Patrus subapicalis ( Ochs, 1930 ) Suksai & Gustafson & Sites & Sangpradub, 2021

Suksai, Benjamart, Gustafson, Grey T., Sites, Robert W. & Sangpradub, Narumon, 2021, Review of the Patrus landaisi species group from Thailand with description of three new species (Coleoptera, Gyrinidae), Zootaxa 4991 (3), pp. 561-591 : 584-585

Patrus subapicalis ( Ochs, 1930) stat. nov.

( Figs. 2H , 3H , 4H , 12 , 13A , 14B )

Orectochilus (Patrus) apicalis subapicalis Ochs, 1930: 20 (original description)

Patrus apicalis subapicalis Ochs, 1930 : Hájek & Fery 2017: 28 (new combination, catalogue)

Type locality. ‘ Nam Nat’ , Laos

Type material examined. PARATYPE female SMF C 9548, additional label information not provided to authors.

Other material examined. THAILAND: Chiang Mai Province: Doi Inthanon Natl. Park., Mae Klang at Ban Khun Klang , 18°31’N 98°31’E, 1296 m a.s.l., 18.V.2004, leg. A. Vitheepradit, T. Prommi, P. Laudee & P. Thamasenanupap, L-694, 1 female ( UMC) ; same locality except for, Huai Sai Luang Waterfall , 18°31’N 98°27’E, 1060 m a.s.l., 3.IV.2002, leg. UMC & CMU teams, L-321, 1 female ( UMC) ; same locality except for, 7.XII.2002, leg. CMU team, 3 males, 5 females ( UMC) ; same locality except for, 8.V.2002, leg. UMC & CMU teams, L-396, 2 males ( UMC) , 2 females ( THNHM, UMC) ; same locality except for, 13.I.2003, leg. CMU team, 2 males, 3 females ( UMC, THNHM) ; same locality except for, 14.III.2003, leg. CMU team, 2 females ( UMC) ; same locality except for, Mae Pan Waterfall , 18°31’N 98°27’E, 1100 m a.s.l., 3.IV.2003, leg. A. Vitheepradit, R.W. Sites & K. Seetaphan, L-442, 1 female ( UMC) ; same locality except for, Siriphum Waterfall (lowest level), 18°32’N 98°31’E, 1460 m a.s.l., 21.III.2002, leg. R.W. Sites, A. Vitheepradit & K. Kirawanich, L-315, 3 males ( UMC, THNHM) ; same locality except for, 9.V.2002, leg. UMC & CMU teams, L-401, 1 female ( UMC) ; Doi Suthep Natl. Park., Sai Yoi Waterfall , 18°48’N 98°55’E, 1100 m a.s.l., 5.V.2002, leg. CMU team, L-402, 2 males ( KKU, UMC) , 1 female ( KKU) ; same locality except for, 24.IX.2002, leg. CMU team, 4 males, 3 females ( UMC) ; same locality except for, 1 male ( KKU) ; same locality except for, 8.X.2002, leg. CMU team, 1 female ( UMC) ; same locality except for, 16.XI.2002, leg. CMU team, 1 male, 4 females ( UMC) ; same locality except for, 10.XII.2002, leg. CMU team, 1 female ( UMC) ; same locality except for, Kongma-Maesa Biosphere Reserve, Suthep Subdistrict, Mueang Chiang Mai District, 18°48’46.58”N 98°54’22.39”E, 1213 m a.s.l., 7.IV.2013, leg. K. Rattanachan, 3 females ( KKU) .

Diagnosis. Size: Male: 11.8–12.7 mm, female: 9.7–12.5 mm; body form in lateral view weakly dorsoventrally convex; elytral glabrous region of male ( Figs. 2H , 12A ) cordiform, along suture extending ca. 7/9 length of elytra, laterally expanded in anterior 2/3 to considerably wider than pronotal glabrous region, posterior 1/3 strongly acuminate with rounded margins; female elytral glabrous region ( Figs. 3H , 12E ) dissimilar to male, broad for nearentire length occupying 10/11 elytral width, lateral margins straight for 3/4 length creating parallel-sided appearance, abruptly acuminate medially in apical 1/4, posterolateral corners produced into points, posterior margin evenly convex toward suture; in lateral view width of pubescence margin at humeral region 2x as broad as that extending posterior; elytral apex of both sexes similar, obliquely truncate without apicolateral sinuation, epipleural angle distinct, weakly rounded; male protibia ( Fig. 4H ) wedge-shaped, without basal constriction, protibial apex obliquely truncate without prominent distolateral angle; male protarsus ( Fig. 4H ) ca. 3/4 length of protibia, protarsomeres 1–4 mostly similar in width; mesoventrite often without medial pit; aedeagus ( Fig. 12B–D ) with median lobe weakly constricted medially, parallel-sided in apical 1/3 before acumination, acumination short, 1/5 length of median lobe, apex triangular; female reproductive tract ( Fig. 12G ) without additional sclerotized structure between gonocoxae ( Fig. 12F ), fertilization duct as in Fig. 12H .

Differential diagnosis. Patrus subapicalis is most similar to P. apicalis , with which it was previously considered conspecific. They can be distinguished from each other by the differential diagnosis provided under P. apicalis . Females of this species are also similar to P. nanensis sp. nov., but can be distinguished by the differential diagnosis for the latter species.

Distribution. Patrus subapicalis was originally described from Laos and was previously known only from there. This is the first record of P. subapicalis from Thailand. Within Thailand, it is known only from the Thanon Thong Chai mountain range ( Fig. 14B ), where it has been collected sympatrically with P. garuda sp. nov. ( Fig. 13A ).

Discussion. Patrus subapicalis clearly exhibits species-level morphological differences from P. apicalis particularly in terms of the median lobe of the aedeagus. The results of the phylogenetic analyses also clearly support these two species as being distinct from one another ( Fig. 1 and supplementary Figs. S1–S 2 ). For these reasons, we here elevate P. subapicalis to species status.

Figures

FIGURE 1. Result of the single-locus Generalized Mixed Yule Coalescent (GMYC) species delimitation analysis using COI. Black branches denote interspecific-level divergences while red branches indicate intraspecific coalescence events. Values above nodes show posterior probability support for the ultrametric COI tree generated through BEAST used in the GMYC species delimitation analysis (see supplementary Fig. S2). Farthest outgroup not shown.

FIGURE 2. Dorsal habitus of males of P. landaisi species group: (A) P. apicalis; (B) P. corpulentus; (C) P. garuda sp. nov.; (D) P. landaisi; (E) P. nanensis sp. nov.; (F) P. phetchabunensis sp. nov.; (G) P. salvazai; (H) P. subapicalis. Scale bars = 4 mm.

FIGURE 3. Dorsal habitus of females of P. landaisi species group: (A) P. apicalis; (B) P. corpulentus; (C) P. garuda sp. nov.; (D) P. landaisi; (E) P. nanensis sp. nov.; (F) P. phetchabunensis sp. nov.; (G) P. salvazai; (H) P. subapicalis. Scale bars = 4 mm.

FIGURE 4. Left protibia and protarsus of males of P. landaisi species group: (A) P. apicalis; (B) P. corpulentus; (C) P. garuda sp. nov.; (D) P. landaisi; (E) P. nanensis sp. nov.; (F) P. phetchabunensis sp. nov.; (G) P. salvazai; (H) P. subapicalis. Scale bars = 2 mm.

FIGURE 12. Patrus subapicalis: (A) male pronotum and elytra, dorsal view, scale bar = 4 mm; (B) aedeagus, dorsal view, scale bar = 1 mm; (C) apex of median lobe, lateral view, scale bar = 1 mm; (D) apex of median lobe, ventral view showing operculum, scale bar = 1 mm; (E) female pronotum and elytra, dorsal view, scale bar = 4 mm; (F) gonocoxae, ventral view; (G) female reproductive tract, ventral view, scale bar = 1 mm; (H) fertilization duct, ventral view.

FIGURE 13. Habitats of P. landaisi species group: (A) stream at Siriphum Waterfall, Doi Inthanon National Park, Chiang Mai Province, habitat of P. garuda sp. nov. and P. subapicalis; (B) Benjamart Suksai in habitat of P. apicalis and P. salvazai at Nam Kuen stream, Chiang Rai Province; (C) shallow stream close to Ban Thai Samakkhi, Chiang Rai Province, habitat of P. landaisi and P. salvazai; (D) Tham Yai Waterfall Phu Kradueng National Park, Loei Province, habitat of P. phetchabunensis sp. nov.; (E) puddle in dry stream bed close to Ban Phithak Thai, Chiang Rai Province, habitat of P. landaisi and P. salvazai; (F) P. landaisi and P. salvazai from puddle in dry stream habitat close to Ban Thai Samakkhi, Chiang Rai Province.

FIGURE 14. (A–B) Distribution records of the P. landaisi species group in Thailand.