Amara (Curtonotus) beijingensis, Li & Li & Shi, 2024

Li, Yihang, Li, Haoyuan & Shi, Hongliang, 2024, Revision of the macropterous subgenus Curtonotus from east China, with the description of a new species (Carabidae, Zabrini, Amara), ZooKeys 1190, pp. 39-73 : 39

Amara (Curtonotus) beijingensis sp. nov.

Fig. 1

Type material.

Holotype: male (IZAS), Beijing, Mentougou District, Xiaolongmen Forest Park, 1100 m, 2018.08.16-21 [in Chinese]. Paratypes, a total of 13 males and 29 females (6 males, 15 females in IZAS, 7 males, 14 females in CBJFU), all with the same localities as holotype, but in different collecting date: 2 females, 2014.08.17-22; 5 males, 7 females, 2015.08.16-21; 2 males, 11 females, 2016.08.17-22; 1 male, 1 female, 2017.08.16-21; 1 male, 1 female, 2018.08.17-22; 1 female, 2019.08.16-21; 5 females, 2021.08.16-21; 4 males, 1 female, 2022.08.17-23.

Chinese common name.

北京暗步甲.

Diagnosis.

A species from the Amara macronota species group, with black dorsum, relatively wide head, and with two supraorbital setae; pronotum widest a little before middle; lateral margins evenly curved, narrowed and slightly sinuate before posterior angles; posterior angles evidently protruded laterally; mid-anterior area densely punctate; elytra striae distinctly punctate except near to apex; male mesotibial projection distinct, composed of two denticles: the proximal denticle is larger, its basal margin extended to form a wide triangular projection; the distal denticle is much smaller (~ 1/3 length of the proximal one), near midpoint between the proximal denticle and tibial apex; apical lamella of male genitalia large, slightly declined to right, apex rounded.

Comparison.

Among the Chinese species of subgenus Amara Curtonotus , A. (C.) beijingensis sp. nov. is most similar to A. (C.) macronota for the following characteristics: two supraorbital setae present, pronotum basal area and elytral striae both distinctly punctate; pronotum anterior angles slightly protruded; male mesotibiae with two distinct denticles on inner margin; gonocoxite 2 of ovipositor very short. However, the new species is different from A. (C.) macronota in the following characteristics: elytral striae, pronotum basal and mid-anterior area with fine and dense punctures; pronotum lateral margins very slightly sinuate before the posterior angles which are less laterally protruded; elytra basal border curved upward, and apical lamella of median lobe much longer and wider, and more evidently declined to the right side, in dorsal view, apex widely rounded but not attenuate. In contrast, A. (C.) macronota has much coarser and denser punctures on elytral striae, pronotum basal and mid-anterior area; pronotum lateral margins evidently sinuate before the posterior angles which are clearly protruded laterally; elytra basal border nearly straight; and male genitalia with the apical lamella rounded-triangular, evidently attenuate to apex, not declined to the right side.

The new species A. (C.) beijingensis resembles other two species from China, A. (C.) hiogoensis Bates, 1873 and A. (C.) harpaloides Dejean, 1828. Compared with the new species, A. (C.) hiogoensis can be distinguished in the elytra with very indistinct microsculpture; pronotum without punctures on the mid-anterior area; and gonocoxite 2 of ovipositor a little longer. A. (C.) harpaloides can be distinguished from the new species in the finer punctures on pronotum and elytral striae; apical lamella of male genitalia different in shape; gonocoxite 2 of ovipositor much longer; and female with stronger elytra microsculpture.

There are six other species ( A. (C.) brevicollis , A. (C.) dux , A. (C.) gansuensis Jedlicka, 1957, A. (C.) banghaasi Baliani, 1933, A. (C.) fodinae , and A. (C.) harpaloides ) of Amara Curtonotus in the mountain region situated west of Beijing, which may live in sympatry with A. (C.) beijingensis sp. nov. Compared with the new species, A. (C.) brevicollis and A. (C.) dux are different in the reddish brown dorsal surface and very fine pronotal punctures; A. (C.) gansuensis is different in the head with only one supraorbital seta; A. (C.) banghaasi is different in the pronotum widest point far before middle and anterior angles not protruded; A. (C.) fodinae is different in narrower pronotum and pronotum lateral margin curved longer before posterior angle.

We also compared the new species with all Amara Curtonotus species recorded from nearby countries including Russia, Japan, Mongolia, North Korea and South Korea. A. (C.) beijingensis sp. nov. can be distinguished from most of these species by the combination of following characteristics: head with two supraorbital setae; antennomere 1 in similar color as rest segments; pronotum widest near middle, posterior angles acute and laterally protruded; pronotum disc with distinct punctures confined in the mid-anterior area. Among these species, A. (C.) beijingensis sp. nov. is externally very similar to A. (C.) gebleri Dejean, 1831 Dejean which was recorded from Mongolia and the Russian Far East. A. (C.) gebleri is different from the new species in the head a little more thickened; apical lamella of male genitalia rounded-triangular, gradually attenuate to apex, with length lesser than greatest width; gonocoxite 2 of ovipositor much more elongate. A. (C.) beijingensis sp. nov. is also similar to A. (C.) propinqua Ménétriés, 1832 which was recorded from Mongolia and Middle Asia. A. (C.) propinqua is different from the new species in the pronotum widest point far before middle; pronotum mid-anterior area only with very scarce punctures; right margin of the median lobe of male genitalia strongly swollen at middle.

Description.

(Habitus in Fig. 1A ) Size relatively large in the genus, BL = 13.0-14.6 mm, body form rather robust; dorsum black, elytra black with shinny surface; antennae, mouthparts and tarsomeres dark reddish brown; venter black. Head relatively thick, distinctly shorter than pronotum (HW/PW = 0.5-0.6); frons sparsely wrinkled, frontal fovea short, reaching middle level of eyes; with two supraorbital setae; eyes large, hemispheric; antennae nearly reaching pronotum base. Pronotum (Fig. 1B ) nearly circular, widest a little before middle; pronotum wider than long (PW/PL = 1.44-1.50); basal margin a little longer than anterior margin (PAW/PBW = 0.74-0.78); anterior angles slightly protruded, rounded at apex; lateral margins evenly curved, slightly constricted before posterior angles, mid-lateral setae before middle; posterior angles small, acuminate, distinctly protruded, forming evident denticle. Basal surface densely punctate, punctures reaching region between basal fovea; inner groove short and faint, a little distant from basal margin; outer groove well incised, with distinct outer margin, reaching basal margin, approximately 1/4 length of pronotum. Disc convex, smooth at middle, slightly transversely wrinkled; mid-anterior region densely punctate; lateral grooves slightly widened, distinctly punctate; median line fine but distinct. Elytra oblong, EL/EW = 1.40-1.50, widest point near middle, lateral margins subparallel before middle; basal border weakly bent forward, extending toward humeral angles; basal border and lateral margin forming an obtuse angle, with small and narrow denticle, not protruded. Basal setigerous pores absent; parascutellar striae deep as other striae, its apex joint to stria 1; all striae well incised, distinctly punctate except near to apex; punctures dense and coarse near base, gradually reducing in size to elytral apex; third interval without discal setigerous pore; ninth interval with umbilical series regularly composed of 13 pores. Elytra with isodiametric microsculpture in both sexes, quite evident on disc, very shallow near apex. Hind wings fully developed. Ventral side. Proepisternum, mesepisternum, and metepisternum heavily punctate, metepisternum lateral side twice length as basal width; abdominal sternites III-IV punctate and wrinkled except in middle, coarse area gradually narrowed from proximal sternites to distal ones; sternite VII with two pairs of marginal setae in females, with one pair in males. Legs. Male mesotibiae projection composed of two denticles on inner margin (Fig. 1C ): proximal denticle larger, near middle of tibiae, with acute apex; distal one much smaller, on the middle point of the proximal denticle and distal end of tibiae. All tarsomeres with setae underside. Male genitalia. (Fig. 1D ). Median lobe of aedeagus bent greater than 90 degrees; apex in lateral view gradually attenuate, a little deflected and then bent downward; dorsal margin gradually narrowed toward apex; ventral margin near straight at middle; in dorsal view, apical lamella (Fig. 1F ) with maximum width subequal to length, apex rounded, slightly declined to right; apical orifice small, nearly middle placed; right paramere (Fig. 1E ) long, apical half slender and gradually curved, a little thickened to apex, apex rounded without hook. Female genitalia. (Fig. 1G ) Gonocoxite 2 of ovipositor very short, length a little greater than greatest width, inner and outer margin each with one ensiform seta before widest point, apex widely rounded.

Distribution.

Only known from the type locality in western Beijing, China. Considering it has fully-developed hind wings, this species may also be found in nearby provinces.

Etymology.

The scientific name of the new species comes from its type locality, Beijing.

Remarks.

All types of this new species were collected by the undergraduate students of Beijing Forestry University attending Forestry Cognition Field Practice in the same locality (Xiaolongmen Forest Park, Mentougou, Beijing) in late August repeatedly during the past nine years. Many of these specimens were collected by pitfall traps under (or beside) different types of forest and others were randomly hand-collected along trails. For each year, more than 100 students attend this field practical. Thus, very few of these specimens have the collector’s name recorded. Moreover, due to the difficulty to identify Amara Curtonotus species in the field and mixture of specimen from various habitats, the specific habitat of the new species remains unknown for now. It is inferred that A. (C.) beijingensis sp. nov. inhabits in forest edges, like many other Amara Curtonotus species found in the same area such as A. (C.) harpaloides and A. (C.) gansuensis . Although the new species is most similar to A. (C.) macronota , we hypothesize that these two species prefer different habitats and altitudes in the area around Beijing. Amara (C.) beijingensis sp. nov. was only collected in temperate broad-leaf forests above 1000 m elevation, while A. (C.) macronota was found in various open habitats in plain areas of Beijing. Besides, A. (C.) beijingensis sp. nov. possibly shares the same habitat with A. (C.) harpaloides , as both species were collected by light trap around Xiaolongmen Forest Park.

Supplementary notes on recorded species from eastern and central China

Amara (Curtonotus) gigantea species group

This species group contains only one species which is special among all Chinese Amara Curtonotus for its largest body size, strongly thickened head, well-developed projection on male mesotibiae, and large apical lamella of the male genitalia.

Figures

Figure 1. Amara (Curtonotus) beijingensis sp. nov. A dorsal habitus, male (holotype) B pronotum posterior angle C male mesotibia D lateral view of aedeagus E right paramere F dorsal view of apical lamella of aedeagus G gonocoxite 2 of ovipositor. Scale bars: 5 mm (A); 1 mm (B-E); 0.5 mm (F, G).