Pterostichus phiaoc, Zaitsev & Zaitsev, 2019

Fedorenko, D. N., 2019, New species of Pterostichus subgenus Circinatus (Coleoptera: Carabidae: Pterostichini) from Vietnam, Russian Entomological Journal 28 (4), pp. 358-369 : 363

KEY TO SPECIES OF CIRCINATUS FROM VIETNAM.

1(2) Elytron with two discal setae and no basolateral bead. Sides of pronotum deeply sinuate in front of right and sharp basal angles, each side bisetose. — Cao Bang Province ............................................ 1. P. phiaoc sp.n.

2(1) Elytron with one discal seta near middle; sides of pronotum barely sinuate in front of very obtuse to widely rounded basal angles, each side with 1–2 setae.

3(10) Pronotum with two lateral setae on each side, anterior and posterior.

4(7) Pronotum with posterolateral seta in basal angle and either base slightly wider than apex and basal angles distinct or sides subsinuate in front of rounded basal angles. Meso- and metatarsomeres 1–3 each with a sharp outer lateral sulcus/carina. Pronotal and elytral microsculpture consisting of dense transverse lines.

5(6) Pronotum subquadrate, with distinct basal angles, entire apical bead and two basal sulci on each side; inner sulcus being short, running close to lateral margin and anteriorly merging into lateral groove. Elytron with a distinct humeral tooth extended into basolateral bead; no parascutellar striole. BL 11.4 mm. — Cao Bang Province ......................................................... 2. P. caobang sp.n.

6(5) Pronotum cordate, subsinuate in front of rounded basal angles, with apical bead obliterate medially. Elytron with a long parascutellar striole, nearly indistinct humeral tooth, and basolateral bead missing. BL 15.4 mm. — Cao Bang Province ................................ 3. P. expolitus sp.n.

7(4) Pronotal posterolateral seta much in front of basal angle, sides (sub)convex in front of rounded basal angles. Meso- and metatarsi without outer lateral sulcus/carina. Pronotal and elytral microsculpture consisting of slightly transverse or very transverse meshes, respectively.

8(9) Body slender, pronotum barely longer; elytra very narrow basally; mesepisterna in dorsal view traceable just in front of nearly indistinct elytral humeri. Meshes of elytral microsculpture moderately transverse. — Lao Cai Province .......................................... 4. P. phangxipang sp.n.

9(8) Body slightly more robust, pronotum barely shorter; elytra wide basally, with humeri widely rounded and mesepisterna concealed in dorsal view. Meshes of elytral microsculpture transverse and very narrow. — Lao Cai Province ....................................... 5. P. hoanglien sp.n.

10(3) Pronotal posterolateral seta missing.

11(12) Elytral base beaded laterally. Body more robust due to shorter pronotum and elytra, pronotum barely wider than long, with sides straight behind middle,EL/EW 1.6.Pronotal and elytral microsculpture consisting of moderately or very transverse meshes, respectively. Only meso- and metatarsomere 1 with a nearly indistinct lateral sulcus. — Lao Cai Province ....................... 6. P. batxatensis sp.n.

12(11) Elytral base without lateral bead. Body slender because of pronotum and elytra longer, pronotum barely longer than wide, with sides subsinuate behind middle, EL/EW 1.8. Pronotal and elytral microsculpture consisting of dense transverse lines. Meso- and metatarsomeres 1–3 each with a distinct outer lateral sulcus. — Lao Cai Province ..................................... 7. P. laocaiensis sp.n.