, imaged by Yuqing He) A head in full-face view B body in dorsal view C body in lateral view.

Fig. 8 Figure 8 .
Figure 8. Manica yessensis worker (Paratype, images cited from https://www.antweb.org/,CASENT0900372, imaged by Ryan Perry) A head in full-face view B label C body in dorsal view D body in lateral view.
Type material.Unexamined, but high-resolution images of syntype worker (CASENT0904061, imaged by Alexandra Westrich) were reviewed.Diagnosis.Body dully yellow or nearly orange.In lateral view, posterolateral corner of propodeum broadly rounded.Furthermore, in lateral view, postpetiole as long as